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Thread: HELP: 3GS battery replacement??!
09-25-2010, 03:31 PM #1
HELP: 3GS battery replacement??!
I have a 3GS... the battery has started to die premature, as in once it hits between 30%-50% the phone powers down... or sometimes earlier... as it seems that also when the phone is under heavy load it will die as well.
I purchased a new battery OEM, and installed it(the part# of battery is the same). Now the battery will not charge at all. It still syncs, but it wont charge.
The little battery icon just shows a plug, as opposed to the little lightning bolt.
Thinking the new battery was defective I ordered another(replacement), and did the install again. Same thing.
For the meantime I reinstalled the old battery, and it is once again able to charge... although the problem persists on the phone powering off much earlier than it should..
Anyone have any ideas what the problem might be? Am I doing something wrong? Is it possibly not the battery that is defective? Could it be something else?
10-05-2010, 04:29 AM #2
When it powers down is the phone so dead that it won't power on without plugging it in?jailbroken ?
10-05-2010, 05:13 PM #3
* the battery charging circuit may be dying. It would explain similar behavior with old/new battery, and might account for the initial trouble you had with your old battery. It wouldn't really show different behavior with new and old batteries though.
* the replacement battery is MISSING some necessary circuitry that mates with the charger. There could be some OEM stuff Apple adds before they install it. I'm not sure how "smart" the bare batteries are themselves. Are there any visible differences between the old and new ones, at all?
* the vendor sent you two bad apples (barrelful of bad apples?) They could be a refurb, and a poorly built one at that. SOME battery vendors are notorious for this; you could Google and see if anyone's reported shady business from this reseller.
* you goofed when putting it back together, somehow. If you successfully reinstalled the original, I imagine you have a pretty good idea how to disassemble/reassemble by now, and this isn't the problem.
My guess on what's wrong with the original:
some combination of-
* dead/dying charge circuit. Charges your battery up to a 'full' voltage that's much lower than it should. It could happen if you frequently charge your iPhone from questionable or unstable power sources (3rd party chargers, rather than Apple cable, and a desktop PC/Mac). Difficult or impossible to replace, unfortunately . Hopefully its *not* this.
* battery with degraded capacity. Charges up to a 'full' voltage that's pretty close to reference, but can't keep it up for too long. The "percentage full" numbers are only an estimate, and usually assume the battery is healthy. When it reads "50%", its really < 10% and at "30%" close to zero. When you're under heavy load, the voltage may spike downward below the minimum reference value, and the iPhone (or the battery itself) shut down. (let it rest a few minutes, and you may still have enough residual power to run for awhile). This is the most likely, and if you're unlucky you might have both a dead battery AND a dead charge circuit.
What I'd suggest:
if you have a voltmeter handy, check the voltage on your "old" battery, just after charging it to "full" capacity. Check the voltage on the replacement and see if its anywhere near.
You could check the replacement as-is (without tearing apart the iPhone again) though it may read lower than expected since you're not under load.