Radio Control Batteries
Guide: Nimh batteries replaced traditional Nicad batteries some years ago. For most purposes they are interchangable and they are ideal for running Tamiya RC cars.
Size: 1800 / 3000 / 2300 etc refers to the capacity in milliamps - i.e. having a bearing on the run time, the higher the longer. Makes no difference to speed.
Chargers: If you have a PEAK charger you can use most of the batteries (check the upper limit of your charger though). If you have the older 30 minute charger, you are limited to the batteries under 2000 mah. Slow chargers are only really of use up to around 2300 mah too, as they take too long otherwise.