Thinkpads Forum

My x300 has a 3-cell default battery and a 3-cell bay battery, the system always use my bay battery first, then use the default battery. I was wondering is it possible to adjust the battery priority?

silent200 wrote:My x300 has a 3-cell default battery and a 3-cell bay battery, the system always use my bay battery first, then use the default battery. I was wondering is it possible to adjust the battery priority?

I don't think there is a way however why would you even want to change the battery priority while its on the bay???

No - this has been an issue since the T20. It would be trivial to fix - I don't know why IBM/Lenovo has never done it. It should be a Bios choice.

Bay batteries are very expensive. I also find that they wear poorly (probably due to more heat). Many users would prefer to save them for "emergency backup" once the regular battery is used up.

I take some very long trips with no AC access and I have 2 "regular" batteries and the bay battery. I would like to be able to run one of the regular batteries all the way down, then switch in the other regular battery (while it runs on the bay) without shutting the computer down, but i can't because the bay battery is drained first. I have to leave the bay battery out while I run one of the regular batteries almost all the way down, then put the bay battery in, then switch in the other regular battery. no big deal, just a seemingly unnecessary annoyance. I would also say that, for me, the battery run time is less than indicated in the lenovo literature, and i do keep the screen about 8 clicks less than full brightness.

Only FYI, this has been addressed via system controls on the Linux kernel with tp_smapi, which allows you to manipulate and monitor the Ultrabay and regular battery in many ways, making it trivial to force the regular battery to discharge when the Ultrabay is below x%.