Should I ever let the battery in my four-month old Macbook Air discharge completely (to 0%)?

It would not be bad.

I have heard that completely draining the battery every once in a while can increase battery lifespan (not how long you can go without charging, but how long it takes before the battery must be replaced).

How long is every once in a while?

I let mine go to full dead almost every time. The Apple “genius” told me at least once a month. It’s not suppose to matter but….it can’t hurt it either.

Here’s some heavy reading about how to save battery life.

Every 2–4 weeks is good.

@PhiNotPi: I asked fluther precisely in order to not have to read that article.

@gailcalled Then I’ll read it for you. :)

It basically says that always filling a battery up to 100% is a bad thing to do to conserve battery life unless you are going on a long trip. Filling it up to 80–90% is better.

It also says that the larger the amount that is drained from the battery between charges, the worse it is. This pretty much means that letting it drain down to 50% every single time you use it is a bad idea. It lists 10% drop as best, but recognizes that this is sometimes impractical.

It also states that the colder the temperature, the better. It gives 0 degrees Celsius as the best temperature, but the computers themselves tend to function better at higher temperatures.

Finally, it says that they can fail if not charged and discharged enough.

“the larger the amount that is drained from the battery between charges, the worse it is. This pretty much means that letting it drain down to 50% every single time you use it is a bad idea. It lists 10% as best, but recognizes that this is sometimes impractical.”

OK. I charge it only to 80–90% if I can remember to pay attention. I should recharge it when it drops to 70–80% if possible?

10% is best…10% of what? A drop in the charge?

However, every month I should let the battery discharge completely both for its and my health?

I edited my response to say “10% drop”.

I have to admit, there is no clear line as to what is best: It is a bad thing to drain the battery often, but it is a bad thing to not drain it often enough.

@gailcalled So, batteries of this variety have something of a charge “memory”. If you let it get all the way down to 0 (or 10%, but 0 is better), then it remembers that it can get all the way down to 0. But, if it’s constantly only ever going down to, say, 50%, then it only thinks it can go down to 50%, and thus is only 50% the battery you paid for. By letting it go down to 0, and then charging it to 100% on a regular basis, you remind it that it has all this room available.

@Aethelflaed Actually, no. Draining all the way to 10 percent is bad to do on a regular basis. A 10% drop is best.

But, also, it is still a good thing to drain the battery every once in a while to avoid another effect.

I am repeating myself here…sorry…but how long is every once in (not and) a while?

I don’t use the thing daily. It was a expensive mistake; I am sorry I bought it since I really am more comfortable with the desk top and its peripherals.

@gailcalled Apple recommends once a month.

Thank you. Clarity and brevity.

(And thanks for the synopsis of the article. I did look at it, but I began to have flashbacks to college physics courses and had to lie down for a while.)

Here’s a recent article about running the laptop; plugged in or off batteries?

Running the battery to 0% is beneficial, but should always be followed by a full charge.