dead battery

[jaddle]

They really manage to time this well, don't they? Within a couple of months of the 1-year battery warranty running out on my x60s (bought August 2006), the battery started losing capacity significantly. Last night it was down to under a 25%!

I tried to reset it by running it dry overnight, and now it won't even begin to charge! The computer recognizes that it's attached, but after an hour plugged in, it still says there's no charge on it. Looks like I need to buy a new one.

I don't imagine there's any way this would be covered by the 3-year extra warranty I bought, is there?

[smvp6459]

Try running the Power Manager's battery reset.

[jaddle]

I'm not running windows, unfortunately. Is there any way to do a similar function in linux?

I suppose I could install windows on a spare hard disk... but I'd really rather not...

[ryengineer]

Did you by chance fully deep discharged your battery? which by the way is not a good thing for Li-ion battery.

Besides doing a reset, you should also check whether or not your battery was a part of one of the two Battery recalls by lenovo.

[jaddle]

I did indeed fully discharge - many places say to do that periodically (every 30 charges, or once a month) to recalibrate the battery. I have seen a few others saying not to do it with Li-Ion batteries, though, sometimes on the exact same page! Perhaps in hindsight, I shouldn't have done this, though I was getting a little bit desperate - the battery was down to a quarter of its original capacity before I attempted it.

It's not affected by the recall - I checked that right away. (I wish it was, so I could just get a new one!)

[jaddle]

By the way, if a deep discharge is so bad, why does the power manager do just that when you reset the battery gauge using it?

I did try installing windows onto a spare disk, and trying to reset things, but it didn't do any good. Looks like I'm going to have to order a new battery.

In the meantime, my laptop is very very very light.

[ryengineer]

Full Deep Discharges are good for Ni-MH batteries and not for batteries with Lithium-ion cells.

When Power Manager performs a deep discharge it keeps the charge level to a appropriate percentage.

Some lithium-ion batteries feature an ultra-low voltage cut-off that permanently disconnects the pack if a cell dips below 1.5V. A very deep discharge may cause the formation of copper shunt, which can lead to a partial or total electrical short. The same occurs if the cell is driven into negative polarity and is kept in that state for a while.

Manufacturers rate the lithium-ion battery at an 80% depth of discharge. Repeated full (100%) discharges would lower the specified cycle count. It is therefore recommended to charge lithium-ion more often rather than letting it discharge down too low. Periodic full discharges are not needed because lithium-ion is not affected by memory.

Lithium and lead-based batteries do not require a periodic full discharge. In fact, it is better not to discharge them too deeply but charge them more often. Using a larger battery is one way to reduce the stress on a battery.

Discharge methods quoted from Battery University.