kingerp

So, supposedly you can tell if your phone's battery is bad by putting it on a flat surface and trying to "spin" it (as if you were playing spin the bottle). If it spins, supposedly the battery is swollen and needs to be replaced.

Is this for real? And if so....why? I haven't seen one result on Google that says "this is why this test is useful."

I ask because my phone's battery seems to be draining a lot faster than usual (despite the fact that I have the brightness down, auto-sync off, etc) and I don't want to buy a new one if I don't have to.

Thanks in advance!

Dngrsone

Well... if the battery is swollen; then yes, the rounding of the case will allow it to spin freely.

If the case of the battery is flat, then it is unlikely to spin much, no?

Usually, the bulging is obvious and visible to the naked eye.

A swollen battery means there is damage to it internally, and it will not charge correctly nor store very much charge.

kingerp

That's what I thought too (re: bulging), but I keep finding videos like this one where both batteries appear flat to the naked eye, but people are claiming that the one that spins is somehow defective.

Dngrsone

Yeeeeah... first, those are two different batteries (as in type/model/size/shape); second, we don't see the bottom of the 'spinny' battery, so there could be something small attached to the other side of the battery to allow it to spin slightly better than the other, larger one.

Third, if this is their idea of a precision test of some sort, I think I would go with some other vendor, perhaps one with a set of calipers or something similar.

kingerp

I realize that, but from reading XDA I get the feeling that this is a somewhat common way thing that people do to test their batteries. And I want to know if there's any actual basis in reality for the "if it spins, it's bad" assumption.

Dngrsone

In a word: yes.

Batteries which are swollen have internal damage and will not work the way they are intended to.

Frisco

Bulging Lithium-Ion batteries often get that way from excess heat (leaving phone on dashboard, etc) or from the user being in the habit of having them remain on the charger nearly 100% of the time.

The bigger laptop batteries seem to tolerate the long charge times better than the mini batteries we're using in our phones. There is circuitry in all these modern batteries now, not just a charging medium. Usually a little chip that helps calibrate and regulate charging input. The medium itself might become dry and corrupted over time, for reasons mentioned above, etc, and time for a battery change.

I had one "pop" in my Samsung Instinct years ago. It welded itself to the battery case. My habit then was to keep it on the charger and even answer calls with it on the charger at home or office. Not a good habit with some batteries on some devices.

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Stoney62

I doubt leaving them on a charger should affect them very much as charging is regulated and shouldn't cause too much heat. I did have a temp problem a while back and the battery would go from 90% down to nothing in a second. Sprint wanted to charge me $50 for a new battery, but I said no thank you as they were advertising s3s for 49 and I actually took advantage of Sam's 99 cent sale on black Friday. One of theses days I'll move my wife's number from the epic to the touch. But she would hate to lose the keyboard-- she can't quite get the hang of Swype.

Dngrsone

Lithium Ion batteries do not suffer from overcharging like Nickel Metal-Hydride ones do.

They do suffer damage from excessive heat, though; which is why one shouldn't leave their phone in the car or parked right next to the discharge vent of their laptop.