More aggressive Recorder V1 charging (patch #1116884 from Jerry Van Baren)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@6105 a1c6a512-1295-4272-9138-f99709370657

7 files changed, 507 insertions, 494 deletions

diff --git a/apps/debug_menu.c b/apps/debug_menu.c
index 815eb5af67..7b81869e69 100644
--- a/apps/debug_menu.c
+++ b/apps/debug_menu.c
@@ -968,7 +968,7 @@ bool dbg_mas_codec(void)
  * The power_history array is updated in power_thread of powermgmt.c.
  */
 
-#define BAT_FIRST_VAL  MAX(POWER_HISTORY_LEN - LCD_WIDTH - 1, 0)
+#define BAT_LAST_VAL  MIN(LCD_WIDTH, POWER_HISTORY_LEN)
 #define BAT_YSPACE    (LCD_HEIGHT - 20)
 
 bool view_battery(void)
@@ -986,30 +986,32 @@ bool view_battery(void)
         switch (view) {
             case 0: /* voltage history graph */
                 /* Find maximum and minimum voltage for scaling */
-                maxv = minv = 0;
-                for (i = BAT_FIRST_VAL; i < POWER_HISTORY_LEN; i++) {
+                maxv = 0;
+                minv = 65535;
+                for (i = 0; i < BAT_LAST_VAL; i++) {
                     if (power_history[i] > maxv)
                         maxv = power_history[i];
-                    if ((minv == 0) || ((power_history[i]) && 
-                                        (power_history[i] < minv)) )
+                    if (power_history[i] && (power_history[i] < minv))
                     {
                         minv = power_history[i];
                     }
                 }
                 
-                if (minv < 1)
+                if ((minv < 1) || (minv >= 65535))
                     minv = 1;
                 if (maxv < 2)
                     maxv = 2;
                     
                 lcd_clear_display();
-                lcd_puts(0, 0, "Battery voltage:");
+                snprintf(buf, 30, "Battery %d.%02d", power_history[0] / 100,
+                         power_history[0] % 100);
+                lcd_puts(0, 0, buf);
                 snprintf(buf, 30, "scale %d.%02d-%d.%02d V", 
                          minv / 100, minv % 100, maxv / 100, maxv % 100);
                 lcd_puts(0, 1, buf);
                 
                 x = 0;
-                for (i = BAT_FIRST_VAL+1; i < POWER_HISTORY_LEN; i++) {
+                for (i = BAT_LAST_VAL - 1; i >= 0; i--) {
                     y = (power_history[i] - minv) * BAT_YSPACE / (maxv - minv);
                     lcd_clearline(x, LCD_HEIGHT-1, x, 20);
                     lcd_drawline(x, LCD_HEIGHT-1, x, 
@@ -1035,31 +1037,15 @@ bool view_battery(void)
                 snprintf(buf, 30, "Charger: %s", 
                          charger_inserted() ? "present" : "absent");
                 lcd_puts(0, 3, buf);
+#endif
 #ifdef HAVE_CHARGE_CTRL
                 snprintf(buf, 30, "Charging: %s", 
                          charger_enabled ? "yes" : "no");
                 lcd_puts(0, 4, buf);
-#endif                
-#endif
-                y = ( power_history[POWER_HISTORY_LEN-1] * 100
-                    + power_history[POWER_HISTORY_LEN-2] * 100
-                    - power_history[POWER_HISTORY_LEN-1-CHARGE_END_NEGD+1] * 100
-                    - power_history[POWER_HISTORY_LEN-1-CHARGE_END_NEGD] * 100 )
-                    / CHARGE_END_NEGD / 2;
-                
-                snprintf(buf, 30, "short delta: %d", y);
+                snprintf(buf, 30, "short delta: %d", short_delta);
                 lcd_puts(0, 5, buf);
-                
-                y = ( power_history[POWER_HISTORY_LEN-1] * 100
-                    + power_history[POWER_HISTORY_LEN-2] * 100
-                    - power_history[POWER_HISTORY_LEN-1-CHARGE_END_ZEROD+1] * 100
-                    - power_history[POWER_HISTORY_LEN-1-CHARGE_END_ZEROD] * 100 )
-                    / CHARGE_END_ZEROD / 2;
-                
-                snprintf(buf, 30, "long delta: %d", y);
+                snprintf(buf, 30, "long delta: %d", long_delta);
                 lcd_puts(0, 6, buf);
-
-#ifdef HAVE_CHARGE_CTRL
                 lcd_puts(0, 7, power_message);
 #endif
                 break;
@@ -1069,8 +1055,7 @@ bool view_battery(void)
                 lcd_puts(0, 0, "Voltage deltas:");
                 
                 for (i = 0; i <= 6; i++) {
-                    y = power_history[POWER_HISTORY_LEN-1-i] - 
-                        power_history[POWER_HISTORY_LEN-1-i-1];
+                    y = power_history[i] - power_history[i+i];
                     snprintf(buf, 30, "-%d min: %s%d.%02d V", i,
                              (y < 0) ? "-" : "", ((y < 0) ? y * -1 : y) / 100, 
                              ((y < 0) ? y * -1 : y ) % 100);
@@ -1088,19 +1073,19 @@ bool view_battery(void)
                 snprintf(buf, 30, "Cycle time: %d m", powermgmt_last_cycle_startstop_min);
                 lcd_puts(0, 1, buf);
 
-                snprintf(buf, 30, "Lev.at cycle start: %d%%", powermgmt_last_cycle_level);
+                snprintf(buf, 30, "Lvl@cyc st: %d%%", powermgmt_last_cycle_level);
                 lcd_puts(0, 2, buf);
 #endif
 
-                snprintf(buf, 30, "Last PwrHist val: %d.%02d V",
-                    power_history[POWER_HISTORY_LEN-1] / 100,
-                    power_history[POWER_HISTORY_LEN-1] % 100);
+                snprintf(buf, 30, "Last PwrHist: %d.%02d V",
+                    power_history[0] / 100,
+                    power_history[0] % 100);
                 lcd_puts(0, 3, buf);
 
                 snprintf(buf, 30, "battery level: %d%%", battery_level());
                 lcd_puts(0, 5, buf);
 
-                snprintf(buf, 30, "Est. remaining: %d m", battery_time());
+                snprintf(buf, 30, "Est. remain: %d m", battery_time());
                 lcd_puts(0, 6, buf);
 
 #ifdef HAVE_CHARGE_CTRL
diff --git a/apps/settings.c b/apps/settings.c
index 86c1178745..866f87879e 100644
--- a/apps/settings.c
+++ b/apps/settings.c
@@ -763,8 +763,7 @@ void settings_apply(void)
 
     set_poweroff_timeout(global_settings.poweroff);
 #ifdef HAVE_CHARGE_CTRL
-    charge_restart_level = global_settings.discharge ? 
-        CHARGE_RESTART_LO : CHARGE_RESTART_HI;
+    enable_deep_discharge(global_settings.discharge);
     enable_trickle_charge(global_settings.trickle_charge);
 #endif
 
diff --git a/apps/settings_menu.c b/apps/settings_menu.c
index b19f2eda3c..4d164180dc 100644
--- a/apps/settings_menu.c
+++ b/apps/settings_menu.c
@@ -727,8 +727,7 @@ static bool deep_discharge(void)
 {
     bool result;
     result = set_bool( str(LANG_DISCHARGE), &global_settings.discharge );
-    charge_restart_level = global_settings.discharge ? 
-        CHARGE_RESTART_LO : CHARGE_RESTART_HI;
+    enable_deep_discharge(global_settings.discharge);
     return result;
 }
 static bool trickle_charge(void)
diff --git a/docs/CHARGING_ALGORITHM b/docs/CHARGING_ALGORITHM
index a1a6e2b56e..4a89cac149 100755
--- a/docs/CHARGING_ALGORITHM
+++ b/docs/CHARGING_ALGORITHM
@@ -8,12 +8,13 @@ miss some information here, write to mail@uwe-freese.de.
 
 [INTRODUCTION]
 
-This doc describes how the charging works for the recorder. The algorithm can
-be found in firmware/powermgmt.[c|h]. Debug output is done in
- apps/debug_menu.c. 
-Charging for the player and the FM/V2 recorder is done by the hardware and 
-therefore isn't implemented in rockbox. Only the functions that calculate the 
-battery level are also used for these models.
+This doc describes how the charging works for the recorder. The algorithm
+can be found in firmware/powermgmt.[c|h]. Debug output is done in
+apps/debug_menu.c.
+
+Charging for the player and the FM/V2 recorder is done by the hardware and
+therefore isn't implemented in rockbox. Only the functions that
+calculate the battery level are also used for these models.
 
 All following information is related to the recorder.
 
@@ -38,15 +39,13 @@ voltage. Both voltage curves (charging and decharging) are used here.
 [CHARGE OVERVIEW]
 
 - If voltage drops under a certain value (with "deep discharge" option on the 
-  value is lower), charging is started.
+  value is a lot lower), charging is started.
 - If end of charge is detected, go to top off charge.
 - Make the batteries completely full. 90 minutes of top off charge (voltage
-  regulation at a high value).
-- After that, do trickle charge (max. 12 hours with voltage regulation at a 
-  lower value).
-- When trickle charge is done and you did not disconnect or shut off your AJB
-  by  now, the AJB decharges normally since it reaches a low voltage and
-  everything starts from the beginning.
+  regulation at a higher value).
+- After that, trickle charge (voltage regulation at a nominal battery value).
+  The trickle charge will continue as long as the charger is plugged in (this
+  is a change from the original charge algorithm).
 
 
 [NORMAL CHARGE]
@@ -89,7 +88,7 @@ Two facts on batteries are the reason why this works:
   goes down when the temperature goes up.
 
 NiMH batteries have a smaller delta peak than NiCd, but is is enough for
-Rockbox to detect that the batteries are full.
+Rockbox to detect that the batteries are full (in theory :-).
 
 Related documents on the web:
 
@@ -114,20 +113,33 @@ It goes on again and then the archos firmware charger code would charge again.
 So we have trickle charge in rockbox.
 
 In simple words, rockbox charges about 15 seconds per minute in trickle mode.
-An AJB consumes 100 mA when it's on and the charging current is about 300mA.
+An AJB consumes 100 mA when it's on and the charging current is about 350mA.
 So charging 15 s and decharge 45 s will keep the batteries full.
 
-But the number of seconds the charger is on in trickle charge mode is also 
-adjusted dynamically (between 1 and 24 sec). Rockbox tries to hold the battery 
-level at 5,65 V (top off charge, that means "make the batteries completely 
-full") for 90 minutes, then a level of 5,45 V. If the voltage drops below the 
-wanted value, rockbox will charge one second more the next minute. If is is 
-greater than this value, is will charge one second less.
-
-Trickle charging runs 12 hours after finishing the normal charging. That
-should be enough for charging the AJB over night and then unplug the charger
-sometime in this 12 hour trickle charge time. It is not recommended to trickle
-charge over days, that's because it is stopped after 12 hours.
+But the number of seconds the charger is on in trickle charge mode is
+also adjusted dynamically. Rockbox tries to hold the battery level at
+5,65 V (top off charge, that means "make the batteries completely full")
+for 90 minutes, then a level of 5,45 V. If the voltage drops below the
+desired value, rockbox will charge one second more the next minute. If
+is is greater than this value, is will charge one second less.
+
+The number of seconds the charger is on in top off and trickle charge
+modes is also dependant on the charger's output voltage: if the charger
+supplies less than about 10v, the current into the batteries is less and
+thus the percentage on is increased to maintain the proper current into
+the batteries.
+
+The original recharging algorithm stopped trickle charging after 12 hours,
+at which time the battery would be discharged until the the batteries
+fell below the "start charging" level.  At that time the charge cycle
+would be repeated.
+
+The time limit was removed by Jerry Van Baren (along with other changes)
+in the February, 2005 timeframe.  The rationale for this is that the
+trickle charge level is very low.  In addition, it is disconcerting to
+have a AJR plugged in and "recharged" only to find out that the battery
+is only 86% full.  This was giving the Rockbox recharging algorithm a
+bad name and frustrating our users.
 
 Many chargers do top off and trickle charge by feeding a constant (low)
 current to the batteries. Rockbox, as described, makes a voltage regulation.
@@ -177,25 +189,23 @@ because it uses the raw voltages):
   always set the battery level to 100%
 - the battery level is only allowed to change 1% per minute (exception: when
   usb is connected, it is allowed to go 3% down/min)
-- if charging just started (or stopped), ignore the battery voltage for the 
-  first 25 minutes
 - after turning on the device, add another 5% to the battery level, because
   the drive is used heavily when booting and the voltage usually gets a
-  little higher after that
+  little higher after that (rebounds)
 
 
 [WHICH CHARGING MODE TO USE]
 
-If you use your AJB connected to the power supply the whole time, select "deep 
-discharge on" and "trickle charge off".
+Jerry Van Baren's revised recommendation: Select "deep discharge OFF"
+and "trickle charge ON".  This will keep your batteries charged up and
+IMHO will not damage them.
 
-If you want to charge your AJB over night and take it with you the next day, 
-select "deep discharge off" (that it starts charging immediately) and "trickle 
-charge on" (that the batteries remain full).
+Original recommendation:
 
-A special case: If you fill up the batteries that are still nearly full every 
+A special case: If you use your AJR connected to the power supply all
+the time or if you fill up the batteries that are still nearly full every
 night, it is recommended that you make a complete charge cycle from time to 
-time. Select "deep discharge on" and "trickle charge on" and wait till the
+time. Select "deep discharge ON" and "trickle charge OFF" and wait till the
 whole cycle is over (you can speed up the discharging a little bit by turning
 on the LED backlight). Even if the battery sellers say NiMH cells don't show a
 memory effect, I recommend making this procedure from time to time (every 10th
diff --git a/firmware/export/adc.h b/firmware/export/adc.h
index a18cb1995a..40bc3e108a 100644
--- a/firmware/export/adc.h
+++ b/firmware/export/adc.h
@@ -63,7 +63,7 @@
 #define ADC_BUTTON_ROW2         5 /* Used for scanning the keys, different
                                      voltages for different keys */
 #define ADC_UNREG_POWER         6 /* Battery voltage with a better scaling */
-#define ADC_EXT_POWER           7 /* The external power voltage, V=X*0.0148 */
+#define ADC_EXT_POWER           7 /* The external power voltage, 0v or 2.7v */
 
 #endif
 
diff --git a/firmware/export/powermgmt.h b/firmware/export/powermgmt.h
index 922630097a..59f9465d49 100644
--- a/firmware/export/powermgmt.h
+++ b/firmware/export/powermgmt.h
@@ -48,13 +48,12 @@
 #define BATTERY_RANGE (BATTERY_LEVEL_FULL - BATTERY_LEVEL_EMPTY)
 
 #define POWER_HISTORY_LEN 2*60   /* 2 hours of samples, one per minute */
-#define POWER_AVG_N       4      /* how many samples to take for each measurement */
-#define POWER_AVG_SLEEP   9      /* how long do we sleep between each measurement */
 
 #define CHARGE_END_NEGD   6      /* stop when N minutes have passed with
                                   * avg delta being < -0.05 V */
 #define CHARGE_END_ZEROD  50     /* stop when N minutes have passed with
                                   * avg delta being < 0.005 V */
+
 #ifndef SIMULATOR
 
 #ifdef HAVE_CHARGE_CTRL
@@ -65,27 +64,40 @@
 #define CHARGE_RESTART_HI 85     /* %: when to restart charging in 'charge' mode */
                                  /* attention: if set too high, normal charging is started in trickle mode */
 #define CHARGE_RESTART_LO 10     /* %: when to restart charging in 'discharge' mode */
-#define CHARGE_PAUSE_LEN  60     /* how many minutes to pause between charging cycles */
 #define TOPOFF_MAX_TIME   90     /* After charging, go to top off charge. How long should top off charge be? */
 #define TOPOFF_VOLTAGE    565    /* which voltage is best? (centivolts) */
 #define TRICKLE_MAX_TIME  12*60  /* After top off charge, go to trickle charge. How long should trickle charge be? */
 #define TRICKLE_VOLTAGE   545    /* which voltage is best? (centivolts) */
 
+#define START_TOPOFF_SEC    25   /* initial trickle_sec for topoff */
+#define START_TRICKLE_SEC   15   /* initial trickle_sec for trickle */
+
 extern char power_message[POWER_MESSAGE_LEN];
-extern char charge_restart_level;
+
+extern int long_delta;          /* long term delta battery voltage */
+extern int short_delta;         /* short term delta battery voltage */
 
 extern int powermgmt_last_cycle_startstop_min; /* how many minutes ago was the charging started or stopped? */
 extern int powermgmt_last_cycle_level;         /* which level had the batteries at this time? */
 
-extern int battery_lazyness[20]; /* how does the battery react when plugging in/out the charger */
+void enable_deep_discharge(bool on);    /* deep discharge the battery */
+
 void enable_trickle_charge(bool on);
 extern int trickle_sec;          /* trickle charge: How many seconds per minute are we charging actually? */
 
 #endif /* HAVE_CHARGE_CTRL */
 
-#if defined(HAVE_CHARGE_CTRL) || CONFIG_BATTERY == BATT_LIION2200
-extern int charge_state;         /* tells what the charger is doing (for info display): 0: decharging/charger off, 1: charge, 2: top-off, 3: trickle */
-#endif
+#if defined(HAVE_CHARGE_CTRL) || (CONFIG_BATTERY == BATT_LIION2200)
+typedef enum {
+    DISCHARGING,
+    CHARGING,
+    TOPOFF,
+    TRICKLE
+} charge_state_type;
+
+/* tells what the charger is doing */
+extern charge_state_type charge_state;
+#endif /* defined(HAVE_CHARGE_CTRL) || (CONFIG_BATTERY == BATT_LIION2200) */
 
 #ifdef HAVE_MMC  /* Values for Ondio */
 #define CURRENT_NORMAL     95  /* average, nearly proportional to 1/U */
@@ -95,9 +107,14 @@ extern int charge_state;         /* tells what the charger is doing (for info di
 #define CURRENT_NORMAL    145  /* usual current in mA when using the AJB including some disk/backlight/... activity */
 #define CURRENT_USB       500  /* usual current in mA in USB mode */
 #define CURRENT_BACKLIGHT  30  /* additional current when backlight is always on */
-#define CURRENT_CHARGING  300  /* charging current */
-#endif
 
+#define CURRENT_MIN_CHG    70  /* minimum charge current */
+#define MIN_CHG_V        8500  /* at 8.5v charger voltage get CURRENT_MIN_CHG */
+#define CURRENT_MAX_CHG   350  /* maximum charging current */
+#define MAX_CHG_V       10250  /* anything over 10.25v gives CURRENT_MAX_CHG */
+#endif /* HAVE_MMC */
+
+extern unsigned int bat;       /* filtered battery voltage, centivolts */
 extern unsigned short power_history[POWER_HISTORY_LEN];
 
 /* Start up power management thread */
@@ -114,7 +131,7 @@ bool battery_level_safe(void);
 
 void set_poweroff_timeout(int timeout);
 void set_battery_capacity(int capacity); /* set local battery capacity value */
-void set_battery_type(int type); /* set local battery type */
+void set_battery_type(int type);         /* set local battery type */
 
 void set_sleep_timer(int seconds);
 int get_sleep_timer(void);
diff --git a/firmware/powermgmt.c b/firmware/powermgmt.c
index 2a15b9dfb4..0db2f03a7b 100644
--- a/firmware/powermgmt.c
+++ b/firmware/powermgmt.c
@@ -8,6 +8,7 @@
  * $Id$
  *
  * Copyright (C) 2002 by Heikki Hannikainen, Uwe Freese
+ * Revisions copyright (C) 2005 by Gerald Van Baren
  *
  * All files in this archive are subject to the GNU General Public License.
  * See the file COPYING in the source tree root for full license agreement.
@@ -41,6 +42,22 @@
 #include "fmradio.h"
 #endif
 
+/*
+ * Define DEBUG_FILE to create a csv (spreadsheet) with battery information
+ * in it (one sample per minute).  This is only for very low level debug.
+ */
+#undef  DEBUG_FILE
+#if defined(DEBUG_FILE) && defined(HAVE_CHARGE_CTRL)
+#include "file.h"
+#define DEBUG_FILE_NAME   "/powermgmt.csv"
+#define DEBUG_MESSAGE_LEN 133
+static char debug_message[DEBUG_MESSAGE_LEN];
+#define DEBUG_STACK ((0x1000)/sizeof(long))
+static int fd;          /* write debug information to this file */
+#else
+#define DEBUG_STACK 0
+#endif
+
 long last_event_tick;
 
 void reset_poweroff_timer(void)
@@ -48,7 +65,7 @@ void reset_poweroff_timer(void)
     last_event_tick = current_tick;
 }
 
-#ifdef SIMULATOR
+#ifdef SIMULATOR /***********************************************************/
 
 int battery_level(void)
 {
@@ -80,19 +97,14 @@ void set_car_adapter_mode(bool setting)
     (void)setting;
 }
 
-#else /* not SIMULATOR */
-
-int battery_capacity = BATTERY_CAPACITY_MIN; /* only a default value */
-int battery_level_cached = -1; /* battery level of this minute, updated once
-                                  per minute */
-static bool car_adapter_mode_enabled = false;
+#else /* not SIMULATOR ******************************************************/
 
 static const int poweroff_idle_timeout_value[15] =
 {
     0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 30, 45, 60
 };
 
-static const short percent_to_volt_decharge[BATTERY_TYPES_COUNT][11] =
+static const short percent_to_volt_discharge[BATTERY_TYPES_COUNT][11] =
 /* voltages (centivolt) of 0%, 10%, ... 100% when charging disabled */
 {
 #if CONFIG_BATTERY == BATT_LIION2200
@@ -110,50 +122,44 @@ static const short percent_to_volt_decharge[BATTERY_TYPES_COUNT][11] =
 #endif
 };
 
-void set_battery_capacity(int capacity)
-{
-    battery_capacity = capacity;
-    if (battery_capacity > BATTERY_CAPACITY_MAX)
-        battery_capacity = BATTERY_CAPACITY_MAX;
-    if (battery_capacity < BATTERY_CAPACITY_MIN)
-        battery_capacity = BATTERY_CAPACITY_MIN;
-}
-
-#if BATTERY_TYPES_COUNT > 1
 static int battery_type = 0;
 
-void set_battery_type(int type)
-{
-    if (type != battery_type) {
-        battery_type = type;
-        battery_level_cached = -1; /* reset on type change */
-    }
-}
+#if defined(HAVE_CHARGE_CTRL) || CONFIG_BATTERY == BATT_LIION2200
+charge_state_type charge_state;     /* charging mode */
+int  charge_timer;                  /* charge timer (minutes, dec to zero) */
 #endif
 
-#if defined(HAVE_CHARGE_CTRL) || CONFIG_BATTERY == BATT_LIION2200
-int charge_state = 0;                          /* at the beginning, the
-                                                  charger does nothing */
+#ifdef HAVE_CHARGING
+/* Flag that the charger has been plugged in */
+static bool charger_was_inserted = false;   /* for power off logic */
+static bool charger_power_is_on;            /* for car adapter mode */
 #endif
 
+/* Power history: power_history[0] is the newest sample */
+unsigned short power_history[POWER_HISTORY_LEN];
+
 #ifdef HAVE_CHARGE_CTRL
 
+int long_delta;                     /* long term delta battery voltage */
+int short_delta;                    /* short term delta battery voltage */
+
 char power_message[POWER_MESSAGE_LEN] = "";    /* message that's shown in
                                                   debug menu */
-char charge_restart_level = CHARGE_RESTART_HI; /* level at which charging
+static char charge_restart_level = CHARGE_RESTART_HI;
+                                               /* percentage at which charging
                                                   starts */
-int powermgmt_last_cycle_startstop_min = 25;   /* how many minutes ago was the
+int powermgmt_last_cycle_startstop_min = 0;    /* how many minutes ago was the
                                                   charging started or
                                                   stopped? */
 int powermgmt_last_cycle_level = 0;            /* which level had the
                                                   batteries at this time? */
 bool trickle_charge_enabled = true;
-int trickle_sec = 0;                           /* how many seconds should the
+int  trickle_sec = 0;                          /* how many seconds should the
                                                   charger be enabled per
                                                   minute for trickle
                                                   charging? */
-static const short percent_to_volt_charge[11] =
 /* voltages (centivolt) of 0%, 10%, ... 100% when charging enabled */
+static const short percent_to_volt_charge[11] =
 {
     /* values guessed, see
        http://www.seattlerobotics.org/encoder/200210/LiIon2.pdf until someone
@@ -161,23 +167,64 @@ static const short percent_to_volt_charge[11] =
     476, 544, 551, 556, 561, 564, 566, 576, 582, 584, 585 /* NiMH */
 };
 
-void enable_trickle_charge(bool on)
-{
-    trickle_charge_enabled = on;
-}
-#endif /* HAVE_CHARGE_CTRL */
+#endif /* HAVE_CHARGE_CTRL || CONFIG_BATTERY == BATT_LIION2200 */
+
+/*
+ * Average battery voltage and charger voltage, filtered via a digital
+ * exponential filter.
+ */
+unsigned int battery_centivolts;/* filtered battery voltage, centvolts */
+static unsigned int avgbat;     /* average battery voltage */
+#define BATT_AVE_SAMPLES	32  /* filter constant / @ 2Hz sample rate */
+
+int battery_capacity = BATTERY_CAPACITY_MIN; /* only a default value */
 
-static long power_stack[DEFAULT_STACK_SIZE/sizeof(long)];
+/* battery level (0-100%) of this minute, updated once per minute */
+static int battery_percent = -1;
+
+static bool car_adapter_mode_enabled = false;
+
+static char power_stack[DEFAULT_STACK_SIZE + DEBUG_STACK];
 static const char power_thread_name[] = "power";
 
-static int poweroff_timeout = 0;
+static int  poweroff_timeout = 0;
 static long last_charge_time = 0;
 int powermgmt_est_runningtime_min = -1;
 
 static bool sleeptimer_active = false;
 static unsigned long sleeptimer_endtick;
 
-unsigned short power_history[POWER_HISTORY_LEN];
+#ifdef HAVE_CHARGE_CTRL
+
+void enable_deep_discharge(bool on)
+{
+    charge_restart_level = on ? CHARGE_RESTART_LO : CHARGE_RESTART_HI;
+}
+
+void enable_trickle_charge(bool on)
+{
+    trickle_charge_enabled = on;
+}
+#endif /* HAVE_CHARGE_CTRL */
+
+#if BATTERY_TYPES_COUNT > 1
+void set_battery_type(int type)
+{
+    if (type != battery_type) {
+        battery_type = type;
+        battery_percent = -1; /* reset on type change */
+    }
+}
+#endif
+
+void set_battery_capacity(int capacity)
+{
+    battery_capacity = capacity;
+    if (battery_capacity > BATTERY_CAPACITY_MAX)
+        battery_capacity = BATTERY_CAPACITY_MAX;
+    if (battery_capacity < BATTERY_CAPACITY_MIN)
+        battery_capacity = BATTERY_CAPACITY_MIN;
+}
 
 int battery_time(void)
 {
@@ -208,23 +255,9 @@ int voltage_to_percent(int voltage, const short* table)
 /* update battery level, called only once per minute */
 void battery_level_update(void)
 {
-    int level = 0;
-    unsigned short c = 0;
-    int i;
-#if BATTERY_TYPES_COUNT == 1 /* single type */
-    const int battery_type = 0;
-#endif
-    
-    /* calculate maximum over last 3 minutes (skip empty samples) */
-    for (i = 0; i < 3; i++)
-        if (power_history[POWER_HISTORY_LEN-1-i] > c)
-            c = power_history[POWER_HISTORY_LEN-1-i];
-        
-    if (c)
-        level = c;
-    else /* history was empty, get a fresh sample */
-        level = (adc_read(ADC_UNREG_POWER) * BATTERY_SCALE_FACTOR) / 10000;
+    int level;
 
+    level = battery_centivolts;
     if(level > BATTERY_LEVEL_FULL)
         level = BATTERY_LEVEL_FULL;
 
@@ -232,27 +265,27 @@ void battery_level_update(void)
         level = BATTERY_LEVEL_EMPTY;
 
 #ifdef HAVE_CHARGE_CTRL
-    if (charge_state == 0) { /* decharge */
+    if (charge_state == DISCHARGING) {
         level = voltage_to_percent(level, 
-                percent_to_volt_decharge[battery_type]);
+                percent_to_volt_discharge[battery_type]);
     }
-    else if (charge_state == 1) { /* charge */
+    else if (charge_state == CHARGING) {
         level = voltage_to_percent(level, percent_to_volt_charge);
     }
-    else {/* in trickle charge, the battery is per definition 100% full */
-        battery_level_cached = level = 100;
+    else {/* in trickle charge, the battery is by definition 100% full */
+        battery_percent = level = 100;
     }
 #else
+    /* always use the discharge table */
     level = voltage_to_percent(level,
-            percent_to_volt_decharge[battery_type]);
-    /* always use the decharge table */
+            percent_to_volt_discharge[battery_type]);
 #endif
 
 #ifndef HAVE_MMC  /* this adjustment is only needed for HD based */
-    if (battery_level_cached == -1) { /* first run of this procedure */
-        /* the battery voltage is usually a little lower directly after
-           turning on, because the disk was used heavily raise it by 5 % */
-        battery_level_cached = (level > 95) ? 100 : level + 5;
+    if (battery_percent == -1) { /* first run of this procedure */
+        /* The battery voltage is usually a little lower directly after
+           turning on, because the disk was used heavily. Raise it by 5. % */
+        battery_percent = (level > 95) ? 100 : level + 5;
     }
     else 
 #endif
@@ -260,14 +293,14 @@ void battery_level_update(void)
         /* the level is allowed to be -1 of the last value when usb not
            connected and to be -3 of the last value when usb is connected */
         if (usb_inserted()) {
-            if (level < battery_level_cached - 3)
-                level = battery_level_cached - 3;
+            if (level < battery_percent - 3)
+                level = battery_percent - 3;
         }
         else {
-            if (level < battery_level_cached - 1)
-                level = battery_level_cached - 1;
+            if (level < battery_percent - 1)
+                level = battery_percent - 1;
         }
-        battery_level_cached = level;
+        battery_percent = level;
     }
 }
 
@@ -275,21 +308,16 @@ void battery_level_update(void)
 int battery_level(void)
 {
 #ifdef HAVE_CHARGE_CTRL
-    if ((charge_state==1) && (battery_level_cached==100))
+    if ((charge_state == CHARGING) && (battery_percent == 100))
         return 99;
 #endif
-    return battery_level_cached;
+    return battery_percent;
 }
 
 /* Tells if the battery level is safe for disk writes */
 bool battery_level_safe(void)
 {
-    /* I'm pretty sure we don't want an average over a long time here */
-    if (power_history[POWER_HISTORY_LEN-1])
-        return power_history[POWER_HISTORY_LEN-1] > BATTERY_LEVEL_DANGEROUS;
-    else
-        return adc_read(ADC_UNREG_POWER) > (BATTERY_LEVEL_DANGEROUS * 10000L) /
-            BATTERY_SCALE_FACTOR;
+    return battery_centivolts > BATTERY_LEVEL_DANGEROUS;
 }
 
 void set_poweroff_timeout(int timeout)
@@ -329,10 +357,12 @@ int get_sleep_timer(void)
 static void handle_auto_poweroff(void)
 {
     long timeout = poweroff_idle_timeout_value[poweroff_timeout]*60*HZ;
-    int mpeg_stat = mpeg_status();
+    int  mpeg_stat = mpeg_status();
+#ifdef HAVE_CHARGING
     bool charger_is_inserted = charger_inserted();
-    static bool charger_was_inserted = false;
+#endif
 
+#ifdef HAVE_CHARGING
     /* The was_inserted thing prevents the unit to shut down immediately
        when the charger is extracted */
     if(charger_is_inserted || charger_was_inserted)
@@ -340,13 +370,14 @@ static void handle_auto_poweroff(void)
         last_charge_time = current_tick;
     }
     charger_was_inserted = charger_is_inserted;
+#endif
     
     if(timeout &&
 #ifdef CONFIG_TUNER
        (radio_get_status() != FMRADIO_PLAYING) &&
 #endif
        !usb_inserted() &&
-       (mpeg_stat == 0 ||
+       ((mpeg_stat == 0) ||
         ((mpeg_stat == (MPEG_STATUS_PLAY | MPEG_STATUS_PAUSE)) &&
          !sleeptimer_active)))
     {
@@ -365,6 +396,7 @@ static void handle_auto_poweroff(void)
             if(TIME_AFTER(current_tick, sleeptimer_endtick))
             {
                 mpeg_stop();
+#ifdef HAVE_CHARGING
                 if(charger_is_inserted)
                 {
                     DEBUGF("Sleep timer timeout. Stopping...\n");
@@ -372,6 +404,7 @@ static void handle_auto_poweroff(void)
                     backlight_off(); /* Nighty, nighty... */
                 }
                 else
+#endif
                 {
                     DEBUGF("Sleep timer timeout. Shutting off...\n");
                     /* Make sure that the disk isn't spinning when
@@ -390,8 +423,6 @@ void set_car_adapter_mode(bool setting)
     car_adapter_mode_enabled = setting;
 }
 
-static bool charger_power_is_on;
-
 #ifdef HAVE_CHARGING
 static void car_adapter_mode_processing(void)
 {
@@ -442,13 +473,38 @@ static void car_adapter_mode_processing(void)
 }
 #endif
 
+/*
+ * Estimate how much current we are drawing just to run.
+ */
+static int runcurrent(void)
+{
+    int current;
+
+    current = CURRENT_NORMAL;
+    if(usb_inserted()) {
+        current = CURRENT_USB;
+    }
+#ifdef HAVE_CHARGE_CTRL
+    if ((backlight_get_timeout() == 1) || /* LED always on */
+        (charger_inserted() && backlight_get_on_when_charging())) {
+        current += CURRENT_BACKLIGHT;
+    }
+#else
+    if (backlight_get_timeout() == 1) { /* LED always on */
+        current += CURRENT_BACKLIGHT;
+    }
+#endif
+
+    return(current);
+}
+
+
 /* Check to see whether or not we've received an alarm in the last second */
 #ifdef HAVE_ALARM_MOD
 static void power_thread_rtc_process(void) 
 {
-
     if (rtc_check_alarm_flag()) {
-	rtc_enable_alarm(false);
+        rtc_enable_alarm(false);
     }
 }
 #endif
@@ -457,24 +513,56 @@ static void power_thread_rtc_process(void)
  * This function is called to do the relativly long sleep waits from within the
  * main power_thread loop while at the same time servicing any other periodic
  * functions in the power thread which need to be called at a faster periodic
- * rate than the slow periodic rate of the main power_thread loop
+ * rate than the slow periodic rate of the main power_thread loop.
+ *
+ * While we are waiting for the time to expire, we average the battery
+ * voltages.
  */
 static void power_thread_sleep(int ticks)
 {
+    int small_ticks;
 #ifdef HAVE_CHARGING
+    unsigned int tmp;
+    bool charger_plugged;
+#endif
+
+#ifdef HAVE_CHARGING
+    charger_plugged = charger_inserted();
+#endif
     while (ticks > 0) {
-        int small_ticks = MIN(HZ/2, ticks);
+        small_ticks = MIN(HZ/2, ticks);
         sleep(small_ticks);
         ticks -= small_ticks;
 
+#ifdef HAVE_CHARGING
         car_adapter_mode_processing();
+#endif
 #ifdef HAVE_ALARM_MOD
-	power_thread_rtc_process();
+        power_thread_rtc_process();
 #endif
-    }
-#else
-    sleep(ticks);  /* no fast-processing functions, sleep the whole time */
+
+        /*
+         * Do a digital exponential filter.  We don't sample the battery if
+         * the disk is spinning unless we are in USB mode (the disk will most
+         * likely always be spinning in USB mode).
+         * If the charging voltage is greater than 0x3F0 charging isn't active
+         * and that voltage isn't valid.
+         */
+        if (!ata_disk_is_active() || usb_inserted()) {
+            avgbat = avgbat - (avgbat / BATT_AVE_SAMPLES) +
+                     adc_read(ADC_UNREG_POWER);
+            /*
+             * battery_centivolts is the centivolt-scaled filtered battery value.
+             */
+            battery_centivolts = ((avgbat / BATT_AVE_SAMPLES) * BATTERY_SCALE_FACTOR) / 10000;
+        }
+
+#ifdef HAVE_CHARGING
+        /* If the charger was plugged in, exit now so we can start charging */
+        if(!charger_plugged && charger_inserted())
+            return;
 #endif
+    }
 }
 
 
@@ -488,102 +576,60 @@ static void power_thread_sleep(int ticks)
 static void power_thread(void)
 {
     int i;
-    int avg, ok_samples, spin_samples;
-    int current = 0;
+    short *phps, *phpd;         /* power history rotation pointers */
 #if CONFIG_BATTERY == BATT_LIION2200
     int charging_current;
 #endif
 #ifdef HAVE_CHARGE_CTRL
-    int delta;
-    int charged_time = 0;
     int charge_max_time_now = 0;  /* max. charging duration, calculated at
                                      beginning of charging */
-    int charge_pause = 0;         /* no charging pause at the beginning */
-    int trickle_time = 0;         /* how many minutes trickle charging already? */
 #endif
+
+    /* initialize the voltages for the exponential filter */
     
+    avgbat = adc_read(ADC_UNREG_POWER) * BATT_AVE_SAMPLES;
+    battery_centivolts    = ((avgbat / BATT_AVE_SAMPLES) * BATTERY_SCALE_FACTOR) / 10000;
+
+#if defined(DEBUG_FILE) && defined(HAVE_CHARGE_CTRL)
+    fd = -1;
+#endif
+            
     while (1)
     {
-        /* never read power while disk is spinning, unless in USB mode */
-        if (ata_disk_is_active() && !usb_inserted()) {
-#ifdef HAVE_ALARM_MOD
-	    power_thread_rtc_process();
-#endif
-            sleep(HZ);
-            continue;
-        }
-        
-        /* Make POWER_AVG measurements and calculate an average of that to
-         * reduce the effect of backlights/disk spinning/other variation.
-         */
-        ok_samples = spin_samples = avg = 0;
-        for (i = 0; i < POWER_AVG_N; i++) {
-            if (ata_disk_is_active()) {
-                if (!ok_samples) {
-                    /* if we don't have any good non-disk-spinning samples,
-                     * we take a sample anyway in case the disk is going
-                     * to spin all the time.
-                     */
-                    avg += adc_read(ADC_UNREG_POWER);
-                    spin_samples++;
-                }
-            } else {
-                if (spin_samples) /* throw away disk-spinning samples */
-                    spin_samples = avg = 0;
-                avg += adc_read(ADC_UNREG_POWER);
-                ok_samples++;
-            }
-            power_thread_sleep(HZ*POWER_AVG_SLEEP);
-        }
-        avg = avg / ((ok_samples) ? ok_samples : spin_samples);
-
         /* rotate the power history */
+        phpd = &power_history[POWER_HISTORY_LEN - 1];
+        phps = phpd - 1;
         for (i = 0; i < POWER_HISTORY_LEN-1; i++)
-            power_history[i] = power_history[i+1];
-        
-        /* insert new value in the end, in centivolts 8-) */
-        power_history[POWER_HISTORY_LEN-1] =
-            (avg * BATTERY_SCALE_FACTOR) / 10000;
+            *phpd-- = *phps--;
         
-        /* update battery level every minute, ignoring first 15 minutes after
-           start charge/decharge */
-#ifdef HAVE_CHARGE_CTRL
-        if ((powermgmt_last_cycle_startstop_min > 25) || (charge_state > 1))
-#endif
-            battery_level_update();
+        /* insert new value at the start, in centivolts 8-) */
+        power_history[0] = battery_centivolts;
+
+        /* update battery level every minute */
+        battery_level_update();
 
         /* calculate estimated remaining running time */
-        /* decharging: remaining running time */
-        /* charging:   remaining charging time */
+        /* discharging: remaining running time */
+        /* charging:    remaining charging time */
 
-#ifdef HAVE_CHARGE_CTRL
-        if (charge_state == 1)
-            powermgmt_est_runningtime_min = (100 - battery_level()) *
-                battery_capacity / 100 * 60 / CURRENT_CHARGING;
-        else {
-            current = usb_inserted() ? CURRENT_USB : CURRENT_NORMAL;
-            if ((backlight_get_timeout() == 1) ||
-                (charger_inserted() && backlight_get_on_when_charging()))
-                /* LED always on or LED on when charger connected */
-                current += CURRENT_BACKLIGHT;
-            powermgmt_est_runningtime_min = battery_level() *
-                battery_capacity / 100 * 60 / current;
-#if MEM == 8 /* assuming 192 kbps, the running time is 22% longer with 8MB */
-            powermgmt_est_runningtime_min =
-                powermgmt_est_runningtime_min * 122 / 100;
-#endif /* MEM == 8 */
-        }
-#else
-        current = usb_inserted() ? CURRENT_USB : CURRENT_NORMAL;
-        if (backlight_get_timeout() == 1) /* LED always on */
-            current += CURRENT_BACKLIGHT;
         powermgmt_est_runningtime_min = battery_level() *
-            battery_capacity / 100 * 60 / current;
+            battery_capacity / 100 * 60 / runcurrent();
 #if MEM == 8 /* assuming 192 kbps, the running time is 22% longer with 8MB */
         powermgmt_est_runningtime_min =
             powermgmt_est_runningtime_min * 122 / 100;
 #endif /* MEM == 8 */
-#endif /* HAVE_CHARGE_CONTROL */
+
+#ifdef HAVE_CHARGE_CTRL
+        /*
+         * If we are charging, the "runtime" is estimated time till the battery
+         * is recharged.
+         */
+        // TBD: use real charging current estimate
+        if (charge_state == CHARGING) {
+            powermgmt_est_runningtime_min = (100 - battery_level()) *
+                 battery_capacity / 100 * 60 / (CURRENT_MAX_CHG - runcurrent());
+        }
+#endif /* HAVE_CHARGE_CTRL */
 
 #if CONFIG_BATTERY == BATT_LIION2200
         /* We use the information from the ADC_EXT_POWER ADC channel, which
@@ -595,262 +641,235 @@ static void power_thread(void)
         if(charger_inserted()) {
             charging_current = adc_read(ADC_EXT_POWER);
             if(charging_current < 0x80) {
-                charge_state = 2; /* Trickle */
+                charge_state = TRICKLE;
             } else {
-                charge_state = 1; /* Charging */
+                charge_state = CHARGING;
             }
         } else {
-            charge_state = 0; /* Not charging */
+            charge_state = DISCHARGING;
         }
-#else
+#endif /* # if CONFIG_BATTERY == BATT_LIION2200 */
+
 #ifdef HAVE_CHARGE_CTRL
 
-        if (charge_pause > 0)
-            charge_pause--;
-        
         if (charger_inserted()) {
-            if (charge_state == 1) {
-                /* charger inserted and enabled */
-                charged_time++;
-                snprintf(power_message, POWER_MESSAGE_LEN,
-                         "Chg %dm max %dm", charged_time, charge_max_time_now);
-
-                if (charged_time > charge_max_time_now) {
-                    DEBUGF("power: charged_time > charge_max_time_now, "
-                           "enough!\n");
-                    /* have charged too long and deltaV detection did not
-                       work! */
-                    powermgmt_last_cycle_level = battery_level();
+            /*
+             * Time to start charging again?
+             * 1) If we are currently discharging but trickle is enabled,
+             *    the charger must have just been plugged in.
+             * 2) If our battery level falls below the restart level, charge!
+             */
+            if (((charge_state == DISCHARGING) && trickle_charge_enabled) ||
+                (battery_level() < charge_restart_level)) {
+
+                /*
+                 * If the battery level is nearly charged, just trickle.
+                 * If the battery is in between, top-off and then trickle.
+                 */
+                if(battery_percent > charge_restart_level) {
+                    powermgmt_last_cycle_level = battery_percent;
                     powermgmt_last_cycle_startstop_min = 0;
-                    charger_enable(false);
-                    snprintf(power_message, POWER_MESSAGE_LEN,
-                             "Chg tmout %d min", charge_max_time_now);
-                    /* disable charging for several hours from this point,
-                       just to be sure */
-                    charge_pause = CHARGE_PAUSE_LEN;
-                    /* no trickle charge here, because the charging cycle
-                       didn't end the right way */
-                    charge_state = 0; /* 0: decharging/charger off, 1: charge,
-                                         2: top-off, 3: trickle */
+                    if(battery_percent >= 95) {
+                        trickle_sec  = START_TRICKLE_SEC;
+                        charge_state = TRICKLE;
+                    } else {
+                        trickle_sec  = START_TOPOFF_SEC;
+                        charge_state = TOPOFF;
+                    }
                 } else {
-                    if (charged_time > CHARGE_MIN_TIME) {
-                        /* have charged continuously over the minimum charging
-                           time, so we monitor for deltaV going
-                           negative. Multiply thingsby 100 to get more
-                           accuracy without floating point arithmetic.
-                           power_history[] contains centivolts so after
-                           multiplying by 100 the deltas are in tenths of
-                           millivolts (delta of 5 is 0.0005 V).
-                         */
-                        delta =
-                            ( power_history[POWER_HISTORY_LEN-1] * 100
-                              + power_history[POWER_HISTORY_LEN-2] * 100
-                              - power_history[POWER_HISTORY_LEN-1-
-                                              CHARGE_END_NEGD+1] * 100
-                              - power_history[POWER_HISTORY_LEN-1-
-                                              CHARGE_END_NEGD] * 100 )
-                            / CHARGE_END_NEGD / 2;
-                        
-                        if (delta < -100) { /* delta < -10 mV */
+                    /*
+                     * Start the charger full strength
+                     */
+                    i = CHARGE_MAX_TIME_1500 * battery_capacity / 1500;
+                    charge_max_time_now =
+                        i * (100 + 35 - battery_percent) / 100;
+                    if (charge_max_time_now > i) {
+                        charge_max_time_now = i;
+                    }
+                    snprintf(power_message, POWER_MESSAGE_LEN,
+                             "ChgAt %d%% max %dm", battery_level(),
+                             charge_max_time_now);
+    
+                    /* enable the charger after the max time calc is done,
+                       because battery_level depends on if the charger is
+                       on */
+                    DEBUGF("power: charger inserted and battery"
+                           " not full, enabling\n");
+                    powermgmt_last_cycle_level = battery_percent;
+                    powermgmt_last_cycle_startstop_min = 0;
+                    trickle_sec  = 60;
+                    charge_state = CHARGING;
+                }
+            }
+            if (charge_state == CHARGING) {
+                /* charger inserted and enabled 100% of the time */
+                trickle_sec = 60; /* 100% on */
+
+                snprintf(power_message, POWER_MESSAGE_LEN,
+                         "Chg %dm, max %dm", powermgmt_last_cycle_startstop_min,
+                         charge_max_time_now);
+                /*
+                 * Sum the deltas over the last X minutes so we can do our
+                 *   end-of-charge logic based on the battery level change.
+                 */
+                long_delta = short_delta = 999999;
+                if (powermgmt_last_cycle_startstop_min > CHARGE_MIN_TIME) {
+                    short_delta = power_history[0] -
+                                  power_history[CHARGE_END_NEGD - 1];
+                }
+                if (powermgmt_last_cycle_startstop_min > CHARGE_END_ZEROD) {
+                /*
+                 * Scan the history: if we have a big delta in the middle of
+                 * our history, the long term delta isn't a valid end-of-charge
+                 * indicator.
+                 */
+                    long_delta = power_history[0] -
+                                 power_history[CHARGE_END_ZEROD - 1];
+                    for(i = 0; i < CHARGE_END_ZEROD; i++) {
+                        if(((power_history[i] - power_history[i+1]) >  5) ||
+                           ((power_history[i] - power_history[i+1]) < -5)) {
+                            long_delta = 888888;
+                            break;
+                        }
+                    }
+                }
+
+                /*
+                 * End of charge criteria (any qualify):
+                 * 1) Charged a long time
+                 * 2) DeltaV went negative for a short time
+                 * 3) DeltaV was close to zero for a long time
+                 * Note: short_delta and long_delta are centivolts
+                 */
+                if ((powermgmt_last_cycle_startstop_min > charge_max_time_now) ||
+                    (short_delta < -5) || (long_delta  <  5))
+                {
+                    if (powermgmt_last_cycle_startstop_min > charge_max_time_now) {
+                        DEBUGF("power: powermgmt_last_cycle_startstop_min > charge_max_time_now, "
+                               "enough!\n");
+                        /* have charged too long and deltaV detection did not
+                           work! */
+                        snprintf(power_message, POWER_MESSAGE_LEN,
+                                 "Chg tmout %d min", charge_max_time_now);
+                    } else {
+                        if(short_delta < -5) {
                             DEBUGF("power: short-term negative"
                                    " delta, enough!\n");
-                            powermgmt_last_cycle_level = battery_level();
-                            powermgmt_last_cycle_startstop_min = 0;
-                            charger_enable(false);
                             snprintf(power_message, POWER_MESSAGE_LEN,
-                                     "end negd %d %dmin", delta, charged_time);
-                            /* disable charging for several hours from this
-                               point, just to be sure */
-                            charge_pause = CHARGE_PAUSE_LEN;
-                            /* enable trickle charging */
-                            if (trickle_charge_enabled) {
-                                trickle_sec = CURRENT_NORMAL * 60 /
-                                    CURRENT_CHARGING;
-                                /* first guess, maybe consider if LED
-                                   backlight is on, disk is active,... */
-                                trickle_time = 0;
-                                charge_state = 2; /* 0: decharging/charger
-                                                     off, 1: charge,
-                                                     2: top-off, 3: trickle */
-                            } else {
-                                charge_state = 0; /* 0: decharging/charger
-                                                     off, 1: charge,
-                                                     2: top-off, 3: trickle */
-                            }
+                                     "end negd %d %dmin", short_delta,
+                                     powermgmt_last_cycle_startstop_min);
                         } else {
-                            /* if we didn't disable the charger in the
-                               previous test, check for low positive delta */
-                            delta =
-                                ( power_history[POWER_HISTORY_LEN-1] * 100
-                                  + power_history[POWER_HISTORY_LEN-2] * 100
-                                  - power_history[POWER_HISTORY_LEN-1-
-                                                  CHARGE_END_ZEROD+1] * 100
-                                  - power_history[POWER_HISTORY_LEN-1-
-                                                  CHARGE_END_ZEROD] * 100 )
-                                / CHARGE_END_ZEROD / 2;
-                            
-                            if (delta < 1) { /* delta < 0.1 mV */
-                                DEBUGF("power: long-term small "
-                                       "positive delta, enough!\n");
-                                powermgmt_last_cycle_level = battery_level();
-                                powermgmt_last_cycle_startstop_min = 0;
-                                charger_enable(false);
-                                snprintf(power_message, POWER_MESSAGE_LEN,
-                                         "end lowd %d %dmin",
-                                         delta, charged_time);
-                                /* disable charging for several hours from
-                                   this point, just to be sure */
-                                charge_pause = CHARGE_PAUSE_LEN;
-                                /* enable trickle charging */
-                                if (trickle_charge_enabled) {
-                                    trickle_sec =
-                                        CURRENT_NORMAL * 60 / CURRENT_CHARGING;
-                                    /* first guess, maybe consider if LED
-                                       backlight is on, disk is active,... */
-                                    trickle_time = 0;
-                                    charge_state = 2;
-                                    /* 0: decharging/charger off, 1: charge,
-                                       2: top-off, 3: trickle */
-                                } else {
-                                    charge_state = 0;
-                                    /* 0: decharging/charger off, 1: charge,
-                                       2: top-off, 3: trickle */
-                                }
-                            }
+                            DEBUGF("power: long-term small "
+                                   "positive delta, enough!\n");
+                            snprintf(power_message, POWER_MESSAGE_LEN,
+                                     "end lowd %d %dmin", long_delta,
+                                     powermgmt_last_cycle_startstop_min);
                         }
                     }
+                    /* Switch to trickle charging.  We skip the top-off
+                       since we've effectively done the top-off operation
+                       already since we charged for the maximum full
+                       charge time.  For trickle charging, we use 0.05C */
+                    powermgmt_last_cycle_level = battery_percent;
+                    powermgmt_last_cycle_startstop_min = 0;
+                    if (trickle_charge_enabled) {
+                        trickle_sec  = START_TRICKLE_SEC;
+                        charge_state = TRICKLE;
+                    } else {
+                        /* If we don't trickle charge, we discharge */
+                        trickle_sec  = 0; /* off */
+                        charge_state = DISCHARGING;
+                    }
                 }
             }
-            else if (charge_state > 1) { /* top off or trickle? */
-                /* adjust trickle charge time */
-                if (  ((charge_state == 2) &&
-                       (power_history[POWER_HISTORY_LEN-1] > TOPOFF_VOLTAGE))
-                   || ((charge_state == 3) &&
-                       (power_history[POWER_HISTORY_LEN-1] >
-                        TRICKLE_VOLTAGE)) ) { /* charging too much */
-                    trickle_sec--;
-                }
-                else { /* charging too less */
-                    trickle_sec++;
-                }
-                    
-                if (trickle_sec > 24)
-                    trickle_sec = 24;
-
-                if (trickle_sec < 1)
-                    trickle_sec = 1;
-
-                /* charge the calculated amount of seconds */                
-                charger_enable(true);
-                power_thread_sleep(HZ * trickle_sec);
-                charger_enable(false);             
-
-                /* trickle charging long enough? */
-                
-                if (trickle_time++ > TRICKLE_MAX_TIME + TOPOFF_MAX_TIME) {
-                    trickle_sec = 0; /* show in debug menu that trickle is
-                                        off */
-                    charge_state = 0; /* 0: decharging/charger off, 1: charge,
-                                         2: top-off, 3: trickle */
+            else if (charge_state > CHARGING)  /* top off or trickle */
+            {
+                /* Time to switch from topoff to trickle? Note that we don't
+                 * adjust trickle_sec: it will get adjusted down by the
+                 * charge level adjustment in the loop and will drift down
+                 * from the topoff level to the trickle level.
+                 */
+                if ((charge_state == TOPOFF) &&
+                    (powermgmt_last_cycle_startstop_min > TOPOFF_MAX_TIME))
+                {
+                    powermgmt_last_cycle_level = battery_percent;
                     powermgmt_last_cycle_startstop_min = 0;
+                    charge_state = TRICKLE;
                 }
 
-                if ((charge_state == 2) &&
-                    (trickle_time > TOPOFF_MAX_TIME)) /* change state? */
-                    charge_state = 3; /* 0: decharging/charger off, 1: charge,
-                                         2: top-off, 3: trickle */
-            
-            } else { /* charge_state == 0 */
+                /* Adjust trickle charge time.  I considered setting the level
+                 * higher if the USB is plugged in, but it doesn't appear to
+                 * be necessary and will generate more heat [gvb].
+                 */
+                if(((charge_state == TOPOFF)  && (battery_centivolts > TOPOFF_VOLTAGE)) ||
+                   ((charge_state == TRICKLE) && (battery_centivolts > TRICKLE_VOLTAGE)))
+                { /* charging too much */
+                    if(trickle_sec > 0)
+                        trickle_sec--;
+                }
+                else { /* charging too little */
+                    if(trickle_sec < 60)
+                        trickle_sec++;
+                }
 
+            } else if (charge_state == DISCHARGING) {
+                trickle_sec = 0;
                 /* the charger is enabled here only in one case: if it was
                    turned on at boot time (power_init) */
                 /* turn it off now */
                 if (charger_enabled)
                     charger_enable(false);
             }
-
-            /* Start new charge cycle? This must be possible also in
-               trickle/top-off, because when usb connected, */
-            /* the trickle charge amount may not be enough */
-            
-            if ((charge_state == 0) || (charge_state > 1))
-                /* if battery is not full, enable charging */
-                /* make sure charging starts if 1%-lazyness in
-                   battery_level_update() is too slow */
-                if (    (battery_level() < charge_restart_level)
-                        || (power_history[POWER_HISTORY_LEN-1] <
-                            BATTERY_LEVEL_DANGEROUS)) {
-                    if (charge_pause) {
-                        DEBUGF("power: batt level < restart level,"
-                               " but charge pause, not enabling\n");
-                        snprintf(power_message, POWER_MESSAGE_LEN,
-                                 "chg pause %d min", charge_pause);
-                    } else {
-                        /* calculate max charge time depending on current
-                           battery level */
-                        /* take 35% more because some more energy is used for
-                           heating up the battery */
-                        i = CHARGE_MAX_TIME_1500 * battery_capacity / 1500;
-                        charge_max_time_now =
-                            i * (100 + 35 - battery_level()) / 100;
-                        if (charge_max_time_now > i) {
-                            charge_max_time_now = i;
-                        }
-                        snprintf(power_message, POWER_MESSAGE_LEN,
-                                 "ChgAt %d%% max %dm", battery_level(),
-                                 charge_max_time_now);
-
-                        /* enable the charger after the max time calc is done,
-                           because battery_level depends on if the charger is
-                           on */
-                        DEBUGF("power: charger inserted and battery"
-                               " not full, enabling\n");
-                        powermgmt_last_cycle_level = battery_level();
-                        powermgmt_last_cycle_startstop_min = 0;
-                        charged_time = 0;
-
-                        charger_enable(true);
-                        charge_state = 1; /* 0: decharging/charger off, 1:
-                                             charge, 2: top-off, 3: trickle */
-                        /* clear the power history so that we don't use values
-                           before discharge for the long-term delta
-                         */
-                        for (i = 0; i < POWER_HISTORY_LEN-1; i++)
-                            power_history[i] =
-                                power_history[POWER_HISTORY_LEN-1];
-                    }
-                }
-
         } else {
-            /* charger not inserted */
-            if (charge_state > 0) {
+            if (charge_state != DISCHARGING) {
                 /* charger not inserted but was enabled */
                 DEBUGF("power: charger disconnected, disabling\n");
-                powermgmt_last_cycle_level = battery_level();
+
+                charger_enable(false);
+                powermgmt_last_cycle_level = battery_percent;
                 powermgmt_last_cycle_startstop_min = 0;
-                /* show in debug menu that trickle is off */
                 trickle_sec = 0;
-                charger_enable(false);
-                charge_state = 0; /* 0: decharging/charger off, 1: charge, 2:
-                                     top-off, 3: trickle */
-                snprintf(power_message, POWER_MESSAGE_LEN, "Charger disc");
+                charge_state = DISCHARGING;
+                snprintf(power_message, POWER_MESSAGE_LEN, "Charger: discharge");
             }
-            /* charger not inserted and disabled, so we're discharging */
         }
         powermgmt_last_cycle_startstop_min++;
         
 #endif /* HAVE_CHARGE_CTRL*/
-#endif /* # if CONFIG_BATTERY == BATT_LIION2200 */
-        
-        /* sleep for roughly a minute */
+
+        /* sleep for a minute */
+
 #ifdef HAVE_CHARGE_CTRL
-        i = 60 - trickle_sec - POWER_AVG_N * POWER_AVG_SLEEP;
+        if(trickle_sec > 0) {
+            charger_enable(true);
+            power_thread_sleep(HZ * trickle_sec);
+        }
+        if(trickle_sec < 60)
+            charger_enable(false);
+        power_thread_sleep(HZ * (60 - trickle_sec));
 #else
-        i = 60 - POWER_AVG_N * POWER_AVG_SLEEP;
+        power_thread_sleep(HZ * 60);
 #endif
-        if (i > 0)
-            power_thread_sleep(HZ*(i));
 
+#if defined(DEBUG_FILE) && defined(HAVE_CHARGE_CTRL)
+        if((fd < 0) && !usb_inserted()) {
+            fd = open(DEBUG_FILE_NAME, O_WRONLY | O_APPEND | O_CREAT);
+            snprintf(debug_message, DEBUG_MESSAGE_LEN,
+            "cycle_min, bat_centivolts, bat_percent, chgr, chg_state, trickle_sec\n");
+            write(fd, debug_message, strlen(debug_message));
+            fsync(fd);
+        } else if((fd >= 0) && !usb_inserted()) {
+            snprintf(debug_message, DEBUG_MESSAGE_LEN, "%d, %d, %d, %d, %d, %d\n",
+                powermgmt_last_cycle_startstop_min, battery_centivolts,
+                battery_percent, charger_inserted(), charge_state, trickle_sec);
+            write(fd, debug_message, strlen(debug_message));
+            fsync(fd);
+        } else if((fd >= 0) && usb_inserted()) {
+            /* NOTE: It is probably already TOO LATE to close the file */
+            close(fd);
+            fd = -1;
+        }
+#endif
         handle_auto_poweroff();
     }
 }
@@ -862,31 +881,9 @@ void powermgmt_init(void)
     /* init history to 0 */
     memset(power_history, 0x00, sizeof(power_history));
 
-#if 0
-    /* initialize the history with a single sample to prevent level
-       flickering during the first minute of execution */
-    power_history[POWER_HISTORY_LEN-1] =
-        (adc_read(ADC_UNREG_POWER) * BATTERY_SCALE_FACTOR) / 10000;
-    /* calculate the first battery level */
-    battery_level_update();
-    /* calculate the remaining time to that the info screen displays something
-       useful */
-    powermgmt_est_runningtime_min =
-        battery_level() * battery_capacity / 100 * 60 / CURRENT_NORMAL;
-#if MEM == 8 /* assuming 192 kbps, the running time is 22% longer with 8MB */
-    powermgmt_est_runningtime_min = powermgmt_est_runningtime_min * 122 / 100;
-#endif
-    
-#ifdef HAVE_CHARGE_CTRL
-    snprintf(power_message, POWER_MESSAGE_LEN, "Powermgmt started");
-    
-    /* if the battery is nearly empty, start charging immediately */
-    if (power_history[POWER_HISTORY_LEN-1] < BATTERY_LEVEL_DANGEROUS)
-        charger_enable(true);
-#endif
-#endif
-
+#ifdef HAVE_CHARGING
     charger_power_is_on = charger_inserted();
+#endif
     
     create_thread(power_thread, power_stack, sizeof(power_stack),
                   power_thread_name);
@@ -898,11 +895,17 @@ void powermgmt_init(void)
 void shutdown_hw(void) 
 {
 #ifndef SIMULATOR
+#if defined(DEBUG_FILE) && defined(HAVE_CHARGE_CTRL)
+    if(fd > 0) {
+        close(fd);
+        fd = 0;
+    }
+#endif
     mpeg_stop();
     ata_flush();
     ata_spindown(1);
     while(ata_disk_is_active())
-    sleep(HZ/10);
+        sleep(HZ/10);
 
     mp3_shutdown();
 #if CONFIG_KEYPAD == ONDIO_PAD