My T60 6 cell battery drains even though it is always plugged in??

I always leave my laptop plugged in to preserve the battery since Lion batteries has limited recharge cycles. I set me battery to the "optimize for battery lifespan."

Does this setting allow the battery to discharge a bit even though it is plugged in?

Just wondering what the deal is.

Thanks!

 

probably - I believe my T43 recharges if it hits 95% capacity. I'd guess they don't trickle-charge the batteries for temperature reasons or something.

 

Yes. A battery will discharge slowly when not in use. When you set to "optimize for lifespan", you are telling it not to top off the battery all the time to cut down on the number of charge cycles, increasing lifespan. For example...

Over the course of a few days/weeks, your battery will slowly drain by a few percent just by not using it. This would happen even if the battery was removed from the laptop. Since you've set it to "optimize", the thinkpad may decide to start charging it again when the battery level reaches 90 or 95% for example. This is better for the battery than sending it a charge every time the level drops to 99%. Make sense?

 

Makes sense...here's my only issue...my R40 never did that. Meaning, I always plugged it in and it never ran the battery down. Plus, when I say it runs down, we are talking like overnight, not days or months.

So...I get what you are saying, but should my battery really run down overnight...or is the battery setting *causing* it to run down?

 

dumb question...where exactly is the optimize for lifespan option located?

 

The battery will discharge regardless of whether it's plugged in or not. That is the nature of Li-Ion batteries.

Please read through the battery guide for more information on the subject. There are some tips to prolonging the lifespan of your battery there.

 

How much does it run down exactly? I don't think you should be losing more than a percent or two a day. Mine read 100% all day yesterday and today it says 99%.

 

[The battery will discharge regardless of whether it's plugged in or not. That is "the nature of Li-Ion batteries."]

It seems that you know a bit about Li-Ion batts. So my question is this, why didn't my R40 exhibit this same behavior? I am using my T60 the same exact way as my R40 and the battery NEVER drained unless I used it while unplugged. (I read the link you posted and am familiar with the battery university).

 

My guess is that the R40 didn't have the same settings as your T60 does. Perhaps it topped the battery off constantly, rather than intermittently doing trickle-charges like the T60. The R40's battery most definitely had a discharge rate when not in use, though. It's physically impossible for a battery to hold a charge and not lose any of it.

I wouldn't worry about it too much, as the trickle-charges will not take too much from your battery's overall lifespan. Just make sure to calibrate regularly or put your battery into prolonged storage.

 

My T60 stays between 96 and 99% usually. I have it set to manage itself for maximum battery life. I would agree with Chris that it's not something to concern yourself too much about.

 

Sounds good. Thanks for the help. I have had good luck with most of my Li-Ion batteries in my laptops, cell phones, etc., by following the rules. But this was new to me.

Thanks again.