iStat and MBP battery

[Yixian]

I installed iStat today to check my battery health. This morning, it was 87% after 252 cycles.

This evening, it is still on 252 cycles, but has dropped to 75%....

Wtf is going on? Am I missing something, or will my battery dead by the end of the month...

 

[Nevrsadie]

Try Coconut battery and see if it is the same. Have you calibrated lately?

 

[Yixian]

I'm a noob and wouldn't even know what calibration would mean outside of monitor colours.

This morning iStat says 61% :SSSS And guess what... Coconut says exactly the same thing.

Should I be worried?

Is a drop in 39% acceptable for a battery with 252 cycles? Or do I qualify for a replacement from Apple?

 

[Plumbstone]

It is a good idea not to leave your MBP plugged in all the time as this can cause long term damage to lithium batteries.

Also you should be callibrating at least once a month. To do this fully charge your battery (if you can!) then unplug it and let it run right down until it switches itself to sleep. Plug it back in again and let it recharge fully. don't interupt the discharge or recharge or it won't work properly.

You may find that as you are already experiencing problems you may have to repeat the cycle a few times...

 

[Yixian]

I think I'll go for the replacement, and bare that advice in mind with the new battery.

I've had the MBP pretty much awake/asleep and plugged in constantly for the past month o__O