jonnythan:I've been diving with my Terkel since last year and it's always worked perfectly. The canister fits Barry Miller's 9 ah battery, which you can get from ENR Technical (I think that's their name) for $150 or so.
In any case, while the thing is well built and solid, if I were buying now I'd in all likelihood get a Barry Miller light right now. The Terkel focus can't be adjusted underwater, and the spot isn't very tight. It certainly does do the job and it's very tough, however.
You want to get a miller light?
Sorry.