Nokia N900 Battery Question (Less Efficient Over Time?) - maemo.org

gohan2091 | # 1 | 2009-12-30, 22:22 | Report

Quick question about the n900 battery. Is it best to charge the n900 when it approaches low battery levels e.g. 10%? or can I charge it at anytime at any level without lowering the efficiency of the battery? I don't know much about batteries but I hear some battery types lose effectiveness the more you recharge and eventually, the battery cannot hold hardly any charge.

What can people tell me about this? Thanks in advance

floffe | # 2 | 2009-12-30, 22:26 | Report

You can charge anytime, in fact Li-Ion batteries like in the N900 prefer not being drained too much or being charged too hard. If you can keep them between 20 and 90% you'll probably get the best life out of them.

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stlpaul | # 3 | 2009-12-30, 22:26 | Report

I think with this type of battery the recommended way is many short charging cycles rather than use it until it's dead, charge it until it is full. In other words, put it on charger whenever possible...

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gohan2091 | # 4 | 2009-12-30, 23:05 | Report

Does it state any of this on their website? (If anyone can remember) Thanks both of you, I appreciate it!

stlpaul | # 5 | 2009-12-30, 23:12 | Report

It's just general lithium-ion battery advice. Also, slower, low-power charges are better. So the AC wall charger which puts out 1200mA an charged the N900 really fast is actually worse for its battery long-term than the day-long USB 500mA recharges. Go figure

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AlexDT | # 6 | 2010-01-19, 00:43 | Report

Originally Posted by floffe View Post

You can charge anytime, in fact Li-Ion batteries like in the N900 prefer not being drained too much or being charged too hard. If you can keep them between 20 and 90% you'll probably get the best life out of them.

I charge when I'm asleep... so this would be bad for my phone???
Cause after 2 hours it's at 97%... till I wake up.

Maybe this is the reason it never gets to 100%??

Renkon | # 7 | 2010-01-19, 00:59 | Report

Maybe do
hal-device bme | grep battery
in x-term and look at

battery.reporting.current (current state)
battery.reporting.last_full (last time charged)
battery.reporting.design (what it should be OOTB)
?
These are mAh. If this is somewhere near (last_full / design) * 100 = 97% this is explaining what it shows.

Mine is at 14% charged with current / design = 187/1250 = 0,149 = 14%
and has a ratio of 1044 / 1250 = 83,52%. I will do a complete recharge and report the results afterwards.

Last edited by Renkon; 2010-01-19 at 01:01.

Cas07 | # 8 | 2010-01-19, 01:02 | Report

More info: http://wiki.maemo.org/Batteries

I dont tend to charge mine until its low (just entered red) as there are a limited number of charge cycles (several hundred) but not entirely sure what defines a charge cycle as you can topup charge without that counting.

Renkon | # 9 | 2010-01-19, 01:05 | Report

Originally Posted by

When the operating time (talk-time and standby time) is noticeably shorter than normal, it is time to buy a new battery.

That's the reason they released the new update. Nokia wants to sell more batteries

Cas07 | # 10 | 2010-01-19, 01:10 | Report

Originally Posted by Renkon View Post

That's the reason they released the new update. Nokia wants to sell more batteries

I know you are probably being sarcastic but im getting waay more time out of mine since update.

Oh and good discussion about battery percentage linked from bottom of battery wiki: https://bugs.maemo.org/show_bug.cgi?id=7636

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