Thinkpads Forum

The battery in my W510 has been acting up for a while now, maybe a year or so.

The problem is that the battery thinks it still has 100% of it's original capacity, no wear of any kind what so ever.
But the reality is different, once battery charge reaches somewhere in the 40's% charge instantly drops to 10%.

A common problem, I have had it many times before, but discharging and then recharging the battery a few times, would always fix it.
But not this battery, it stubbornly believes it is as good as new.

Seems like this problem:
http://support.lenovo.com/en_US/researc ... MIGR-75737

But my battery is a FRU: 42T4795 so it not supposed to be affected by that problem, and it's not one of the recalled batteries either.

Does anyone know a way of making the battery firmware realize that is has to keep track of battery health?

I have not used my battery a lot, but it has been used from time to time.

It's a Sony battery. From my experience with other Thinkpads, Sony batteries tend to behave this way, at least up to a certain point. I have not found a way to force them to properly recalculate their full charge capacity. Maybe when it loses even more capacity, the number will change, eventually.

Thanks for your reply.

Well, just bad luck again it seems, after two faulty coolers, a defective Gobi 2000, odd optical drive behavior and lettering that wore off two keyboards in a row (took less then a year for that to happen to each keyboard), I guess I had to get the worst battery too, but one that isn't exactly broken.

If/when I decide to get a new battery, is there a vendor you'd recommend? Sanyo? Panasonic?

There's none better than Panasonic.
I have some 9-cell (T6x) batteries from around 2009/2010 which still hold well over 80%.
Some with even more than 400 cycles!

There are some nice Panasonic celled 9 cell batteries here.

Thanks everyone, now I know what to do when I decide to buy a battery.
The one I have now still gives me 1-1.5 hours, decent enough, I can tolerate down to 45 minutes.

It seems my T43p battery is a Panasonic (92P1091) it still has around 75% of it's capacity.
I also have a remarkable A30 battery, it still has over 60% of it's capacity left, a Sanyo (02K6898).