Warning: don't leave your Pandora plugged in for too long

[WizardStan]

Uh oh.


We use a lithium-ion polymer (Li-Po) battery, right?

Oh, and it should be noted that the article is referring to the act of trickle charging an idle battery: that is, the battery is sitting in a charger with nothing but ambient discharge being compensated by the charger; it says nothing about trickle charging a battery that is in use, which is a moderately different situation. I'm fairly certain I remember from my days working with lithium cells on my schools solar car that top up charging while the battery was in use was entirely "safe" (for definitions of safe that do not include leaving it charging for months or even weeks )


That being said, a battery at 100% for an extended period of time is still a bad idea, and an intelligent "I've been plugged in for more than 48 hours so I'm just going to discharge to 40% m'kay" driver may not be a bad idea.

 

[ImmaculateChimp]

for future reference, when I get my Pandora, if I need or just want to charge it over night is that safe?(and than unplug the charger when I wake up) also in the overnight charging scenario which is better, leaving it in "sleep mode" or turning it off?

 

[john4p]

I second this question.

 

[Eridger]

for future reference, when I get my Pandora, if I need or just want to charge it over night is that safe?(and than unplug the charger when I wake up) also in the overnight charging scenario which is better, leaving it in "sleep mode" or turning it off?

Well first off, the Pandora cannot be charging and be off at the same time; the board's design wouldn't allow it. Instead it goes into a primitive (for now) 'low power state', where the processor is underclocked to around 14MHz and the screen turns off. Not sure what else happens, but I know it can definitely be worked on.


And overnight charging is fine (so far. Most likely is going to stay that way, too). These guys left their Pandora alone for INSANE amounts of time. Weeks to Months. No one has had any problems with this sort of thing.


So leaving it charged overnight? A day? Maybe two? Sure, no problem. Leaving it charging for a week or three? Better not. At least not until a fix comes out.


Um... a driver fix can be made for this, right guys? I mean the firmware is open right? Or some sort of management can be written into the kernel?

 

[Hitnrun]

Wow, I've had exactly this problem with my Nokia N95 this week, the battery started losing charge too quickly, so I left it always plugged, either at home, on the car, or at work.


The back of my phone started to "open" by itself, but I tought that the problem was with the back flip, as one of the locks broke. So I glued it with SuperBonder, and kept using it.


Now after reading this thread, I went to take a look at my battery, and it is like the battery on the first post, it is "fat", that is why the back flip was opening and broke! I never knew this could happen!


I will take a picture later and post here so you can see if it is the same problem.

 

[urjaman]

Okay, here's something for the developers to test: http://urjaman.dyndns.info/charged.c (supposed to be "Charge Daemon"). Source only release because I want you to look in the source and atleast tune the tunables to your liking. Debug messages are quite sparse due to developing this on the pandora.


But I think adding config file support, daemonizing and support for kicking it out of "idle" state, it could be usable on a wider scale. License will be GPLv3, havent added any banners yet. And yeah it also supports "stopping" the charge phase to arbitary percentage. Also, it cant stop charging if your pandora is using less than about 100mA (my safety limit over 80mA), because that would entirely stop the charge cycle (as wizardstan has noticed) - and yeah entirely might be until you reboot it.


But it seems capable of keeping my pandora at 63%, so releasing it for further development and testing (I'm hoping that someone else could be the maintainer).


And FFS people, dont be so OMG scared, cheer up, your pandora is not going to explode overnight


EDIT: Dunno why, but it seems that holding the charging process at a deadstill will kick in some sort of a timer that disables it. This works for some time, then I need to turn off the pandora to have it charge again. You have been warned... (Need a kernel fix then...).

 

[Bosbeetle]

And FFS people, dont be so OMG scared, cheer up, your pandora is not going to explode overnight

true, thats something we can say, since these have been on for months without exploding.

 

[Tor]

Yeah. I took a picture after I put it in a trash bag. The battery is going in the garbage tomorrow. [..]

You're not literally throwing it in the garbage I hope.. these batteries should be recycled and in any case never dumped in a landfill.

 

[darfgarf]

these batteries should be recycled

at the least, if you walk to somewhere that recycles them (in the uk it's anywhere that sells them), and hand them that, they'd run a mile XD

 

[WizardStan]

Okay, here's something for the developers to test: http://urjaman.dyndns.info/charged.c (supposed to be "Charge Daemon"). Source only release because I want you to look in the source and atleast tune the tunables to your liking. Debug messages are quite sparse due to developing this on the pandora.

I've been toying with that idea myself, except encoding it right into the kernel so it can take advantage of interrupts, built in timers, etc... Your idle loop wakes up, checks the level, and then goes back to sleep, but the chip can actually be configured to trigger interrupts at different voltage levels: no need to wake up and check, just sit waiting for the interrupt. A 4 hour timer can also be configured: reset the timer every time it goes off and keep a count, and there's your 12, 24, or 48 hour. There's also an interrupt for when AC and USB are plugged and unplugged so you wouldn't have to rely on the original max amps to decide which one is connected.

 

[Link]

Wow, I've had exactly this problem with my Nokia N95 this week, the battery started losing charge too quickly, so I left it always plugged, either at home, on the car, or at work.


The back of my phone started to "open" by itself, but I tought that the problem was with the back flip, as one of the locks broke. So I glued it with SuperBonder, and kept using it.


Now after reading this thread, I went to take a look at my battery, and it is like the battery on the first post, it is "fat", that is why the back flip was opening and broke! I never knew this could happen!


I will take a picture later and post here so you can see if it is the same problem.

Pretty sure my Droid X states that the unit should not be kept on the charger for extended periods.

 

[may88]

You mean like this ?

Oh ah! Timely post - wrong forum though.

You're not literally throwing it in the garbage I hope.. these batteries should be recycled and in any case never dumped in a landfill.

Exactly - Come on guys think green! Without hugging too many trees, we need to stop sticking poisonous crap like this in the ground.

 

[TitanUranus]

Maybe you could use it as a selling point. Some devices offer feedback vibration, but could pandora be the first to actually offer real explosions during your gaming experience?


"Lose your gonads as your Pandora goes nuclear in continuous mains powered OCD style gaming sessions!"


EDIT: Disclaimer in the manual should definitely read "Never leave your Pandora plugged into the mains for '2 months™ "


Also I have no friends, please - someone be my friend

 

[myownlittlworld]

Maybe you could use it as a selling point. Some devices offer feedback vibration, but could pandora be the first to actually offer real explosions during your gaming experience?


"Lose your gonads as your Pandora goes nuclear in continuous mains powered OCD style gaming sessions!" ...


Also I have no friends, please - someone be my friend

That was awesome enough to earn you a friend.


Too bad the explosion effect could only happen once though. But wow, what a way to end a game of Doom or something!

 

[QazzaQY2K]

I'm having this similar problem. I use my Pandora pretty much everyday. Then I load it over night. Some times on weekends I forget it and do other stuff. It stays with loading the entire day. Then Once going to bed. To watch something on the Pandora, Its most of the time turned off. (Not by anyone) Feels very warm and wont turn on. First after lots of cooling down. Turnings the Pandora on again. I'm still getting lucky that it turns on. What am i Supposed to do if I forget about taking out the AC? Also .. if I got it in Power Save mode.. it wont last longer then 10 hours anyway Still would need loading. Not sure if even in off mode the battery is eating the power away at an alarming rate.


How are we supposed to use the charing with out the hassle to remember to take it out every day. Then putting it back on the Charging? Or this is just the pandoraian way to live now?.

 

[EvilDragon]

I'm having this similar problem. I use my Pandora pretty much everyday. Then I load it over night. Some times on weekends I forget it and do other stuff. It stays with loading the entire day. Then Once going to bed. To watch something on the Pandora, Its most of the time turned off. (Not by anyone) Feels very warm and wont turn on. First after lots of cooling down. Turnings the Pandora on again.

Hmm, that is weird. I often have it connected for a few days, that's no issue and shouldn't do anything.


People here were talking about MONTHS, not days.

I'm still getting lucky that it turns on. What am i Supposed to do if I forget about taking out the AC? Also .. if I got it in Power Save mode.. it wont last longer then 10 hours anyway Still would need loading. Not sure if even in off mode the battery is eating the power away at an alarming rate.

Is the battery losing power when the unit is switched off?


Sounds like a broken USB chip then - as that shouldn't happen.


That could also explain why it gets too warm when charging.

 

[QazzaQY2K]

I'll see if I can make a test or two to make sure its as bad as I say. Have it fully charged. Unplug it from PowerSuply, see how long its going to last in power save mode.


Also have the issue that when waking it back up. The nubs aren't working. Have too reboot so they get working again.

 

[WizardStan]

if I got it in Power Save mode.. it wont last longer then 10 hours anyway Still would need loading. Not sure if even in off mode the battery is eating the power away at an alarming rate.

If you can, charge it to 100% and then shut it completely down (not just power save) for 24 hours. It should lose only 1 or 2%, but if you have a problem with the battery it may be much more, possibly even be completely dead. It seems to be a rare thing, reading the boards.

 

[Grench]

Frankly the statements I'm seeing from ED and MW on this one shock the heck out of me. I find them to be downright scary in fact. A swollen and deformed battery is a sign of something very very wrong - and potentially dangerous as hell.

Hmm, that is weird. I often have it connected for a few days, that's no issue and shouldn't do anything.


People here were talking about MONTHS, not days.

It really sounds like blaming the end consumer for what sounds like potentially dangerous design flaw.


It should not matter. Handheld radios, cell phones, laptop computers, smart phones - they all get left plugged in 24/7 in store displays. I haven't heard of one burning down a store yet. There are no public service announcements going off telling everyone to unplug all battery operated devices each night before we go to bed or risk fire and certain death.


Standard consumer behavior is to leave the device on the charger all the time that the device is not mobile. Meaning that a PMP type device may get left plugged in for days or weeks in between trips/flights. The device should not care as the protection should be covered in the battery. - I'll get to that in a sec...


If your device is -able- to supply additional full-charging power to an already fully charged battery (regardless of type - and regardless of it's remaining charge capacity), then it is dangerous. The fact that it was designed to do so???? Huh? I don't think blaming TI cuts it. Who designed the battery?

Is the battery losing power when the unit is switched off?


Sounds like a broken USB chip then - as that shouldn't happen.


That could also explain why it gets too warm when charging.

Most modern Li-Ion cells are built with an overcharge protection circuit built into them. Was the Pandora battery built without an overcharge protection circuit?


See: http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries


"Commercial lithium ion packs contain a protection circuits that limit the charge voltage to 4.30V/cell, 0.10 volts higher than the voltage threshold of the charger. Temperature sensing disconnects the charge if the cell temperature approaches 90°C (194°F), and a mechanical pressure switch on many cells permanently interrupt the current path if a safe pressure threshold is exceeded. Exceptions are made on some spinel (manganese) packs containing one or two small cells."


Was the battery in the Pandora built without these safeguards?


Do we have a raw pack of Li-Ion cells wrapped in plastic or is there proper over charging protection circuitry and fail safes built into the battery packaging?

 

[WolfSpider]

There has been some exploding iPod Touches before, if any of it was true.