Charge limiting to extend lithium ion battery life
Battery lifespans are affected by many factors including the ambient temperature they're run in, the speed they're recharged at, and the number of times they're discharged and recharged which is sometimes referred to as the number of cycles that a battery has been through or has capacity for.
By extending the lifespan of your devices you can save yourself money, reduce e-waste, and contribute to reducing demand for limited resources which motivates corporations to contribute to conflict and death in foreign countries.
There are a few things you can do to extend your device's battery life:
- Keep batteries at cool temperatures
- Examples: avoid leaving devices in the sun outside, in a hot car, etc.
- Charge the battery up to 80% and do not allow the state of charge (the percentage your battery is at) to fall below 30% of it's available capacity.
- Don't fast charge or otherwise overwork your battery if you don't have to.
The second point can be hard to manage manually, and the point of this post is to provide an overview of software that will make sure your device only charges to 80% rather than to 100%.
How it works
(very simplified)
This graphic from Battery University's page on what causes capacity loss represents the unused portion of the battery capacity as “rock content” which increases as the battery ages. As a result the battery will take less time to charge, but require charging more and more frequently until it can no longer be useful for energy storage.
By limiting the total charge to 80% we're effectively keeping a buffer of available capacity within the battery. Here are some resources to help you do this with a few common types of devices.
Phones
For iPhones, I have not been able to find a non-Apple solution to limit my battery charge to 80%, so I must direct you to Apple's in house solutions. For iPhones older than iPhone 15, the best option is to ensure battery optimization is enabled. For iPhone 15 and newer, I'd highly recommend going to Settings > Battery > Charging Optimization and setting the limit to 80%.
I'm glad Apple added the option, but also am disappointed it's locked to the newer phone models.
Above is a screenshot of my iPhone where we can see that the maximum capacity is 86% and optimized battery charging is enabled. This is available on iOS via the Settings app > Battery > Battery Health.
Note: The following Android options I have not investigated or been able to verify myself, but am providing to include as many resources as I can!
For Android phones, Google does have a dedicated support article on which settings to use for battery optimization and specific manufacturers may have their own options available for battery longevity, so this is much more specific to model and make.
Meanwhile the Play store is riddled with third party options, but I don't have the means to test them in a way that I can recommend any one application. For these apps to work they require low level permissions on your phone, so be careful! This article from Gadgets to Use has some recommendations of how you might go about this.
Laptops
This is my laptop after setting a battery limit. The recharge limiting only is in effect when the laptop is on because it needs to be running the application that imposes the limit on the system, so if you do install one of these applications make sure to only charge your laptop while it is running to ensure it will only charge up to 80%.
This also applies if you're using a dock to charge your laptop and hook it up to peripherals such as a monitor, so if you power down your laptop also unplug it!
I've only tested this with an Apple machine; if this caveat varies depending on OS I will update this post when I learn that, but I think this practice is a good general rule of thumb for now.
If your laptop is an Apple machine, Gadgets to Use has an in depth guide on a few options. I'd recommend using either AlDente charge limiter by AppHouseKitchen or at the very least ensuring Apple's battery optimization is enabled on your device.
Note: The following Laptop options I have not investigated or been able to verify myself, but am providing to include as many resources as I can!
For laptops running Windows, there are different options depending on your Windows version and the manufacturer of your laptop. Windows Report has an article with a few common manufacturers which will allow you to not need to install a third party application. If none of those solutions work for you, they also have recommendations for third party battery limiting applications for Windows.
Linux laptops similarly have different options depending on the machine and distro being used, but this article on Baeldung.com provides some instructions for a few different tools, and their second suggestion is TLP which I have read about a few times and seen recommended on forums as a general solution.
Resources for other devices
- Apple has a page on battery optimization and storage that applies to most of their devices
- If you drive an Electric Vehicle, best practice is to ensure your car settings are limited to charge to 80% maximum. This varies by manufacturer but is a standard option.