Long Term Laptop Battery Test

techsupport1307 · 20 Sep 2012

Been suspicious of laptop batteries performance for many years. Purchased Dell Studio17 and booted first time on 8/26/2010. Performed the recommendations for charging the battery and a 2 week break in period. Performed a discharge calibration and battery lasted 3.5 hours. After 10 months started receiving battery warning messages. Messages have progressively become more dire. On 8/26/2012 at exactly 8 A.M. received the dreaded "Battery Dead Will Not Charge" message. Installed third party battery manager, uninstalled the ACPI, and booted without the battery. Set all battery notifications, actions, and reserves to zero. Shut down laptop and charged battery overnight. Next morning booted, installed ACPI, inserted battery, unplugged power and started stop watch.

Battery monitor sez (sic) zero charge and battery lasts for 3.5 hours.

As I have suspected, the ACPI is calendar driven, not physical calibration of the battery. All of its warnings are bogus.

Now I am trying to figure out how to wipe clean the ACPI to reset the monitoring for the specific battery. Advice will be appreciated.

TVeblen · 20 Sep 2012

The battery may be defective. Modern laptop batteries have a chip inside them that reports their condition. If that chip is damaged or defective it will not report correctly.
You might want to check that possibility before playing with your critical systems.

Inner Workings of a Smart Battery – Battery University

bobafetthotmail · 21 Sep 2012

technically, the chip in the battery is more a calendar than anything else as well (it counts the number of discharges/recharges and based on that reports as battery status what the manufacturer told it to). So it can lock up the battery and say "battery dead" even if in fact it isn't.
People (read unwashed geeks) have hacked this chip (low-level programming wizardry) and prolonged lifespan.

Weirdly, non-branded batteries seem to fare better in this respect, as their controllers usually don't have this "feature".

Still, while lithium batteries do actually degrade with time, 10 months are a bit to friggin fast. If it does again the same trick I'd suspect something is malfunctioning.