Help 0% to 99% charge fast, 99% to 100% slow...

[CloudyTrain]

Title says it all. My battery charges quickly to 99% and then takes a long time to get to 100%. I don't know how long this has happened because I just installed a battery widget the other day. I probably have 7-8 cycles on the battery and am not rooted.

The battery charge indicated via menu<settings<etc., shows full 100% bars for the battery, but the indicator in the notification bar still shows its charging and the widget shows its still at 99%.

This is probably the 2nd time I've noticed this.

Anyone else experience this or have thoughts?

 

[jcnyc]

Yes i've definitely noticed this as well. Not sure whether it's just how it's suppsoed to be or a software issue but it definitely happens every time. Makes me think perhaps when it reaches 99% it is really still at 90%

 

[bluenik25]

Just an educated guess, but I believe this is a smart function of the battery/Phone to keep from overcharging the battery and reducing its life.

 

[WA_Bob]

Just an educated guess, but I believe this is a smart function of the battery/Phone to keep from overcharging the battery and reducing its life.

That's what I've read in other places with regards to the Lithium Ion batteries used these days. All things considered, it's not going to make a noticeable difference to you in terms of how much usage/ time you get out of the battery. I do agree it's annoying, however!

 

[CloudyTrain]

Okay, cool. Glad to hear others are having this issue and that there might actually be a legitimate reason for this to happen. Thanks for taking the time to respond.

 

[skinien]

Just an educated guess, but I believe this is a smart function of the battery/Phone to keep from overcharging the battery and reducing its life.

This is correct. I believe what's happening is the phone does a "rapid" charge to a certain capacity, then does a "trickle" charge from this capacity to 100%. When it reaches 100%, it stops charging and won't charge again until it drops down to 95% (just throwing out a number).

Otherwise, while the phone is on the charger over night, it would constantly go from 99 to 100, back to 99 then to 100, and so on. The cells have a lifespan so this would definitely decrease the life of the battery. The "trickle" charge increases the time it takes to get from 95 - 100, so your not charging/discharging so many times when plugged in for a long period of time.

This is also why you may unplug your phone from the charger to see that it suddenly drops to 97%.