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 ...

For best results, always use a new 9V battery to power the memory saver. First, determine the positive and negative terminals. Then remove the negative terminal clamp from the battery post first.

Holding the 9V battery, lightly brush the terminals against any part of the steel wool, then take the battery and your hand away. To get the reaction really going, try blowing gently on the lit wool.

you’ll be able to charge your device faster while it is running and it’s much more efficient, which will give your 9 volt a longer ... connect the positive battery terminal to the 7805 ...