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Semi-OT: Laptop battery calibrations

Ok, before using a new laptop without power supply I wanted to dutifully calibrate its Li-Ion battery since the manual said so. This routine is part of the Phoenix BIOS. After 8hrs the routine still hung at "Step 1: Battery is being charged - Remaining capacity (%): 89". Drat. Called service and they said not to bother. If I wanted this BIOS routine to run right I may have to "re-flash" the whole drive, losing all data and programs. Weird, I thought a BIOS is in an EEPROM, not on the HD. But he said calibration isn't that important (their ads tout it though). Puzzling.

Isn't occasionally letting the laptop run until it does a low-battery shut-off almost the same as a calibration? IOW, is calibration really needed? My older laptops didn't need any.

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Regards, Joerg

http://www.analogconsultants.com
Reply to
Joerg
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Since cell voltage isnt such a good indication of battery capacity over time, the BIOS uses Amp hours. I guess there is a default Value in the bios, and thats what will be used. Another thing is Li-ion take a few cycles to get to capacity. (this might be the problem) A rule of thumb for Li-ion is to not deep discharge them, it will shorten their life.

Cheers

Reply to
Martin Riddle

A lot of dissatisfied customers complain about battery life issues, so the warranty service folk will ask (require) a full charge/ discharge cycle if you call in with a complaint. It takes all day to do that.

The internal charging circuitry will fail to fully charge the battery in some out-of-calibration scenarios, so the calibration IS important. Apple had some firmware updates, some calibration software (Powerbook Battery Reset), and on recent models, a recommendation to let it fully discharge once in a while. All these things were just to get the calibration correct, and (when I was doing warranty service) I saw each of 'em work successfully. If the alternative is buying another $90 battery, do the calibration.

Reply to
whit3rd

Then it would be even more puzzling why they recommend calibration on a brand new battery. I was told that the BIOS cal routine is to get around the amp-hour thing. An amp-hour totalizer veers off after some cycles since it doesn't account for self-discharge.

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Regards, Joerg

http://www.analogconsultants.com
Reply to
Joerg

Well, I would. But it doesn't work :-(

Could it be that calibration should better be started when the battery is somewhat empty?

--
Regards, Joerg

http://www.analogconsultants.com
Reply to
Joerg

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