I haven’t tested or used every cell out there yet but, if I am using a light at less than 1500 lumens or so and I want a nice long runtime I normally use LG MJ1’s. 10amp 3500mah cells that are so far doing very well for me. I also have a bunch of Samsung 30Q’s and Sony VTC6’s for my more power hungry lights. I bought a boat load of LG M26 10amp 2500mah cells not too long ago for lights that I gift, giveaway, or for the kids lights. They work well too, you just loose some of the runtime. Upside is they are dirt cheap. I think if you stick to any Samsung, LG, Sony, Sanyo, Panasonic, and a few others I am forgetting, and you buy from a reputable seller, you will be more than happy.