Thinkpads Forum

Every time I switch batteries in this T-61, the 'incoming' battery ignores my custom charge threshold settings.

It always charges to 100%. It's the same when I switch back.
Any ideas of how to get them the same without the full charge?

I suspect these settings might be specific for each battery, but then again I may be wrong,
because after it fully charges (100%), they seem to reset correctly?

Both batteries are genuine lenovo parts (Panasonic 9 Cell).

Thanks - Sorry I wasn't able to figure this out myself. It's probably something simple.

Sorry to bump this, but it's with another question.
More sorry if it's been A & A already.

Since every time I rotate the battery it charges to 100%, is that bad for these batteries?
I've read where a complete discharge is bad, but how about full charging?
So far, I've never let any of these fully discharge.

As an aside, I've an ancient Kodak camera using Lithium batteries equally ancient.
They've been plugged into their 'base' which has kept them (I suspect) fully charged.

They are always fine, and for an untold amount of years now.
But I do realize these batteries are different.

Thanks again Everyone

Every time I switch batteries in this T-61, the 'incoming' battery ignores my custom charge threshold settings.

The threshold settings are actually written to the firmware of the battery by power manager, not stored in the operating system or BIOS itself. Removing a battery from the laptop will automatically reset its firmware and cause it to charge back to the default 100%. There isn't a way to change this behavior (at least not easily).

Since every time I rotate the battery it charges to 100%, is that bad for these batteries?

Yes, keeping batteries charged at 100% for extended periods of time will degrade them faster. If you rarely use your batteries, you can keep them at around 15% to make them last a lot longer.

I've read where a complete discharge is bad, but how about full charging?

Complete discharge will very often decrease the capacity of the battery. Even after a few complete discharges, you will likely kill the cells in the battery (ie. battery % all of a sudden drops from 50% to 35%). Lithium batteries become unstable when they reach < 5%, so don't fully discharge them.

Full charging is fine and won't damage the battery. It will likely only degrade if left charged at 100% for long periods of time.

Thank you very much for your response!

brchan wrote:There isn't a way to change this behavior (at least not easily).

You've peaked my interest. What's the 'not easily' possibility(s)?

I've tried everything I could think of:
I've tried to reset threshold and reboot.
I've tried to reset to default (except I don't really know what default was or is*),
replace battery, shutdown pwrmgr, reboot and then reset the threshold. etc.
Probably did more stuff but I lost track after awhile.

* Whether it's to allow it to use software's auto settings (optimize for battery lifespan)
or set it to 'Always fully charge '. (using PwrMgr version 1.48 which is older, but for some reason,
it worked the best in my customized XP. I use a newer version in W7.**
** Multi booting various OS's .

Thank you again!