How do you maximize the cycle count of your battery?
There seems to be a debate between:
- Leave plugged in 24/7 but do a full cycle once a month
- Charge to ~100%, drain to ~10%, repeat.
NOTE: Taking your battery out is bad
Which method is better and why? How much of a difference does it really make?
Here are some of the better sources I've found about battery behavior so far. Even still I feel they don't conclusively answer the question above. See my elaborations below:
Elaborating on Option 1
Now IF Apple engineers were smart and optimized for AC draw when plugged in to not use up your charge cycles, then it seem logical to assume that you are using effectively none of your 1000 charge cycles while plugged in. If that's the case, it would seem that the LiPo drop from holding at 100% would be vastly outweighed by the fact you're not using any charge cycles.
However, this is a purely speculative assumption and I could find no evidence to either confirm or deny.
If this is NOT true, and the AC adapter only goes to charging the battery, then there would be no difference. Your battery would drain to 99%, then back up to 100%, then back down to 99%, etc. Those micro-charge cycles would add up at the same rate as 100% -> 0% -> 100%, and you would get no gain. In this case the negative effect of holding LiPo batteries at 100% would outweigh everything else.
Elaborating on Option 2
There are lots of good reasons why Option 2 is the way it is:
- Because of known LiPo chemistry issues, holding a 100% charge for a long time causes the battery to degrade
- Apple specifically recommends not to leave it plugged in all the time on their website
- Draining a battery all the way to zero all the time is bad for the cell (Which is why ~10% is used)
- Heat is a killer, and when plugged in AND charging, you get extra heat that causes damage.
There are a couple reasons why I'm challenging Option 2:
- It seems silly that the most intuitive use case for thousands of people that use their macs as primary computers is wrong.
- If the hypothesis in option 1 is true, you're just burning unnecessarily through your finite charge cycles.
- It's a pain to have to remember to keep plugging in and plugging out and be worried about whether or not your device is plugged in.