At night I had 100% battery, about 20 hours later 90%

[leftisthominid]

Last night around 1 AM I shutdown and put away my computer with a 100% battery. Around 10 PM, I unlocked the computer from my laptop lock. I started up my computer, it reached the login screen, I plugged in the cord, and it said 90%.

This could be a one time thing, I'll test it again tomorrow.

But if it isn't, is this bad?

I have an ASUS N55SF. The ASUS power software has been uninstalled.

[Jonastan]

A lot of the time laptop batteries will drain slowly over time, even though your computer may be off. 10 percent drain in slightly under 24 hours seems fairly normal, I wouldn't be too concerned.

You can improve the life of your battery by conditioning it, this involves letting it drain completely before charging it completely every time

[therealjonnyd]

Was the machine in standby or shutdown (or hibernation)? Lithium batteries shouldn't really drain THAT quickly on their own unless its got something drawing on it.

I'm guessing it's one of the following:
A) it was a surface charge and your battery is tired
B) the machine has some small, constant draw (they all have SOME)
C) the machine was in standby and not fully shutdown.

JD

[leftisthominid]

It was fully off.

I put my computer away at 1 AM. At 9:45 AM, I turned in on (unplugged), it said 97%, and then I shutdown. I locked it back up and went to class. I just got home (5:40 PM) and started it up. It was down to 94%.

So I take it this is not too unusual?

[ramgen]

Originally Posted by Jonastan

A lot of the time laptop batteries will drain slowly over time, even though your computer may be off. 10 percent drain in slightly under 24 hours seems fairly normal, I wouldn't be too concerned.

Do you know what you are talking about???
My laptop battery drains 1% in a few days.


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[Jonastan]

Originally Posted by ramgen

Do you know what you are talking about???
My laptop battery drains 1% in a few days.


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Yes, I do know what I'm talking about. Some laptop brands and models will have inevitable battery drain even when off. Great that your laptop doesn't drain as much, but that's not always the case with every type. If you contact and ask any laptop support, they will tell you that 10% battery draw per day is within spec. Unfortunate yes, a huge problem, no.

[ramgen]

I still can't believe. Have never heard of that before.

So you charge your battery full, leave it aside for 5 days totally off and half of the battery is gone! Sounds crazy to me. There should definitely be a circuit design error somewhere. Li-ION chemistry is not *that* bad for self-drain.


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[leftisthominid]

Right now it says "99% available (plugged in, not charging)"

Early today and yesterday it used to go up to 100%

[leftisthominid]

Between 2 AM and 8 PM it went from 99 to 94 in disuse

[Sxooter]

Does your laptop support the "charge while off" USB ports? If so, can you disable that in the BIOS? Most machines with that will drain the battery even when off slowly...