I've had my H51W now for a week or two and have been using it often. Mainly for jogging, but briefly now and then for misc stuff around the house, in the basement, or running out to the garden to get a tomato when dinner happens to be after dark.
I dont have any eneloops yet, and I know they run best on eneloops. But so far the run times I've experienced are dismall! I dont know if eneloops are just THAT much better or my ZL or cells have something weird going on. I've used mainly the Powerex AA's that came with my Lacross 9009, listed as 2600mAhr. I've gone through 2 or three of them all with very short run times. I usually jog in the M1 (26lumen) setting, and if a car comes I crank it up to full until the car is by. Last week I was only jogging 20-30 minutes each night and maybe 5-10 more minutes of misc usage. I've also been reading for maybe 20 minutes in bed on moonlight mode. One battery wouldnt go into high at all the second day and by then end of the second days run lost M1?!? That was probably barely over an hour of usage and M1 is suppose to be 9hrs on eneloops? The next cell I used lasted longer, but still lost high on the second day (but held in M1 fine).
I suppose I need to do a more scientific test and run it straight on a single mode and time it. I'm just kinda guessing at the runtimes, and had mixed modes during my usage.
I'm just skeptical I guess, but if eneloops last that much longer I'm all for it. Although pricey, I have 4 of the XX ones in my shopping cart on amazon and plan on putting an order through in the next few days.