If the battery still has the same charge as when it was first used, then you still have a charge. If it isn’t, it needs to be replaced because the battery will stop working if it isn’t.
Do rechargeable batteries ever go bad?
If the battery is regularly used, it can be used for up to seven years. A rechargeable battery that is kept and used can only last two to three years. If you want to prolong the life of your batteries, keep using them.
Why do rechargeable batteries stop working?
A film builds up on the two electrodes of the battery, blocking the movement of the ion. The chemical reaction needed to make the battery work degrades when the electrodes are covered in these materials.
How many years do rechargeable batteries last?
If the average lifespan of a rechargeable battery is four years, you can buy a single battery instead of 10 alkaline batteries. It’s a lot of unneeded e-waste over the course of your life.