What should I limit my battery charge level to?

[Broko Fankone]

I don't see a point considering AlDente does the job, tbh. Obviously there is risk in the software but that risk is exponentially larger when you involve a hardware part between the mac and the charger, and I would personally never in a million years take that risk with an expensive machine like the MBP. A software risk is way more manageable. My advice to anyone would be to stick with the software limiter.

As for mobile phones, quite frankly I've been charging my Samsung S8 without a single care (it was plugged in overnight hundreds of times) and am yet to see any noticeable drop in battery life with my usage. The battery usually outlasts the phone as the device becomes obsolete before a real drop occurs. Again, a risk I don't see a huge value in taking. Plus it can also be done with software but it's much harder (like requiring ROOT for android phones and I imagine jailbreak for iphones) and that's still a better option but I just wouldn't bother with a phone at all.

 

[GigabitEthernet]

So been doing this for a few weeks and all was going well until I woke up yesterday and now my MacBook Pro's status bar reads 100% but coconutBattery is saying 56.6% (I limited the battery charge to 60%).

Can anyone help?

 

[BigMcGuire]

So been doing this for a few weeks and all was going well until I woke up yesterday and now my MacBook Pro's status bar reads 100% but coconutBattery is saying 56.6% (I limited the battery charge to 60%).

Can anyone help?

Things I'd do if this happened to me?

1. Give the OS a reboot and see if that resolves it.
2. Run on battery for 15-20 mins and see if that helps anything.
3. Plug in and let it charge to 100%.

One of those 3 should resolve it.

I personally don't set AlDente to anything less than 70% because I've read of the % losing focus. I've never had a problem setting Al Dente to 70%.

 

[oliverpolden]

I read the first and last page of this thread and feel I have valuable information to add but with the caveat that I think a lot of users comments are based on speculation and little knowledge on the actual impact. My comments should still be considered speculation, but hopefully fairly well informed speculation:

• I typically have devices where the batteries are still good after 6+ years or even more, probably due to how I treat my batteries.
• The first rule I go by is not to leave any device at 0% or 100% charge for any length of time. Especially if they are going to sit for a week or more.
• Try to avoid charging when warm - leave a laptop 10-20 minutes before charging from 0%. But charging while warm is probably better than leaving it at 0% for a few days.
• I had a 2016 MacBook Pro that I assumed had some intelligence built in that the battery would be fine if I left it plugged in. After 18 months the battery puffed. So I do not trust the Apple battery management. The feature to limit charge to 80% is better, but still not good enough in my opinion.
• I think it's reasonable to assume 50% charge is the best level to maintain the battery at. Perhaps a bit more if you might leave it a while, say 60% then come back to it at 40%. Remember, 0% and 100% are completely arbitrary (within safety limits) and will be set by the manufacturer to give a good trade off between capacity and battery ageing.
• Charge cycles do age the battery? Up for debate. Would, say, maintaning charge between 30% and 70% be much more ageing than maintaining 50%?
• I believe 80% is still a trade off but probably a sweet spot in terms of charge level and ageing, it literally follows the 80/20 rule, but there's the golden ratio too about 2/3 or 66% (1/1.61=62.5%). (Interesting fact: this is the ratio that credit cards are and is found all over the place in nature). But again, 62.5% is arbitrary on top of arbitrary. The advantage between 70% or even 50% or 60% vs 80% is probably not that significant, but 50% or 60% could be recommended if it's not much of an inconvenience.
• As some people have correctly pointed out, what is the inconvenience of having to maintain a specific percentage worth to you? Under normal usage (together with optimised charging), I would expect a battery to last reasonably well for about 3-4 years. It costs around £200 for a new battery, so you could just not worry about all of this and expect to buy a new battery in 3-4 years if you want to keep the laptop for another say 3-4 years.
• Just remember: a fully charged or fully discharged battery, left at that level, may age significantly in a matter of weeks.

Some of my background in experience with Lithium based batteries:
I fly radio controlled aircraft using "dumb" batteries that rely on external chargers. I have fully discharged a battery in a model that didn't have a BEC (Battery eliminator circuit designed to protect the battery by first limiting power to the motor so you can safely land and then shutting off power to the motor, still hopefully able to safely land as you have control but no thrust). That battery puffed up immediately, and a puffed battery is permanently damaged.
Likewise, I have fully charged batteries, left them for a month, and they all puffed up. However, 100% on an RC battery is probably a higher voltage than 100% on a laptop battery. On that note, 0% on an RC battery is probably also a lower voltage than a laptop battery. Essentially, RC batteries are probably considered more of a consumable than laptop batteries.

 

[Mike Boreham]

• I think it's reasonable to assume 50% charge is the best level to maintain the battery at. Perhaps a bit more if you might leave it a while, say 60% then come back to it at 40%. Remember, 0% and 100% are completely arbitrary (within safety limits) and will be set by the manufacturer to give a good trade off between capacity and battery ageing.

This article says similar, ie that the optimum charge for storing a lithium battery at is 40-50%. I have seen the same elsewhere. On this basis I have Al Dente currently set to 50% max normally on my M1 MBA when they are being used at home.

For a while I owned a Surface Laptop which had a BIOS option to maximise battery life if mostly plugged in. There was no adjustment but it limited max charge to 50%. So Microsoft decided similar.