Another battery question

[gte204i]

I don't want to recharge my T42 battery until it is below 30%. If I am plugged in, I still want to use power from the outlet, and just not recharge the battery yet. Right now, IBM has that threshold set at 95%, I think. The problem is that I will be plugged in for some period of time, unplugged for a short period of time (<1 hour) and then plugged back in. This will lead to short disharge/recharge cycles (100% -> 80% -> 100% ...).

To avoid this, I remove the battery when I plug in. Is there a way to change that 95% threshold to some other number? Any other tips to avoid this problem?

[awolfe63]

Lithium Ion batteries are designed to withstand short charge cycles. That's one of the reasons laptop guys use them. Just charge it whenever you plug in. It will last 1-2 years (80-100 full charge equivalents) like they all do.

[gte204i]

I thought that even though lithium batteries aren't supposed to have any memory, it is still recommended that you discharge almost completely. Maybe I just read that about the first time you use it.

When you say 80-100 full cycles, do you mean that 5 20% cycles is equivalent to 1 full cycle?

[awolfe63]

Basically - yes. That's how IBM counts them.

Some Li-Ion manufacturers recommend that you do a full discharge/charge once a month to maintain the best capacity.

[Chun-Yu]

I thought that even though lithium batteries aren't supposed to have any memory, it is still recommended that you discharge almost completely. Maybe I just read that about the first time you use it.

No, it's actually the exact opposite. From http://www.batteryuniversity.com/parttwo-34.htm - "The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery."

[JaimitoBond]

yeah, deep cycles seem to be for the battery meter, not the battery itself. I find that deep cycles reduced my battery's max charge capacity.