9V batteries are often found in devices that aren’t used very often. If you use a NiCd rechargeable battery you may find it completely discharged by the time you need it. Capacitors on the other ...

All of the common disposable alkaline batteries from AAA to D are single cells. The exception is the 9v battery which actually has six smaller cells inside of it. [Tom] took a look inside three ...

9V, and even button batteries. So, if you use multiple types in your home devices, you only need a single tester for all of them. (Optional, depending on the model) Set the tester to the correct ...