What does the mAh mean in lithium-ion batteries?
The mAh stands for "milliamp." The mAh is basically the capacity of the battery so the higher the number of mAh, the longer the runtime will be before having to recharge your batteries. It's important to make sure you're using the correct size lithium-ion battery. For example, most flashlights that take 21700 batteries will not be compatible with 26650 batteries due to their size difference.