I have a Nex Torch programmable. One AA battery per year at most or recharge by USB if you choose but a regular battery works great. More than enough light and the ability to program different light levels through three switch settings. I have had this light for 4 years and it spent 3 months submerged under a foot of water at the bottom of my nephews well pit and came out unscathed and operating. I have used this thing hard and it still keeps ticking