choosing a battery for X40

[red.dot.fan]

I recently 'upgraded' from a 600x to X40... though I'm relatively impressed with the battery life on the X40, I'm trying to figure out what the best option is for extending the battery life. I'm aware that there is a battery that fits in the dock, the one that fits in the docking port, and an 8 cell.

I would just like to get some opinions on the options. I'm not impressed with the option of the ultrabay slim battery, because If I had wanted to carry the ultrabase around with me, I wouldn't have opted for an ultraportable computer. I'm also not sure that I'm interested in adding the bulk of the extended life or 8 cell batteries... maybe it would be best to just get a spare 4 cell?

aside from appearance though, I'm wondering how well the options work

[zaqrack]

I have mine with a 8cell (actually as far as I know it is 9), and never had problems with the size nor the weight. It's still below the x31/32, and even though my battery has only 80% of its original capacity, I can still get a practical usable 5 hours battery time with wifi off and some NHC usage.

Guess it all depends on how much do you need the extra time. I need it for my travels and love it.

[underclocker]

Welcome to the forum. Great laptop choice, too!

I have an X40 with a 4 cell, 8 cell, 4 cell extended that snaps onto the bottom and the UltraBase with a 3 cell UltraBay Slim. I've got them all.

It comes down to two things, 1) weight and 2) battery life.

The 4 cell lasts about 2 hours (rated at 3.5), the 8 cell lasts about 6 hours (rated at 7.5), the extended lasts about 2 hours (rated at 3 or 3.5) and the 3 cell lasts about 1.5 hours (not sure on rating).

You can only use a maximum of two at once. For maximum runtime, use the extended plus the 8 cell, you'll be good for 8+ hours.

I usually keep the 4 cell installed and if I travel far, I bring along the 8 cell. The other configurations don't really work for me.

The 8 cell battery is the only outstanding one of the bunch, but it is heavy. If I could only have the 4 cell and one spare, I'd take the 8 cell for sure.

[mikeh]

Has anybody tried replacing the Li-Ion cells in the X40?
The cylindrical 18650 cells in the extended part are easy to obtain (~$5 each),
but I don't know about the rectangular cells.
Googling shows that some laptop models do well, with the controller chip learning the new bigger capacity over a few cycles.
But other models will refuse to charge, just like those printer ink-cartridges with the chip to stop refilling. Anyone tried an X40?