Headtorch cree with single screw access battery???

vci380
vci380 Posts: 17
edited October 2016 in MTB buying advice
I'm after a new cree type head torch for bombing through the woods on these soon to be dark nights. I've had the type with the double battery pack on the back before but accessing that can be a pain if you've tie wrapped it to your helmet etc and often the charging ports go faulty on them.
What I want is a decent lumen light on the front of my helmet with a single ultrafire type battery pack on the back with a screw top battery access. Then I'll just take a handful of batteries out with me and as one goes simply drop another in. We're usually out for around 4 hours so its only really one swap a ride so its no biggy.
Any suggestions on what you've used or links to sites would be appreciated. I also want to keep this sub £20.

Thanks guys