Have 2 batteries - can I choose which first discharges?

I have a t400s with the main battery and the ultrabay battery. The default behavior is to discharge the ultrabay battery first. I found an old thread from 2007 that said you can't configure the main battery to discharge first. Now today, is there yet a way to reverse this?

Thanks

 

As far as I know the Ultrabay will always discharge fully (to 0%) before the main battery gets touched. It's unfortunate, but that's just the way it is.

 

+1

Has been the case in my T61 and X301 as well.

 

Thanks for the replies. I wish there was a way to do this.

 

Yep, and after 20 cycles the Ultrabay battery is down to 50%

 

lol at 20 cycles. My T43's 6 cell cycle count is 242 and still i can squeeze about 3 hours with brightness at 3/7, Max Battery power plan. I have found however from just experience and research the Li-Ion batteries memorize how much it had to charge by each time. So if the batt goes down to 40% and you plug it in then it will remember that and if you keep doing that, the batt capacity does diminish. Even when i am near a plug at home and i was previously on battery, i fully discharge the battery before plugging in. After i plug in i don't take it out till it's fully charged, i always do this, and since i bought this T43 used, i've had it for about 6 months and no decrease in battery life. I do this for my iPod and find it hasn't decreased at all either over 1 year of use.

 

It's good to do that sometimes, but not allways.

The best is cool (0 degrees C) and 40% charge.

I have used my laptop not much last year, and I had the batteries at 40%. They didn't loose next to nothing in capacity. When I charged them to 100% the year before I lost a lot of capacity.

The main batteries are also different from the Ultrabay batteries. The ultrabay batteries are basicly junk, controlled by junk software. No consciene man would discharge a Lithium battery to 0% if he wants to keep the capacity.

My Ultrabay battery is now at 71 cycles and the power manager just adjusted it's readings: only 42% of the design capacity left....
The main batteries are much better.

 

How about inserting the ultrabay battery once you've discharged the main battery to your satisfaction?

 

I just might end up doing that, but I wish Lenovo would implement this through software. It's not ideal to have it hanging out an inch, or have an empty bay.

 

How about Lenovo adding ten lines of code to the Power Manager?

 

Ya, that would be nice if you could control how the batteries discharged. Or even if you could tell it to do part of the time from one battery and part of the time the other...

 

Sorry, that wasn't meant to be sarcastic or anything. Just a practical "workaround."

 

that's what I do esp when I need to swap the six-cell. pull the bay battery out until the machine beeps, then stick it back in and swap the six-cell. then let it burn down.