10440 cells are the same size as AAA's (although 3.7v vs 4.5v as I understand it), perhaps they can be wired in parallel?). I wonder if this would give any advantage of NiMh? (3x 1.2v NiMH = 3.6v and 1000mAH capacity vs approx 3x 3.7v li-ion in parallel and about 900-1100mAH capacity).
Still, adpating an external battery pack would be preferred for a handlebar light, but as suggested above for the helmet.
For an external battery pack I was thinking something like this: http://www.batteryspace.com/li-ion18650batterywithwater-proofcoatingrubber37v8800mah3256whtrail-techfemaleplug.aspx
It's 4x 18650's in parallel so only 3.6/3.7v but high capacity (much more than 3x AAA's). I assume the light won't draw more than the battery can handle??
It's just the connection inside the light I'm trying to sort out now (so I can hook up and external power source.
EDIT: Do you guys think that you could safely use 4x 1.2v (NiMH) batteries so that it gives 4.8v to the light? (if you use 3x alkaline you would get 3x 1.5v = 4.5v if it's wired up this way???). I'm asking as I'm thinking of putting a external packing using NiMH batteries instead as I already have a nimh charger for AA batteries (which offer much better capacity).