maemo.org - Talk

maemo.org - Talk (https://talk.maemo.org/index.php)
-   Nokia N900 (https://talk.maemo.org/forumdisplay.php?f=44)
-   -   N900 Can't Charge to 100% (https://talk.maemo.org/showthread.php?t=62616)

RenaldoTT 2010-09-20 15:18

N900 Can't Charge to 100%
 
Anyone know the reason why the N900 can't charge up to 100% the furthest I've got it to charge is 96%. I read in a thread Lithium batteries shouldn't be charged to 100% or something like that

niGhT 2010-09-20 17:37

Re: N900 Can't Charge to 100%
 
Its the BME on ur fone which charges your phone upto 97% but if u want to charge it to 100% then i think u will have to stop BME from the xterm while on charging.

lardman 2010-09-20 19:08

Re: N900 Can't Charge to 100%
 
Is your battery old?

You may well find that it quite simply can't be charged to "100%" any more (and 100% is a fairly arbitrary voltage level, and the percentage to voltage curve may well be non-linear depending on what the Nokia engineers decided people would want to see.)

I've no clue where the idea to stop BME has come from; without that running you won't get any battery charging at all (and you'll probably also get an automatic reboot in an attempt to restart it.)

woody14619 2010-09-20 19:40

Re: N900 Can't Charge to 100%
 
Lithium batteries don't ever want to be totally charged or discharged. The effort involved in either is futile.

On the charging side, picture a wall of small boxes about 20 inches cubed. Now randomly throw a bunch of balls (just under 10" diameter) at the wall and try to fill all the cubes up perfectly. That's how a lithium battery charges... Getting it up to 75% is easy, beyond that takes a lot of extra throwing, which builds up heat and wastes energy.

On the other side, discharging it is like pumping water out of a well with a submersible pump. You can get all but that last couple percent out pretty easy. But below that, your pump has to work extra hard, the flow is irregular, and it quickly builds up heat and eventually the pump will fail.

Most devices never tell you a percent. They show you "4 bars" or some such. In that case the break down is usually about 17% per bar, with bars representing >75%, 74%-57%, 56%-39%, 40-23%, and 22-5% being NO bars. If the battery only charges to 92%, the first bar lasts just as long as the others. And as long as its over 75% the user thinks it's "at max".

elie-7 2010-09-20 19:56

Re: N900 Can't Charge to 100%
 
maybe be turning of the phone than charging it while its of will charge it to 100 % but it will loose like 4% (or something like htat, i don't know really ) while its booting up .

shadowjk 2010-09-20 20:04

Re: N900 Can't Charge to 100%
 
It's not a problem with the charger, it's a problem with the battery meter used in maemo5.

flailingmonkey 2010-09-20 20:05

Re: N900 Can't Charge to 100%
 
The number reported isn't all that accurate. Just because 100 has three numbers and 96 has two, don't worry about it, its supposed to give you a general idea of charge, not a highly precise measurement.

On the N900, the BME is not required for charging, but without BME it will charge very very very slowly.

EDIT: woody14619 has a very good explanation if you were interested in the actual charging behavior of lithium batteries.

RenaldoTT 2010-09-20 21:04

Re: N900 Can't Charge to 100%
 
well guys my battery isn't old my phone is 2weeks old so not it aint the bat. i believe d ans with the balls n the wall

scribbles 2010-09-20 22:38

Re: N900 Can't Charge to 100%
 
I've charged to 98% one time, very briefly but normally 97%. If you charge via USB whether it be laptop or A/C your values will differ depending on how long you leave it charging. As you know after awhile it will begin to lose the charge, hence the message given when you unplug after a full charge, "disconnect to save power".

I have an extra battery that I will just leave in for days at a time in the charger and usually on the weekend or whenever I replace the battery, it's always @97%.

RenaldoTT 2010-09-21 01:53

Re: N900 Can't Charge to 100%
 
scribbles I like ur signature with the blackberry blacked out thing lol epic


All times are GMT. The time now is 22:18.

vBulletin® Version 3.8.8