Laptop battery charge decreases while off?

I've never seen this in any laptop before. I had purchased a loptop off of ebay, cleaned up the harddrive, replaced the CPU and BSEL modded. It runs great, no complaints.

Problem i've been finding is, the battery charge decreases if i leave the battery in, laptop off, and off charge.
Example: i left it on the charger while i was using it at work on friday. I shut the laptop down (not suspend, not hibernate, a full shutdown) and put it in my bag. The very next day, around noon (less then 24 hours after it was taken off of charge), I started the laptop up on battery power, and it reported it had 82% battery left.


9 times out of 10, i keep the laptop plugged in, and take the battery out when its charged. The battery holds 100% charge while out of the laptop for even weeks at a time

Why would the laptop drain the battery while its off??

It doesn't happen to mine.

Are you sure your battery was at 100% before you turned it off?

By the way, it is not a good idea to leave 100% charged battery on the laptop while on AC power. The heat of laptop will spread to the battery which will decrease its life span.

MikeyLikesItSI said:

9 times out of 10, i keep the laptop plugged in, and I take the battery out when its charged. The battery holds 100% charge while out of the laptop for even weeks at a time

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I said in the first post that when the battery is fully charged and i keep the laptop on A/C, i remove it to prevent heat damage and overcharging.

I also said in the first post that the laptop had reached 100% full charge on friday and continued to remain on charge for a few hours, thus assuring the 100% battery status.

Are you sure it aint going into standby instead of shutting off...?

Again, i assure you that the laptop was definitly forced to shut down, not hibernate, not standby.

I've left mine off an unplugged for a couple weeks and when booted up the battery was down to like 90%, it is normal for batteries to slowly discharge, but again, slowly. Perhaps in your situation, somewhere in the circuitry there is some power loss even while it is off, perhaps a design or manufacturing flaw in it.

MikeyLikesItSI said:

I said in the first post that when the battery is fully charged and i keep the laptop on A/C, i remove it to prevent heat damage and overcharging.

I also said in the first post that the laptop had reached 100% full charge on friday and continued to remain on charge for a few hours, thus assuring the 100% battery status.

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It shouldn't happen. Is it a used battery?

Mine wouldn't even lose 1% power from Standby. So I don't even do full shut down any more.

JDXNC said:

I've left mine off an unplugged for a couple weeks and when booted up the battery was down to like 90%, it is normal for batteries to slowly discharge, but again, slowly. Perhaps in your situation, somewhere in the circuitry there is some power loss even while it is off, perhaps a design or manufacturing flaw in it.

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This might happen to old batteries. I have two 9-cell Lithium Ion batteries. One of them was at 100% and being stored for like a month before I used it. It was still full.

P.S. I just read some articles that it is the best to leave it at 40% if you plan to store it for a while without using. And keep the temperature low.

OC101 said:

This might happen to old batteries. I have two 9-cell Lithium Ion batteries. One of them was at 100% and being stored for like a month before I used it. It was still full.

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My laptop has one 8 cell and it has been pretty much this way since new.

Here is some good info on Li-ion batteries: http://en.wikipedia.org/wiki/Lithium_ion_battery

At a 100% charge level, a typical Li-ion laptop battery that is full most of the time at 25 degrees Celsius or 77 degrees Fahrenheit will irreversibly lose approximately 20% capacity per year.

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Correct me if I'm wrong, but regardless of on or off, a battery(any) will continually lose charge.

OldSkool said:

Correct me if I'm wrong, but regardless of on or off, a battery(any) will continually lose charge.

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All batteries will lose power, even when not in use, but the drain shouldn't be nearly as quick as the batteries of the OP. Batteries designed for long term storage can have a shelf life of 20 years or more and still function fine.

OldSkool said:

Correct me if I'm wrong, but regardless of on or off, a battery(any) will continually lose charge.

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Yes batteries do have a rate of discharge.

But not 18% in roughly 19 hours. Besides, the battery does not discharge when left disconnected from the laptop.

The MT3705 does not have many bios options at all, could some setting be causing this problem?