Battery voltage/overcharging issue

[Mooncatt]

I noticed the battery on my Droid Bionic has swollen, and I know I need to replace it. I was looking into things and noticed that while my factory battery is listed on the back to be rated for 3.8V, my battery monitor app is reporting 4.338V. I know that's not good and subsequently have to run it down to 80% to get to 3.8V, but also sometimes seeing the voltage rise a bit here and there despite not on the charger.

So my question is what causes the battery voltage to get up so high? Is it indicating a bad charger (even though USB its rated about 5V already), something wrong in the phone, or just a side effect of the battery going bad for other reasons (i.e. Getting too hot)? The only info I've found so far just says standard Li-on cells are not good above about 4.2V, but nothing on potential causes in phone use. Thinking of getting an extended battery, but don't want to spend the extra money if I have to worry about it getting a high voltage charge too.

 

[Scott Kenyon]

Are you using the charger that came with the phone?

 

[Mooncatt]

I drive for a living, so it's usually on an aftermarket car charger, but at home and when shut down it's on the OEM stock charger. The battery goes above 4V on both.

 

[Golfdriver97]

I drive for a living, so it's usually on an aftermarket car charger, but at home and when shut down it's on the OEM stock charger. The battery goes above 4V on both.

I have heard aftermarket car chargers can overcharge batteries quite easily. One way to test it is if the car charger charges the phone to full in a significantly shorter time than the stock, then it is getting charged too quickly.

 

[Mooncatt]

I've done some charger researching a while back when looking for a new one, and from what I've found, I don't think the charger would be the issue. If it was pushing too high a voltage (which it shouldn't with the USB standard unless defective), I would expect other issues to pop up with the function of the phone itself. The amperage rating would have nothing to do with it, as it's the phone that determines how many amps to actually draw. It's the same thing as how a stock wall charger and big microwave can both use the same 30 amp home circuit. I don't buy much into the "fast charge" hype of stronger chargers, but I like them because the charger itself doesn't have to work as hard and can theoretically last longer and be more universal.

I guess something could have happened to the phone making it send too much juice to the battery, but haven't found anything really explaining how feasible that could be and part of why I'm asking about this stuff. I'm *thinking* it's a battery only issue because the Bionic does get toasty under a heavy load. I know that isn't good for batteries. There's been a few times USB power stopped and the battery started discharging due to the heat when gaming, plugged in, and warm ambient temps. I think I've seen it spike to 120? a couple times before I realized it and got it cooled down. The phone itself never got hot enough to go into protection mode, though.

 

[garublador]

4.2V is normal for Li-Ion batteries, so it getting above 4V isn't an issue. You'll likely see it get to 4.2V at 100% charge. That's normally considered the safe max. However, 4.338V, if that is accurate, is too high and would likely shorten the battery life and you'd get the "bulging" that you're seeing. It sounds suspiciously close to what the protection circuitry in a battery would cut off at to avoid getting charged so high that it gets destroyed. I'm skeptical that the battery itself could cause that. It's more likely that the charging circuit was somehow damaged and is outputting too high a voltage. I don't know for sure how the phone gets those voltage readings. It could also be that your battery is just worn out and that's somehow making the voltage reading not very reliable. I don't know if that's possible or not.

How old is the phone and when did you start noticing that the battery needed to be replaced? If you don't have too much longer on your contract before you can get a new phone you can just buy a new battery and hope that it lasts you long enough. If you can find a place with a return policy that allows it you can get a new battery and see what voltage your phone reports when it's fully charged. If it's still high and you don't want to worry about running a new battery into the ground you can just return it.

 

[Mooncatt]

The phone is a little over a year old and I first noticed the bulge maybe a week ago, but shortened life for maybe two weeks now. At first I figured it was normal capacity loss, but then I noticed the bulge just by chance because you have to remove the battery cover to access the micro SD card. I have another battery on order now, so hopefully this one lasts until then.

 

[Golfdriver97]

The phone is a little over a year old and I first noticed the bulge maybe a week ago, but shortened life for maybe two weeks now. At first I figured it was normal capacity loss, but then I noticed the bulge just by chance because you have to remove the battery cover to access the micro SD card. I have another battery on order now, so hopefully this one lasts until then.

I had a bulge on my S2, and it caused similar issues. New one fixed it.

Sent from a M.O.A.R. Galaxy S3

 

[problemshredder]

yes 4.338v is higher than max safe voltage. lithium polymer batteries are supposed to reach up to 4.2v then remain constant voltage till finishes charging. it maybe caused by the aftermarket charger, which is, more likely to not safeguard specific model. stock charger will not cause the bulge, this is also why manufacturers always suggest using the stock provided charger. so, i think it's safe to buy an extra battery if you stick to using approved stock chargers.

 

[Mooncatt]

I know manufacturers recommend only OEM chargers, but recommendations like that are often not necessary and are made from a liability and/or profitability standpoint. I've already addressed my opinions of the use of aftermarket chargers, but I'm interested if you have more specific information that may link it as the problem.

Now if I were using an aftermarket external charger where I pull the battery out and set into a charging cradle, I could certainly understand it being a potential issue. Though with USB charging through the phone, it's my understanding the phone regulates the charge and the "charger" is actually nothing more than a simple constant power source.

 

[garublador]

I agree with Mooncatt's analysis. I'm too lazy to try to figure out exactly what charging circuit they're using in the S4 (if that information is even available), but I'd guess that it will work just fine with any, even semi-reputable charger. You'd have to be way, way out of spec to damage most charging circuits and most catastrophic events that could damage the charging circuit would likely take out the charger itself as well. I can't imagine a company like Samsung risking a "charge-gate" type problem by using a really crappy charging circuit. It's one of those things in a cell phone that has to be super robust.

 

[Mooncatt]

Got my new battery, the OEM extended one since I have wanted one anyway. It looks like the charging circuitry is built into the battery, not the phone sensing the condition and charging as needed. Soon as I plugged in and charged it fully, it pegged 4.2V and stayed. Though, after finding out that Li-ion batteries can loose capacity quicker by being held at max voltage, I think I'm going to stop leaving it plugged in nearly all the time and go to recharging as needed.