New battery usage patterns

[edwardaux]

I bought my T42 brand new from IBM about 14 months ago, and have noticed that the battery life is nowhere near as good as it used to be. Looking at my battery state info, I see that my last full charge is 27.45Wh out of a design capacity of 47.52Wh. I guess that explains it!

Unfortunately, I am not affected by the battery recall and I have tried to recondition a couple of times (with little success), so I guess I have to buy a new battery. I figure I may as well buy a 9-cell one and get a bit of extra juice while I am at it... however, I don't want to have a repeat performance in a years time so I am looking to manage my battery a little better.

My usage pattern every day is pretty much:

- Unplug from AC and suspend while I walk to the bus
- Start up on the bus and work on battery for 60-80 minutes
- Suspend until I get to work
- Start up and work on AC all day
- Suspend while I walk to bus
- Start up and work on battery for an 60-80 minutes
- Suspend while I walk home
- Start up and plugged back into AC (where it remains overnight)

Now, I am not sure if all these suspends make any difference (I wouldn't have thought so, but I don't know). Also, probably irrelevant, but I recently switched from Windows to Ubuntu Linux (I am using Gnome Power Manager to manage my battery).

Interestingly, my cycle count is 514!!! I definitely haven't *drained* the battery every day, but maybe using it for 60-80 minutes to/from work each day may go close enough to draining that it increases the cycle count.

Given that I have a long commute during which I would like to be able to work on my laptop, any thoughts on what I can do to extend the life for my new battery?? Is draining it/reconditioning once a month the only option I have? Any advice would be much appreciated. Thanks a lot.

—
edwardaux

[tomh009]

My usage pattern every day is pretty much:

- Unplug from AC and suspend while I walk to the bus
- Start up on the bus and work on battery for 60-80 minutes
- Suspend until I get to work
- Start up and work on AC all day
- Suspend while I walk to bus
- Start up and work on battery for an 60-80 minutes
- Suspend while I walk home
- Start up and plugged back into AC (where it remains overnight)

I do a seemingly random mix of battery and AC operation on my X31 on any given day; typically on AC, but I unplug when I need to be mobile. And with 681 cycles my battery still gets up to 78% of design capacity -- not bad at all!

The one difference could be that your T42 never gets used more than an hour on battery, which really wouldn't drain it below maybe 60-70% battery level (at my guess). My X31's battery gets low quite often, and then I do an occasional (months in between!) reconditioning.

So one thought might be to keep running on battery (if not always, at least fairly frequently) when you get home at night, and only plug in when the battery gets quite low. This is definitely not a scientific theory, but it would give the battery more exercise and hopefully better retain the capacity.

[edwardaux]

The one difference could be that your T42 never gets used more than an hour on battery, which really wouldn't drain it below maybe 60-70% battery level

Maybe this is the key... when I first got it, an hour would leave me with around 50% left. I guess over time, doing this constantly (and rarely discharging fully) caused it to end up in its current state.

Thanks for the feedback.

--
edwardaux