updated because of trickle charge
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2984 a1c6a512-1295-4272-9138-f99709370657
diff --git a/docs/BATTERY-FAQ b/docs/BATTERY-FAQ
index 07a7e37..31aa82a 100644
--- a/docs/BATTERY-FAQ
+++ b/docs/BATTERY-FAQ
@@ -11,14 +11,21 @@
Q2: Will keeping my charger connected a long time damage my batteries? Can I
leave it over night?
-A2: The charger logic lets the batteries charge until they are full. After
- that, the charger is disabled, but the device will stay powered on and
- continue to consume some power from the batteries (the hardware does
- not allow running from the charger without charging batteries, or
- powering off with the charger connected). After some time, it will
- start charging the batteries again to keep them full. This will
- wear the batteries a little, but overnight charging is what most
- people do.
+A2: There's a deep discharge mode and you can switch trickle charge on and off.
+ If you use your AJB connected to the power supply the whole time, select
+ "deep discharge on" and "trickle charge off". 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).
+
+ Trickle charge is needed to keep the batteries full. That's necessary because
+ the device will stay powered on and continue to consume some power from
+ the batteries (the hardware does not allow running from the charger
+ without charging batteries, or powering off with the charger connected).
+ The trickle charge time is 12 hours. It should be enough for you to disconnect
+ your AJB in this time and turn it off / use it.
+ However, after 12 hours of trickle charge, it will turn it off, the batteries
+ are discharged and another charge cycle is started.
As the Battery FAQ at http://www.greenbatteries.com/ puts it:
"A NiMH battery can be charged and discharged hundreds of times,
@@ -30,18 +37,22 @@
A3: Player: Rockbox doesn't affect the charging on Players, it is all done
by hardware logic out of software control.
- Recorder: The current release of 1.2 is much worse than the Archos
- charger, it tends to stop charging much too early and leave the batteries
- half empty.
+ Recorder: The whole algorithm is made to carefully charge the batteries full
+ and keep them full after that with a trickle charge option. Many documents
+ about charge ICs were considered. If you want to know details, then look
+ into docs/CHARGING_ALGORITHM. If you have comments, write to
+ mail@uwe-freese.de or the Rockbox mailinglist.
+
+ Test results with trickle charge (battery capacities measured with an
+ external charger, Model "Conrad Electronic Charge Manager 2010", ~100 EUR):
+
+ - after normal charge and top off time: 1798, 1834, 1819, 1815 mAh
+ - after normal + top off + trickle charge (12h): 1784, 1748, 1738, 1752 mAh
+ - charged with external charger: 1786, 1819, 1802, 1802 mAh
- The current development code (CVS daily builds as of 20.8.2002) is much
- better than the 1.2 release, but still not perfect. Linus recently
- measured 6 hours continuous playtime after a rockbox charge, and much
- over 7 hours after an Archos charge. We are working on fine-tuning
- the charger logic to get the most out of the batteries, but the
- emphasis is on not overcharging them, since that would damage the
- batteries. Better be safe than sorry.
-
+ You can see, whenever you take your AJB with you in the 12h trickle charge
+ period, the batteries are at least 97% full. :)
+
Q4: What kind of batteries are there in my factory default Player/Recorder?
A4: Both ship with 1500 mAh NiMH (Nickel Metal Hydride) batteries.
@@ -63,13 +74,15 @@
online shops. Browse around. There's a pretty good comparison between
different battery makes and models at the digital imaging resource site:
http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM
+ In Germany, www.reichelt.de sells GP 2000 batteries for 2,75 EUR (12/2002).
Q7: What kind of run-time can I expect on a set of fully-charged batteries
when running Rockbox?
A7: For the stock 1500 mAh cells, from 6 hours to 8 hours, depending on
- which charger was used (see Q3). It depends a lot on the condition of
- the batteries. We are looking into implementing more battery-saving
- techniques in rockbox to make it rock longer.
+ which charger was used (see Q3). It depends a lot on the condition of the
+ batteries. With 2000 mAh batteries, you should reach about 10 hours or more.
+ We are looking into implementing more battery-saving techniques in rockbox
+ to make it rock longer.
Q8: Can I use different batteries in my Archos? How much playtime would
I gain by using 1800 mAh batteries instead of the 1500 mAh ones?
@@ -205,4 +218,3 @@
However, if you use your AJB connected to the charger all the time,
we recommend you to use the deep discharge option.
-