<font color='#000F22'>Nimh & Nicad require different chargers, or more importantly different charging features. It is possible to use the same charger as long as you switch between battery types. A typical example are the 4AA rapid charge chargers that have a switch on the front for desired battery type.
Most but not all are intelligent chargers that'll fast charge then once charged trickle charge, there'll be a limit say 24 hrs not to damage batteries.
One question to ask yourself is if the current batteries arn't knackered why bother, and are the new batteries compatable with the electrical circuitry. You may find you fry your resister. There's a cost to this which may not be worth it. Use the new batteries to build an unbilical HID.
Gareth
(p.s) I have plans to build a HID, £5 for the plans
