Battery voltage to high?

[anon(10181084)]

So yeah, my phone (CAT S41) battery has been charging to 4.3+ volts. Noticed this last year. Not sure if this is a sign for any concern. What is worrying me is that on AccuBattery (I installed this on Monday and hope for an accurate battery capacity measurement in a few days, so far not looking too promising...) and the battery voltage is in the red zone. I've read thru an old thread here on AC regarding charging on the S3/S4, but that is a bit outdated. I will also provide a screenshot of early capacity measurements, but my SoT hasn't suffered too much (maybe my phone addiction is getting better?).

 

[chanchan05]

Accubattery isn't really all that accurate. It's just estimates. Don't worry about it.

 

[Mooncatt]

In this case, I would. The capacity estimate may be questionable, as I've seen other users reporting it to be fairly accurate over time, but that voltage is a little concerning.

To the OP, many Li-ion batteries are now designed to charge to 4.3V, but going over that can certainly damage them. Even if it's a small amount. It could be a sign that the battery itself is going bad, or the voltage regulator in the phone is over-charging. If you can replace the battery yourself (I'm not sure if it's a sealed phone), I'd try that. Or at the very least, take the current battery out and look for signs of puffing up. You can also put it on a flat surface and try to spin it. If it doesn't spin, it's possibly ok, which means something else is wrong. If it keeps spinning, it's already puffing up even if it's not visible to the naked eye yet. Over charging a battery like this can essentially boil the chemicals in it, which creates gases that cause it to puff up.

A puffed up Li-ion battery can be dangerous if not carefully handled. So if this is the case for yours, you ideally shouldn't use it any more and replace it asap. Then store the battery in a container to prevent being punctured (preferably one that's fire resistant/proof in case it decides to ignite) and take it to some place that can handle recycling a damaged battery. DO NOT just drop it off in one of those self serve recycling bins some stores have, or just toss it in the trash. That's just asking for it to be punctured and go up in flames. Make sure you let the shop you take it to know that it's damaged so they can properly take care of it.

If you do try putting a new battery in yourself, check it carefully during the first few charge cycles to make sure it doesn't go over the voltage rating listed on the battery itself (4.2V or 4.3V) to make sure it's not the phone itself causing the problem. And on a related note, I noticed you're charging close to 100%, which can shorten the life of batteries over time. It's best to keep them between 40-80% if longevity is a concern.

 

[anon(10181084)]

My phone is, thank God, not spinning. The phone works great, but I'm not sure whether it is me or what but the phone does seem to be charging a tad bit faster than usual. SoT is still good, so I am not worried (yet) about any issues regarding that. This voltage thing is weird and a bit scary. My father (who has a PhD in electrical engineering) just blew off my worries a few months ago claiming the phone is smart enough to have a safety cutoff. I cannot physically check the battery, since my phone is sealed. My phone is only a year old. Here are screenshots of the AccuBattery status after the last charge cycle finished completely. Under those, there is a teardown pic showing the battery ratings. If it matters, my phone uses Mediatek Pump Express. As for the capacity estimate, I will have to charge my phone a few more times to believe the readings.

 

[Mooncatt]

My phone is, thank God, not spinning.

No, it's the battery itself that you'd do the spin test, not the phone. The battery could be puffed inside the phone without deforming the phone body.

I do have good news, though. I did a little digging on the battery. From everything I'm finding that shows the battery pack itself, it luckily shows the full charge voltage (most only show the resting charge), which is rated at 4.4V. That's odd for a Li-ion battery so I can't speak to how that translates to performance and longevity. But, it means that it isn't being over charged based on the specs. My guess is that Accubattery isn't programmed to know such a battery exists. On a regular Li-ion battery with a max voltage of 4.2-4.3V, it's understandable that you'd see the red line for over voltage.

 

[anon(10181084)]

No, it's the battery itself that you'd do the spin test, not the phone. The battery could be puffed inside the phone without deforming the phone body.

I do have good news, though. I did a little digging on the battery. From everything I'm finding that shows the battery pack itself, it luckily shows the full charge voltage (most only show the resting charge), which is rated at 4.4V. That's odd for a Li-ion battery so I can't speak to how that translates to performance and longevity. But, it means that it isn't being over charged based on the specs. My guess is that Accubattery isn't programmed to know such a battery exists. On a regular Li-ion battery with a max voltage of 4.2-4.3V, it's understandable that you'd see the red line for over voltage.

Thanks! Now I don't have to worry about the voltage. Phew... That red line gave me a nasty scare. I guess I'm a bit paranoid after the whole Note 7 fiasco 2.5 years ago... Anyways, thanks for the info handling a bloated batteries since I do have some old devices with sealed batteries laying around in my "old tech" cabinet that have pretty worn down batteries.