Re-chargeable batteries are perfectly OK but one needs a bit of discipline in their usage.
Initially they are more expensive to buy and the charger must match the battery type (they can be slightly different) but they may be re-charged hundreds of times if used properly and it only costs pennies to re-charge them.
There are two types , the Nickel Cadmium (NiCD) and Nickel Metal Hydride (NiMH). The NiMH types are more powerful and it?s best to make sure that NiCD batteries are fully discharged before recharging because they suffer from 'memory effect' which means that they last for a shorter time after they?ve been charged.
They don?t last quite as long as ?ordinary? batteries because the voltage is 1.2v (as opposed to 1.5v) but the latest NiMH rechargeable batteries are very good.
They are best for most frequently-used devices such as wireless mice/keyboards, telephone headsets, radios, pagers, cameras, calculators, walkie-talkies, remote controls, torches and toys, etc.
New re-charge batteries may need to be charged before using.
The first charge is important and can take slightly longer.
It?s a good idea to buy two sets of batteries per a device (particularly a camera) and be re-charging one set whilst using another.
They are ideal for children?s torches and toys.
Caveat: Don't use them in Emergency equipment. The voltage of ordinary batteries drops at a predictable rate. Rechargeable batteries remain at a steady rate up until their power is nearly completely discharged and then it drops swiftly.