Thinkpads Forum

I remember back in the old days of nickel metal hydride batteries, of telling users to fully discharge and recharge their laptop batteries if they were not holding a charge for very long. Supposedly that would increase their life.

What about the batteries used nowadays? Is it better to fully discharge and recharge them, or should they always remain fully charged?

I'm thinking that any discharge and recharge event will shorten battery life just a hair.

I have heard with lead-acid batteries, you never wanted to discharge them past 70% if possible, as that would shorten its life somewhat.

Try to use the search option about this topic. It had been discussed many times. However, this link should give you sufficient information you need to know about batteries : www.batteryuniversity.com

LiIon batteries don't really have the same sensitivity, in terms of capacitive memory, that the older NiCads had. It was always best to fully cycle a NiCad for optimal lifespan. You don't have to do this with the LiIons that often and, when you do, it is because the battery gauge needs to be recalibrated on the controller for both the battery and the Thinkpad; moreso than just for the overall health of the battery. Having the gauge loose accuracy, if not calibrated in a deep cycle, could mean that you would be using the LiIon battery at non-optimal charging/use settings.

The battery itself doesn't, inherently, require such a deep cycle calibration, but it is good for the lifespan of it anyway because it helps the computer decide when and when not to slow charging and predict the time at which the battery will get full; it also increases the accuracy of the battery gauge, giving you a better operating time on battery.

HTH