After posting the message about losing charger (and thanks for the response, it helped) I did some more research. I pulled the manual from UK website on the C4 light and it said it uses 4 Nicad batteries in the rechargeable pack.

That got me thinking…why couldn’t 4 individual Nicad batteries work same as the battery pack? I had totally forgotten about the NiMH until searching for Nicad batteries. There is a huge advantage using NiMH batteries - they can be charged twice as much and they do not have any memory. The disadvantage is cost. It’s more.

However, the question at hand is this: Can individual rechargeable batteries be used? If so, how about NiMH? This could be the better way to go than the battery pack.

I priced for 8 C batteries (so I would always have a set charged for dives)
NiMH 6000 mAh at $69.98
NiMH 5000 mAh at $53.99
NiMh 3000 mAh at $38.29
NiCd 3500 mAh at $33.99
NiCd 3000 mAh at $29.99

Smart charger + DC cord at $39.99
Rapid charger at $29.99
Universal Charger at $24.99

I do not see any difference between a battery pack vs. rechargeable batteries.