• After 15+ years, we've made a big change: Android Forums is now Early Bird Club. Learn more here.

Android Phone help


May 27, 2012
So I bought and android phone and got 30% battery with it..I waited the phone to turn off and I charged it for the first time for 11 hours,and when I was checking it said battery is full,then I turned on te phone but it said 92%,and then I left it to charge to 100% why can't he charge to 100% when turned off??thanks in advance
Greeetings alduin400,

It's probably true that the battery does get better after a few charge calibrations, but you should also be aware about how the charging works.

A battery charges to 100%, then protection circuits in the battery shut off the current being supplied, and the battery begins to discharge. When the charge level drops to about 91-92%, the current is applied again and the process begins anew.

The full charge or 100% sign that you see while the phone is still plugged in, is just the residual signal shown when the battery attained its full charge. When you unplug it, the <100% number that is usually shown is the actual charge that the battery has a the present moment.

People freak out and think that they have a battery issue when this happens, this is usually not true. You have no actual way of knowing when a full charge was achieved, unless your watching the battery constantly.

If your watching the battery charge and it can't get above 97%, then you might want to look into possible battery issues.

Hope this helps.
  • Like
Reactions: ocnbrze
Upvote 0
I like to calibrate my battery once a month or so, here's what i like to do :

With phone on, fully charge battery, unplug charger, turn phone off and plug charger back in, takes anywhere from 15 minutes to an hour, once fully charged, unplug charger, turn phone on,once it's fully booted, wait 2minutes turn phone off and plug charger in again, wait til fully charged again, couple minutes, unplug, ... this is how i calibrate my battery, works for me!

Upvote 0
TMML hit it the nail on the head. This is exactly how lithium-ion batteries gets charged. these batteries cannot handle overcharge so the fail safe chip in the battery shuts the current off and thus it starts to discharge. when the levels get to a certain level then the charge is again reapplied.

here is an article for you to checkout:
Charging Lithium-Ion Batteries

and chanchan05 is also right in that powering off the phone to charge it makes the phone work harder upon booting up. however, a weekly powering off will help the phone. this will clear cache and temp files and thus speeding the phone up.
  • Like
Reactions: badblue1
Upvote 0


We've been tracking upcoming products and ranking the best tech since 2007. Thanks for trusting our opinion: we get rewarded through affiliate links that earn us a commission and we invite you to learn more about us.