Difficult to say too much about batteries. These are NiMh and will power most products that require AAA bateries. I bought these for use in DECT telephone handsets. You'll need a charger, in a phone that is part of the handset, and then you are up and running. Look after them by discharging from time to time to avoid cell imbalance (the memory effect) and they will last you a long time. Don't open them and dispose with care as the chemicals inside are not too friendly but you are still being 'green' by re-using them so that is another positive. You are unlikely to buy any better batteries.