> The battery is wearing out a bit, but it started out life with so much runtime that losing a few hours doesn't seem to matter.

this is my exact opposite experience. my M3 Max from 2 years ago now has <2hrs battery life at best. wondering if any experts here can help me figure out what is going on? what should i be expecting?

As others have said, keep the battery in the 80%-30% range. Use the `batt` CLI tool to hard limit your max charge to 80%. Sadly, if you're already down to <2hrs, this might not make sense for you. Also prevent it being exposed to very hot or cold temps (even when not in use)

I type this from an M3 Max 2023 MBP that still has 98% battery health. But admittedly it's only gone through 102 charge cycles in ~2 years.

(use `pmset -g rawbatt` to get cycle count or `system_profiler SPPowerDataType | grep -A3 'Health'` to get health and cycles)

Either your battery was defective or something is using all your battery. Even my 2018 Intel MacBook still lasts 3+ hours on a charge.

Apple will replace the battery for $249 if you choose to. https://support.apple.com/mac-laptops/repair?services=servic...

What is your maximum capacity in Settings > Battery Health? What processes are running with significant CPU? What's the typical temperature of the laptop according to a stats app? (Temperature is a good proxy for general energy use.)

I'm typing this on an M3 Max; its max battery capacity is 88%. I've got some things running (laptop average temp is 50-55C, fans off), screen is half brightness, and it's projected to go from 90% to 0% in five hours. I don't usually baby it enough to test this, but 8-10 hours should be achievable.

My M3 Max can burn through battery much faster than my M1 Max ever could.

And some apps are really inefficient. New Codex app drains my battery. If you are using Codex I recommend minimizing it, since it’s the UI that uses most power.

Charge habits with batteries make a huge difference. If your use pattern is that once per day, you take the device from 100% to 10%, you put a lot more wear on the battery than if it kind of hovers in the 30%-80% range for example, or if it just hangs out nearish top-of-charge all day when you're at your desk.

Hot take: people should get used to, and expect to, replace device batteries 1 or 2 times during the device lifetime. They're the main limiting factor on portable device longevity, and engineers make all kinds of design tradeoffs just to make that 1 battery that the device ships with last long enough to not annoy users. If we could get people used to taking their device in for a battery once every couple of years, we could dramatically reduce device waste, and also unlock functionality that's hidden behind battery-preserving mechanisms.

I set Claude loose on my computer and said “why is my battery life so bad?” and it found an always-running audio subsystem kernel extension (Parrot) which didn’t need to be there and was preventing the CPU from going into low-power states. My battery life got noticeably better when I deleted it.

I’m not even sure how it got installed, possibly when I installed Zoom for an interview once but I don’t know. Point is, at least in one case, AI can help track down battery hogs.

Also check which apps use the energy.