Am I killing my MBP battery?

Barks · 3 Jun 2020 at 06:49

At the risk of sounding overly anxious, is it safe to leave a MBP plugged in for up to a week at a time?

I realise like the iPhone it has smart power management to prolong the battery life but I've noticed over the last few days the battery life % in the monitor starts dropping. Then, the following day it will be back at 100% - it is left on power the whole time. It's behaving as if it isolates the battery which naturally loses charge over a few days - then the MBP just decides to top it back up to 100 which surely can't be good!

Am I worrying about nothing or should I just unplug it and put the battery through the proper cycles it was designed for?

Barks · 3 Jun 2020 at 06:50

Will keep a close eye on this over the next few days:

Charge Information:

Charge Remaining (mAh): 5026

Fully Charged: Yes

Charging: No

Full Charge Capacity (mAh): 5069

Health Information:

Cycle Count: 19

Condition: Normal

Battery Installed: Yes

Amperage (mA): 0

Voltage (mV): 12885

Alpherah · 3 Jun 2020 at 09:24

I don’t recommend it. Coming in a future update is a feature to allow this afaik

Billzz · 3 Jun 2020 at 09:32

Are you running Catalina 10.15.5? If so, there was a new battery health feature added in the energy saver control panel which supposedly helps prolong the battery lifespan by doing just what you describe. I noticed mine was doing it yesterday too - discharged to about 90% then topped itself up. Here's an article that explains better than I can:

https://appleinsider.com/articles/20/04/16/hands-on-macos-10155-battery-health-management

Alpherah · 3 Jun 2020 at 14:33

Billzz said:
Are you running Catalina 10.15.5? If so, there was a new battery health feature added in the energy saver control panel which supposedly helps prolong the battery lifespan by doing just what you describe. I noticed mine was doing it yesterday too - discharged to about 90% then topped itself up. Here's an article that explains better than I can:

https://appleinsider.com/articles/20/04/16/hands-on-macos-10155-battery-health-management

that’s what I was referring to.
Out of the loop being stuck at home

iraiguana · 4 Jun 2020 at 16:09

Laptops are pretty clever and do stop charging when the batteries are at higher state of charge (SOC). You can therefore safely leave them plugged in for awhile. If you really care and are willing to accept the extra effort as a tradeoff for much longer battery health, then you should aim to keep the battery between 20 and 80 %. Satelites and the like can achieve 20 years from their li-ion packs by keeping the batteries between 30 - 70 %. This requires lots of extra effort on your part though, so decide how much you care.

I personally just leave mine plugged in and after the ~ 5 years it takes to fade a noticebly level, I will pay someone to replace the battery for ~ £100 - £150.

hartgeh3 · 13 Jun 2020 at 21:35

I turned that crap off

Feek · 14 Jun 2020 at 10:12

hartgeh3 said:
I turned that crap off

Out of interest, why? It appears to work the same way as the battery management on the phone where it learns your charging patterns and if (for example) you charge overnight and normally get up at 07:00, it only charges to 80% and then pauses charging. Before 07:00, it will top up to 100% so it's not continually sitting at the 100% level. It's doing exactly what's recommended for good battery management.

Barks said:
Am I worrying about nothing or should I just unplug it and put the battery through the proper cycles it was designed for?

It's doing what it's designed for, I'd let it do what it wants.

iraiguana said:
I personally just leave mine plugged in and after the ~ 5 years it takes to fade a noticebly level, I will pay someone to replace the battery for ~ £100 - £150.

My MacBook is now coming up to four years old, Coconut battery is showing it at 88% of the design capacity and it has 203 cycles. I do notice it drains a bit quicker when on battery but when I'm using it on the battery, I'm normally streaming H264 or HEVC video via Plex so it's getting battered.

hartgeh3 · 14 Jun 2020 at 13:30

Never had a single problem before with my iPhones/MacBooks plugged in from day one so don't see the point of it "managing" the battery when it might end up popping up with service battery sooner.