If you want to keep your old system you could try this guyhttp://www.mtbbatteries.co.uk/
He posts a bit on STW, seems well respected. AFAIK he could supply batteries for your existing lights. I also like the look of the new light he has coming.
Thanks, but I think keeping the old Lumicycle lamps might be taking retro too far - you'll be expecting me to use cantis and clips next!
He does sound as though he knows what he's talking about, and I suppose it's quite a good business ploy to establish credibility on a site like STW. Having said that, I noticed that some of the text on his site was in pigeon English and looked as though it was cut and pasted from what his Chinese supplier had written. I guess we're just paying people like him and Torchy to sort the wheat from the chaff for us in what's coming out of China, because I expect some of the really cheap stuff is very dodgy.
I noticed on another thread that cchris2lou had recommended some £28 light as all you'd ever need, but the instructions said always charge the batteries in a safe place, never overcharge the battery and never leave the battery charger unattended, which sounds to me like all you need to burn your house down!