Is it possible to tweak settings so that the battery will only charge up to 90% -95% and then use power adapter to run ?
A friend told me he was able to set such limits on his non-mac PC so I was hoping there would be a way to do it. From reading I have done online it appears this is better than having a 100% battery most of the time.
I have an MBP 13″ 2012 running latest version of OSX ML(10.8.2).
The logic for doing what you want is already hard-coded into the battery and its internal charging circuits. Not only is pretty much every laptop on the market today doing this, but I imagine it’s not something you can change, either. (Commenting from personal experience, I’ve seen this behavior in every laptop I’ve owned or had loaned to me over the past 6 years– Two Dells, two MBPs, and a Lenovo)
When it comes to proper care of laptop batteries these days, the only real advice that an end-user can take is
Store the battery in a cool, dry place when it’s not being used, and don’t heat it up while it’s charging.
Yes, that means you probably don’t want to use the laptop while the battery is charging.
Pretty much every other detail with regards to charging cycles or the implementation thereof have been gone over by experts that study batteries for a living, and are likely already tailored to your battery far better than any generic internet advice will give you.
For anyone coming here in the modern era, there are quite a few updates. For one, as of 10.15.5, Apple is introducing Battery Health Management to do this sort of thing automatically: https://www.slashgear.com/macbook-charging-is-changing-as-macos-gets-smarter-about-batteries-16617057/
If you’re using a Mac on 10.15 Catalina or newer and you’d like more control, the following two projects will let you set peak charge capacity:
If you’re on an older Mac or you’re already an Alfred user, I put together a quick workflow that lets you set either 70% or 100%:
This post also contains a ton more info on battery charging and options.
Finally, especially in the era of USB-C Macs, options abound for less-powerful charger bricks to charge your machine slower for less wear. I personally use a 61w normally, and only use the 87 if I specifically need the power for a heavy workload. Even 30w might be a good choice for charging overnight. But stick with name-brands: many a MacBook has been destroyed by a no-name 87w USB-C supply.