Battery Aging on M2 MacBook Air

[mslilyelise]

Hi folks. So I'm a little confused by the data I'm getting from my M2 Air. According to system settings, I'm sitting at 90% of battery capacity. I've owned the machine just over a year (October 9th 2022 was when I bought it, and I was the first person to ever use it). I've put less than 50 cycles on the battery since, so I've endeavoured to use it a little more elsewhere than my desk, but the drop in battery capacity has me spooked. I opted to keep AppleCare for another year in case it continues to plummet or requires service. I just ran it through a couple full charge to 5% cycles and back and it actually dropped from 92% to 90%.

The functional battery life appears unchanged. I run it often in Low Power mode because on the go all I'm doing is networking and writing, and it seems to me that it's easily hitting it's 15-18 hour run time like that. I'm just worried the battery is going to take a dive and was wondering if I should be concerned or if I should change up my habits to keep it from dropping further.

Thanks!

 

[jdb8167]

I just ran it through a couple full charge to 5% cycles and back and it actually dropped from 92% to 90%.

Don't do this. It is actually reducing the lifespan of your battery. Keep the battery in the 80% to 20% charged range for optimal battery life. Or, as you note, just keep your AppleCare+ and when the battery goes below 80%, you can get a free replacement from Apple.

FWIW, my M2 MacBook Air purchased July 27, 2022 is at 194 cycles. Apple says the battery health is normal at 93%. Looking at the actual hardware parameters the battery is actually at about 85%. Apple adjusts those parameters for the Battery Health because they fluctuate over time; going up and down a lot but overall they always trend down.

 

[mslilyelise]

Don't do this. It is actually reducing the lifespan of your battery. Keep the battery in the 80% to 20% charged range for optimal battery life. Or, as you note, just keep your AppleCare+ and when the battery goes below 80%, you can get a free replacement from Apple.

FWIW, my M2 MacBook Air purchased July 27, 2022 is at 194 cycles. Apple says the battery health is normal at 93%. Looking at the actual hardware parameters the battery is actually at about 85%. Apple adjusts those parameters for the Battery Health because they fluctuate over time; going up and down a lot but overall they always trend down.

That's good to know! Thanks! I didn't realize doing a full cycle was harmful. Is there a way to get the system to say, hold the charge at 80%, and remind you to plug in at 20? I don't need the machine to last 15+ hours on a charge, usually half a dozen is just fine and that's well within specs. I know macOS tries to manage the charge, holding off charging the last 20% until later for instance, but is there a way to force it to hold at 80? Seems like that would help.

Good to hear about AppleCare. That is one reason I got it, I figured I've never had any MacBook have an actual hardware fault, but a battery is more expensive than a couple years of AC+, so it's more or less just a payment plan for a fresh battery a few years down the road.

 

[jdb8167]

I know macOS tries to manage the charge, holding off charging the last 20% until later for instance, but is there a way to force it to hold at 80? Seems like that would help.

There is third-party software. People seem to like AlDente. I don't use it so I have no recommendation. I'll just replace the battery if necessary.