Having your own hair trimmer makes it simple to keep your beard and hair line nice and neat without running to the barber shop often. While there are several different types of hair trimmers on the market, there is one universal reason for why they all stop working: dead batteries. Although it is recommended to check and change the battery every 30 days, it is very easy to forget to do this. Luckily, it is also very easy to replace the battery in a hair trimmer.

Remove the door to the casing outside the battery housing. Some doors are held in place with a screw, so unscrew it before trying to pry it open.

Remove the old battery (or batteries) and dispose of it properly. If you are using a rechargeable battery, then put it in the recharger and allow it to recharge.

Place the new, replacement battery in the housing. Pay attention to the direction on the diagram that is printed in the housing. This will show you the correct placement of the battery, so that the positive position of the battery is facing the right way.

Replace the door back on the trimmer and check it. If nothing happens, you may have put the battery in the wrong way. Remove the door and check the position of the battery. Also, ensure the battery is pushed in all the way. Sometimes there is a click when the battery is fitted firmly in place.