Bad Charging Circuit or Bad Batteries?


rError

Member
Joined
Dec 30, 2012
Messages
86
Location
Canada
I have had my 1Ghz Pandora for about a year now (maybe a bit less) and never had any major problems. I went to a family member's house in January and forgot my Pandora there. It sat for about three weeks. It had ~60% charge, but was left on standby (not full shutdown). I picked it up to find it completely dead, which is understandable. Brought it home and put it on charge, it came back to life within five minutes and proceeded to charge overnight. When I woke up, the charging light was flashing. Opened the Pandora and it said the battery is low and needs to be charged immediately. Odd, but whatever, maybe it didn't charge properly. Unplugged the power adapter, waited a couple seconds, then plugged it back in. The unit started charging, which I confirmed with System Info. This time, I left the unit on like normal (not standby). It seamed to charge normally for a few hours. When I came back, it had stopped, and System Info reported the battery to be above 100% full (~91% of design). Ok cool, maybe just a simple bug. I played with the unit for literally an hour or less, and it reported to be at 60% charge. At this time, I started to wonder if I had killed the battery by leaving it completely dead for so long. A week or so goes by, I recharge multiple times, but this seams to be the case. The battery lasts for a maximum of 4 hours of usage, and less than 2 days on standby. Ok, time for a new battery. I ordered one directly from ED's shop. The new battery arrived, I put it into the Pandora, and System Info reported it at 50%. I put the unit on charge and left it overnight. In the morning it was above 100%, I played it for nearly three hours straight, overclocked for N64 emulation and it reported to be about 80% afterwards. Cool, I thought, problem solved. A few days later when the batter got below 20%, I put it on standby charge. After charging, it reported above 100%. Still normal. I left it alone for two or three days, on standby. When I came back it showed less than 10%. WTF?!? I put it on standby charge, and it sat with the charging light on for HOURS, at least six or more. After getting worried, I turned it back on. LESS THAN 10% REMAINING, ARRRRRGGGGGG!!!! I pulled the battery out, it wasn't warm, put it back in, now it's less than 8%. I put it on standby charge once more. It seamed to charge normally again, when finished, it showed just under 100%. I put it back on standby, came back about two hours later, and it jumped below 70%. F#@&!!!! This is where I am now.

Something is wrong with either the batteries, charger, or the charging circuit. A bit annoyed, but more worried about the condition of Pandy  :(

Any info is appreciated.

P.S. Sorry for the my writing, not using paragraphs and poor wording. Wrote this in a bit of a rush.
 
It could be the battery gauge calibration. They often have trouble reporting correct charges. In fact, the only thing you can really trust from all the battery-related numbers System Info reports, is the voltage, which roughly corresponds to charge (3V is completely empty, above 4.2V is completely full).
 
@rError

Have you left your Pandora without any Powersource (no charger, no battery) for a while ? I think I remember someone giving the advice to leave the Pandora without battery and charger connected for a while in a similar case- I could be wrong though, but maybe its worth a try ?
 
It could be the battery gauge calibration. They often have trouble reporting correct charges. In fact, the only thing you can really trust from all the battery-related numbers System Info reports, is the voltage, which roughly corresponds to charge (3V is completely empty, above 4.2V is completely full).
Is there a way to re-calibrate it?

@rError

Have you left your Pandora without any Powersource (no charger, no battery) for a while ? I think I remember someone giving the advice to leave the Pandora without battery and charger connected for a while in a similar case- I could be wrong though, but maybe its worth a try ?
No, I will try this now. I'll leave it without a battery/power source for at least 24 hours.
 
The battery calibration should sort itself out over time, though the best way I know of to give it good data is to let the battery run out until you get the warning about battery running out (or if you're not watching, up to a few hours after it actually gives out should be fine too), then plug it in and charge it until it won't take any more. Perhaps repeat that two or three times at most, but at some point it should start to realise what it's min and max voltages look like and sort itself out.
 
Is there a way to re-calibrate it?
You can force a recalibration by fully charging it (monitor the voltage until it exceeds 4.2 and the charging amperage drops below (or at least near) 80ma), then unplugging it and shutting down for 5 hours; turn it back on and use it, drain the battery down until it reaches 3.0 volts and then shut it off for another 5 hours. If it stops charging before reaching 4.2 volts just keep unplugging it and plugging it back in until it continues charging. If it reaches 0% but still isn't 3.0 volts cancel any warnings and shut down prompts.You may need to do this twice.
 
Back
Top