Thinkpads Forum

Hello,

Should you perform the "Battery Gauge Reset" in the Power Manager program periodically (e.g. once every 3 months)?

I performed it and after the reset the Full Charge capacity went UP from ~67 wh (45 cycles, 1 year old) to ~74 wh. The design capacity is ~75 wh. On the face of it, this would seem like good news. The only odd thing I noticed is that at 100% charge the remaining capacity was less than the full charge capacity. I would expect those 2 to be the same at a 100% charge.

Manish
X61s 7668-CTO
Vista Ultimate

Wondering what implication this has?

No, don´t try a reset.

Please take a look here.
http://forums.lenovo.com/lnv/board/mess ... 368#M23730.

For powermanager settings, take also a look here:
http://forums.lenovo.com/lnv/board/mess ... 3410#M2341

The lenono forum members sounds confused by what "fully discharging" a battery means, versus fully discharging a computer battery pack.

The electronic controls in most computer battery packs are charge congrol computers in their own right, they will not allow a battery pack to be fully discharged. You would have to but open the pack and then connect a light bulb or other resistance across the internal batteries in order to "fully" discharge them. The internal charge control computer will not allow a fully discharge.

Now, if you leave the pack uncharged on the shelf for a year to two--it might leak down to a full discharge also. Or if the internal charge controller is defective, etc.

But it sounds like the two "sides" are really taling abouit wo different things. You cannot discharge a computer battery all the way simply by leaving it on--it is NOT a flashlight, there's a computer in the battery pack that won't allow this to happen.

LiOn battteries probably have the highest defect rate of any battery type. They short out from internal problems--which sometimes just kills them, sometimes sets them on fire, sometimes explosively.

There's no way to calibrate "how much energy is left in this battery" without doing a "full cycle" on it, and unfortunately if you do that you will CONSUME AND WASTE one full cycle, out of the 500 or so that the battery has. So by all means calibrate the battery--but not too frequently.