I use unilite prosafes. I have a top of the range hs7 or 8 rechargable usb type that i use at work, gets left on charge each day so no probs there. Then i i ha the one below i believe is the hs6, this takes 3 aaa. Bit steep but are intrinsic safe and pretty waterproof although they are not meantto be submergable. Have been reliable,which you need climbing in confined spaces and being part of a rescue team on the boiler. Had one problem with the first i had, got in touch, company director made arrangements to have it picked up,replaced with new foc and came back with full hard hat fitting kit and some other goodies. So vote here for unilite prosafe range.