Dead battery starts off with 47% charge

[Mugen Power]

I usually run my phone until it dies and then swap out a spare battery but yesterday and today, I decided to plug the phone in after it completely died instead of swapping the battery out. The moment I plugged it in and turned it on, it showed 47% battery life. What gives?

 

[Crashumbc]

I usually run my phone until it dies and then swap out a spare battery but yesterday and today, I decided to plug the phone in after it completely died instead of swapping the battery out. The moment I plugged it in and turned it on, it showed 47% battery life. What gives?

Not sure that pretty weird...

Note: LiIon batteries, do not need to be fully discharged like the NiCad batteries. In fact, most of what I've read over the years indicates it is bad to do so with them.


http://www.techrepublic.com/blog/helpdesk/the-care-and-feeding-of-li-ion-batteries/124

http://electronics.howstuffworks.com/everyday-tech/lithium-ion-battery.htm

 

[AntimonyER]

I have had this happen once, in a slightly different circumstance. I was down to about 10% battery, so I turned my phone off. When I turned it back on, it was at 41%. I think it is just a reporting glitch.

 

[Mugen Power]

Not sure that pretty weird...

Note: LiIon batteries, do not need to be fully discharged like the NiCad batteries. In fact, most of what I've read over the years indicates it is bad to do so with them.


The care and feeding of Li-Ion batteries | TechRepublic

HowStuffWorks "How Lithium-ion Batteries Work"

Thanks, I'm aware of the charging nuances with these types of batteries but I usually don't have a charger with me nor am in the same spot for long so it's more convenient for me to use one battery as long as possible and then swap it out for another.

 

[bradyapba]

Thats been a standard droid issue for a while now. My droid 2, my x2, and now the Nexus is doing it. I dont know which is right, the lower number or the higher number, so I usually end up leaving it in the charger extra long, just in case.

 

[Mugen Power]

Thats been a standard droid issue for a while now. My droid 2, my x2, and now the Nexus is doing it. I dont know which is right, the lower number or the higher number, so I usually end up leaving it in the charger extra long, just in case.

I never noticed it with my OG Droid or Bionic, they always started up charging with a "red" or empty battery indicator. This phone will "correctly" show the battery indicator at the half mark.

 

[bradyapba]

Yeah, I didnt say all droids, but I know its a common issue on a lot of them. As a family we have owned 5 different model droids, it happen on 4 of them.

 

[dhworph]

I just started a thread in the general galaxy nexus section for a similar issue. My battery wasn't dead, but after manually rebooting it at 9% and plugging in my car charger, it was at 49% after the timespan of a reboot.

So there is definitely something weird about how the battery % is read...

 

[ZachMob]

I noticed it happens to other Android phones too.

My theory is that the act of charging the battery inflates the voltage reading which makes it appear to have more charge than it does. In some circumstances, it will screw up the algorithm that calculates battery %.

 

[Tim K]

Yep. Used to happen randomly on my Droid. Battery would suddenly drop <10% from like 50%. If you power cycled or plugged it in it would go back to 50%. Its some weird battery glitch that seems common to Android devices.