07-19-2008, 02:38 PM

Hi,

I just bought a black MacBook 13''. Now, the guidelines on http://www.apple.com/batteries/notebooks.html just tell us that it's good to "keep the juices flowing" and not to keep the Mac "plugged in at all times". Ok, that's not very precise ...

I'm in a situation where I'm able to plug in my MacBook almost all the time. So what I'm wondering is what I should do to maximize the lifespan of my battery.

So here is the question:
Should I charge and discharge my battery in complete cycles, i.e. charge to 100%, unplug and use the battery until it is fully discharged, and then recharge it to 100%, etc. etc.

OR

Should I charge it to about 50%, take out the battery and work on my Mac while it's plugged. Then when I need to use the battery, put it back in, use it until there's like 20% left, then recharge it to around 50% again.

It boils down to this:
Is it best to complete cycles of charge/discharge, or to try and keep the charge around 50% as often as possible?

Thanks

07-19-2008, 04:20 PM

tjodrik,

I think your best bet is to keep your Macbook plugged in and charging most of the time, but then daily use it on battery. I use mine on battery while I'm watching TV or just relaxing away from where I keep my Macbook the rest of the time - maybe 2 or 3 hours a day. I don't try to calculate my percent of time on and off battery.

Also, calibrate the battery about once a month http://support.apple.com/kb/HT1490

That should keep it in good health.

Noel

07-19-2008, 04:52 PM

In other words, of the following two options, no. 2 will make the battery last longer?

1. Remove the battery from the Mac at a charge of 50%. Use it rarely.
2. Constantly charge and discharge the battery at 25%-100%.

In both cases, I would calibrate the battery.

I have some difficulties seeing that no. 2 is better, since Apple gives a lifespan estimate of the battery in terms of how many cycles it has undergone. Doesn't that mean that using the battery constantly will shorten its lifespan compared to using it rarely?

07-19-2008, 05:07 PM

tjodrik,

I can't answer your last question. I almost see that as a hypothetical...

I don't think those 2 that you list are the options because I never check my battery's percentages. I use my machine as I need it, keep it plugged in when I'm not using it in mobility mode, use it in mobility mode maybe 2-3 hours a day, and calibrate the battery about once a month. That's my modus...

So I personally don't see the percentages as a useful figure... if you decide to go that way, fine, but in any case, just enjoy your machine! The battery will follow.

Noel

07-19-2008, 05:11 PM

Yeah I really wouldn't stress over it that much, charge it, use the battery when you want, stay plugged in when you want.