I'll start this to save clogging up the original thread.

I'm thinking of investing in one of Trout's lights, but have no idea what sort of battery/charger is needed. Presumably it will have to fit in a bottle cage. So what does everyone use, and where to get them? Do they need special connections etc? Any info most welcome.

smudge is a good source of batteries on here – I think he's "worked" with the Trout on some stuff.

http://www.singletrackworld.com/forum/profile/smudge

min requirement imho would be one like this
it would give around 2 hours 20 mins on full power and about 10 hours on low so mix up the useage and it will give you a good night ride .

My prefered carrier for the pack is a camera bag like this one
well it is this one

it fits nicely on a camelbak strap for the helmet light
or a strap around the stem for the bar light.

if you went for a 5200 mah pack then it would be best in a bottle .
again my preference would be 2 of the smaller packs and one charger .
much more versatile and maybe better for the racers .

the Liberator does need a 14.8 li ion pack anything lower will overload the driver and possibly kill it .

yes Smudge is the man for batteries