The way I see it, someone at FF sent this light to me knowing the battery tube tolerance is faulty. Too much of a coincidence that they forget the batteries and that the batteries won't even fit. I can't figure out if it is the cage or the actual tube that is the problem, but I'm thinking maybe the cage is not allowing the batteries to come close enough together to fit in the tube.
Try sliding the batteries in without the cage.
On the plus side, maybe FF can send a replacement battery tube with batteries inside. They just need to toss some aluminum caps on both ends and it will be sealed really well for shipping.
Sorry, I missed that. No problem, slides in smoothly without the cage. I thought about loosening the cage screws, but then that really isn't a good idea either.
There are 5 screws total… maybe you can adjust by loosing it little bit… . give it a try…
I thought about that, but having some screws loose doesn't seem like it would be good to do.
Ok, maybe not a bad idea after all. I put the cage under a strong light and I can see some of the cage tubes warping inwards, which would be enough to not all the batteries to sit tight with each other. Going to unscrew and rotate them to see if I can get a tighter fit.
It is hard to explain… hold the right side of the carrier and hold the left side of the carrier at the same time… both sides must able to move or twist…
I observed 2 black pole should be tight and one black pole should loose freely…
You can adjust it using your hand… can you try that method?
Okay, then that means the cage is not letting the batteries touch each other. The battery tube seems to be okay. It’s something with the carrier.
Try shining a light to see if you can get the batteries all touching side by side. I think you are on the right track.
It works!!!!!!!!! Thanks, that did the trick. Having one pole looser made all the difference, thanks Newlumen 
Wow is it ever bright. This little light is blinding with the xpl hi.
Yes, thanks, it finally worked out in the end. As Newlumen said, one of the three poles needs to rotate freely in order to let the batteries come tight together. They should really make sure these things are done at the factory before letting them out the door. Oh well, learned something new and valuable today so it's a good thing.
Nice. Yay. 
Glad that issue was sorted out……just a bit of adjustment to the carrier, shdn’t be too difficult for flashaholics.
This light is in my to-buy list, even though i generally don’t like pocket rockets with the small mass coz of the year round hot weather here. I learnt it the hard way last time.
Question - With such pocket rockets in the snow, are they able to sustain infinite runs in turbo mode, till the batteries give up? Batteries with a wee bit of IR (eg 30Q) ought to be nicely heated up as well to counter the coldness so that they’d operate in optimum temps and not overheat, in addition to the heat supplied by the head area.
I was wondering if you guys could just bring along a few sets of batteries, all kept insulated prior to usage of course, and have a crazy lumens party all night long.
They always seem to step down, even in the cold weather. If there is no timer, they last much longer in winter than in summer, before stepping down. I should do a test when it's -30C outside and post the results.
I mean, even if the whole light is resting on snow? Or maybe even covered with snow on top, though that still wouldn’t be “infinite” coz the snow would melt and need manual top-up every now and then.
Direct contact with snow (or water even) is going to be that much more efficient than heat transfer to air.
Never tried it before, but it should last a long time. On turbo, it would still melt the snow around it real fast and then start to heat up again eventually. The only way to slow it down would be to keep shoveling snow on it as it melts lol.
You ought to try it this winter. It should melt the snow on a straight down path, still better than nothing i guess.
Good to know you got it sorted out. I placed an order for the xpl hi 3A version, which is the 4th ROT66 I ordered. I love this light and the only thing I want to see improved is increased mass for better heatsinking for longer high output usage. This thing is too light for the size and power, which really limits the potential for practical use. Maybe they can release a beefed up version later and hopefully with some copper.
There is no need to be too exact, so i shall be ignoring the efficiency lm/W numbers…….
ROT66 XP-L HI = 10000 lumens, 260g, working out to be 3846 lm/100g. The SST20 CW and high CRI shouldn’t be too far off in terms of heat:weight ratio.
Haikelite MT09R XHP70.2 = 21000 lumens, 600g. working out to be 3500 lm/100g.
Emisar D4 XP-L HI = 4300 lumens, 66.8g, working out to be 6437 lm/100g.
BLF Q8 modded = 6500 lm, 400g. working out to be 1625 lm/100g.
Mateminco MT18 /Astrolux MF01 = 12000 lm, 550g, working out to be 2181 lm/100g.
Included.