Should you replace your MacBook battery or pay Apple to do it?

It's a tradeoff on comfort and model year-the newer it is, the harder it is to replace.

- GLENN FLEISHMAN

Lithium-ion batteries have terrific properties that have caused a revolution in everything from tiny flashlights to Ford trucks. Yes, you have to take them seriously if they show any sign of having a physical failure, such as swelling or smoking (fave.co/3HTaKw7), but that is fortunately an incredibly rare occurrence relative to the vast number of lithium-ion batteries in use.

Wearing down over time is quite common and can be frustrating as a Mac laptop owner, used to many hours of use, now eking out just a few. Unlike older generations of batteries, Li-ion batteries don't have a memory effect, where incomplete charging can reduce their maximum charge. Rather, the chemical nature of the batteries causes a general depletion over time in how fully you can safely charge them.