Thinkpads Forum

Occasionally, I use my laptop without it being plugged in. But even then, for a fairly short period of time (before bed, etc). But during the day I'm mostly using it plugged in. From what I understand that's bad for the battery life?

If I'm using it several hours a day with it plugged in, what's the best way to set up the battery charging, management, etc?

I have my T60 set up to start charging when the battery level drops below 20% and stop when it reaches 80%. I've read somewhere that it's better than to constantly recharge back to 100% after I use the laptop on battery for a short time.

Once every month or so I drain the battery completely and charge it back to 100% to recalibrate it.

Battery life is measured in number of charge cycles. Therefore, it makes sense to utilize each charge cycle to the maximum, i.e. to take out the maximum possible charge from each charge cycle. Set charge level thresholds to stop charging at 80%. The reason for not charging to 100% is that batteries deteriorate faster when they hold a full charge.
As you don't want the notebook to run out of power when using the battery, set the computer to start charging at a level which is sufficient for your short battery powered sessions. For instance, if you maximally need a 15% charge for one battery powered session, set the notebook to start charging at 15%.

Ok, thanks. Where do I go to change those settings? Because right now I seem to be staying at ~98-99%.

ThinkVantage Power Manager, Battery tab, "battery maintenance" (or whatever the English expression would be). Set customized charge level thresholds.

TTY wrote:ThinkVantage Power Manager, Battery tab, "battery maintenance" (or whatever the English expression would be). Set customized charge level thresholds.

Got it, thanks.

One other quick battery related question. How do I set it up so that I have the battery icon in the tool bar to show how charged it is at all times?

Billmanweh wrote: Got it, thanks.

One other quick battery related question. How do I set it up so that I have the battery icon in the tool bar to show how charged it is at all times?

Right-click on your battery icon, and select 'remaining percentage.'

I should maybe add here that in case one sets Power Manager to stop charging at less than 100%, Power Manager's help system instructs users to charge the battery to 100% nonetheless once every quarter.
The help system also recommends to recalibrate the battery regularly.

what exactly does recalibrating do?

Full discharge, followed by full recharge.

Billmanweh wrote:How do I set it up so that I have the battery icon in the tool bar to show how charged it is at all times?

If you have no battery icon at all in the task bar now: Power Manager, Options tab, set it to show the charge level in the task bar.

Whenever I'm near a wall plug it's plugged in. So... How bad is that for my laptop?

Its not bad for the laptop as a whole, but may be bad for the battery. There are lots of pages that describe the why and how much better than I can (and threads here as well probably), but here are a couple http://www.dansdata.com/gz011.htm http://www.friedbeef.com/top-15-ways-to ... tery-life/ What it boils down to is if your laptop lasts say 5 years (or more or whatever) at some point you will probably be replacing the battery, or you may never notice you need to replace the battery because like many 80% of the time the laptop is plugged in. And yes, 80% is a totally made up number.

TTY wrote:Battery life is measured in number of charge cycles. Therefore, it makes sense to utilize each charge cycle to the maximum, i.e. to take out the maximum possible charge from each charge cycle. .........

Actually, for most cell-chemistries, battery-life is measured in total cycled amp-hours.

In other words, if a given cell-type might be good for 700 cycles to 80% DOD (depth of discharge); it will be good for 1200 cycles to 50% DOD, and 2000 cycles to 20% DOD.

Virtually every cell specification you'll find will give figures similar in pattern to the above.

When you run the numbers, you'll find find that every combination of DOD and cycle-life comes out to about the same total amp-hours passed.

Where this breaks down is in deep cycles; because as you get a cell near to fully discharged, the crystal-structure of the compounds changes enough to begin physically stressing the interfaces within the cell. Also, in lithium chemistries, new and undesirable compounds are formed which begin to 'poison' the cathode....producing cumulative irreversible capacity-loss.

Therefore, it is best not to deeply discharge one's battery....at least, not often.

Doing it a couple times per year is good, because it tends to regenerate the original morphology (crystallite size and shape); which maintains/recovers capacity to some degree.

richard