few questions on this a while ago so I thought I would update it.
i bought a Deben TriStar Pro LED lamp off a nice chap on here. lamp only, you can get them direct from Deben lamp only too.
Deben wanted between £90 and £230 for a 4aH up to 22aH battery.
Having only paid £50 for the lamp I was reluctant (and genetically tight) to spend twice that on a battery.
bit of research shows that Lithium battery cells without the fancy case and "fuel gauge" are a 10th of the price if you shop around.
Mine arrived this morning from China.
a 9.8aH Lithium battery with on/off switch, input and output plug and a charger (needs an adapter to fit UK)
Grand price of £27 with free delivery.
now quite frankly for that price I dont care if it only turns out to be a 4aH, its still a bargain,
got ot spliced into the Deben cable and fitted a nice chunky plug between the two.
works a charm, about the size of a King Size packet of cigarettes and slips into any pocket