Battery has gone inert

[Chairman_Now]

I bought two batteries. Both have functioned fully in the past.


One is now just completely dead. It seemingly will not charge, but I only tried for a few minutes. Is there a way to bring it back from the dead? Is the battery covered by warranty?

 

[WizardStan]

If the battery is totally dead, it can take upwards of 30 minutes (or so, maybe longer, who knows) of pre-charging before it's charged enough to even be able to power the Pandora on. During this time, there will be no indication that it's actually doing anything, not even the LED will come on. Once it's charged enough, it'll automatically kick on.


Give that a try and see how it goes.

 

[Eridger]

If the battery is totally dead, it can take upwards of 30 minutes (or so, maybe longer, who knows) of pre-charging before it's charged enough to even be able to power the Pandora on. During this time, there will be no indication that it's actually doing anything, not even the LED will come on. Once it's charged enough, it'll automatically kick on.


Give that a try and see how it goes.

Should work, if the problem with the battery is that it's acutally fully dead. It's a pretty terrible idea to completely drain LiPos though, from what I know.

 

[007jaws]

Should work, if the problem with the battery is that it's acutally fully dead. It's a pretty terrible idea to completely drain LiPos though, from what I know.

Best to buy a new battery, theres one on ebay uk right now for sale?

 

[Eridger]

Best to buy a new battery, theres one on ebay uk right now for sale?

'Best'? Why 'best'? Surely it's not. If you need a spare, you can get a replacement direct. And you might as well tinker with the dead battery to see what's up. I don't mean anything like opening it or whatever, or course. But leaving it in the charger for a day wouldn't be a terrible idea...

 

[Chairman_Now]

If the battery is totally dead, it can take upwards of 30 minutes (or so, maybe longer, who knows) of pre-charging before it's charged enough to even be able to power the Pandora on. During this time, there will be no indication that it's actually doing anything, not even the LED will come on. Once it's charged enough, it'll automatically kick on.


Give that a try and see how it goes.

Strange. I swapped batteries (I had a spare), plugged in the charger, and the Pandora fired right up. Charging light came on immediately.


I guess it was just tired.


I may have left my unit in "sleep" without realizing... Don't other types of electronics handle this situation a bit more gracefully (i.e., do not allow battery to fully discharge)?

 

[levi]

Strange. I swapped batteries (I had a spare), plugged in the charger, and the Pandora fired right up. Charging light came on immediately.


I guess it was just tired.


I may have left my unit in "sleep" without realizing... Don't other types of electronics handle this situation a bit more gracefully (i.e., do not allow battery to fully discharge)?

I've had both my sports watch and a bluetooth GPS unit both appear to be dead and refuse to charge their batteries one day after a period of unuse, then magically come back to life a few days later - the latter waiting until I'd bought a replacement battery Maybe for other devices it's just like the Pandora - the charging lights don't even come on if the battery is beyond a certain state.


I now make it a habit of taking the batteries out of things when I'm not using them. Doesn't stop them draining naturally, but any device without a physical power switch will at least be sucking some juice all of the time. I generally charge all my batteries ever couple of months. In the case of LiPo batteries, I try to leave them at 40%, although most of my devices don't give me an accurate percentage readout.

 

[WizardStan]

I may have left my unit in "sleep" without realizing... Don't other types of electronics handle this situation a bit more gracefully (i.e., do not allow battery to fully discharge)?

When fully off, the battery will still drain away about 1 or 2% per day, since it is being used to maintain state within the Pandora (such as the clock). If you remove the battery it will STILL drain out 1% every two or three days. The Pandora forces a shutdown at about 5% (unless you override it), but even so, left for a few days it will run itself out entirely naturally. This is true of any mobile device: since getting my Pandora, it was almost 3 months until next I touched my PSP, and it's battery was flat from an almost full charge.


The only difference is the Pandora needs the precharge to bring the battery up to a safe level while other electronics allow a constant voltage to start the device at the same time the battery is charged. I'm not certain how they do it, but the charging circuit selected for the Pandora doesn't allow that. It has a lot of other very nice features to compensate, at least.


I occasionally have a problem where I'll forget to charge my Pandora for a few days and find that it has shut itself off from sleep mode. I attempt to turn it back on, but as soon as the desktop loads up it detects that my battery level is less than 5% and immediately initiates shutdown. I have to plug it in before I can do anything with it. Given a day or two at that level, it surely wouldn't even be able to startup at all. Fortunately, I use my Pandora daily, so that hasn't happened to me yet.

 

[Eridger]

...the charging circuit selected for the Pandora doesn't allow that. It has a lot of other very nice features to compensate, at least.

Such as? I love the Pandora, but the charging circuit that was picked seems to be really shoddy. What unique features does this circuit have?

 

[urjaman]

^ There's 70 pages of description in the TPS65950 TRM and about 20 pages in the Data Manual (which is partly overlapping with the TRM in this case).


I think its the same (or very similar) companion device as in the N900. So I'd say that its features are up-to-date but not miraclous.

 

[WizardStan]

Such as? I love the Pandora, but the charging circuit that was picked seems to be really shoddy. What unique features does this circuit have?

Built in temperature control, timers, and voltage level interrupts. Other charge circuits I've seen need a CPU thread to poll these things, while the one in the Pandora will interrupt only when the event actually happens.

 

[lulzfish]

Other charge circuits I've seen need a CPU thread to poll these things

That's horrible design. Do they poll the keyboard and buttons as well?

 

[sverm]

When fully off, the battery will still drain away about 1 or 2% per day, since it is being used to maintain state within the Pandora (such as the clock). If you remove the battery it will STILL drain out 1% every two or three days.

Since excessive discharge can cause Li-Po damage, and it drains even if the battery is removed, what's the best was to store it, let's say for an extended period of time?

 

[WizardStan]

Since excessive discharge can cause Li-Po damage, and it drains even if the battery is removed, what's the best was to store it, let's say for an extended period of time?

Discharge to about 40%, seal it in an airtight container (like a ziplock bag), and store it in your fridge. Probably wouldn't hurt to deflate the bag as much as possible.


It's also suggested to bring it out every few months (6 months to a year maybe?) to just top it back up to 40%

 

[Tor]

Since excessive discharge can cause Li-Po damage, and it drains even if the battery is removed, what's the best was to store it, let's say for an extended period of time?

li-ion/poly drains very little when removed from the device, or when used in a device with true power-off. I have an old gps that I rarely use, I check its charge now and then and it seems to last forever. I charge it every 9 months or so, if I remember, just for the heck of it. I keep it in a cool place, although not in a fridge.

 

[sverm]

My worst fear is forgetting about the Pandora, in say, 5 years from now (it's been over 2 years since I've touched my GBA, 10 years for my C64), then discovering that the battery has dangerously bubbled (or less frighteningly won't hold a charge) and that there are no more supplies left to purchase a new one.