I bought a set of twin smart lights from Mercers in Freo for $125 last year for the Jarradale 12hr. they have a 6 volt , sealed lead acid battery with 5watt and 10watt wide angle and spot beams. I upgraded the 5watt wide angle to 10watt they were great. I then made my own helmet mounted light using a sealed 12v mr16 halogen 12degree sealed globe, some pvc pipe, a switch and either a sealed lead acid battery(min 4.2amphr) or if you’ve got some dosh rechareable NiMH batteries . A pack of 10AA ,1.2v 1.8amphr will last at least about 1hour 20minutes and are very compact and light. Just make sure you charge them correctly.