Re: The V54 Lounge.
Single 18650 for most p60 modules including triples & quads the MTG2 require 2 cells because the emitter has a VF of ~6volts.
I have a regular dedomed M2500 (not F) which is great on the bars or helmet besides needing two cells to run.
I hate those two fish things.
The soft rubber makes the light flop around & slips on drops & jumps.
I recycled the straps from one and made a mount from a piece of wood hhaha
Now I'm using a cheapie solid plastic bar mount I found on eBay for a couple bux.
Runtime on high is bad for any single cell light just divide the Mah by the current draw of the light & u will have rough idea.
Ie 3000mah cell driving a 3amp driver/light will give u about an hr - tho it will be a bit less depending on low voltage cut off of the cell or driver.
Output of a triple dedomed XPL on max would probably be ~2500 OTF if driven hard enough.
Heat would get bad after 5 mins or so unless it's cold out!
I've never had a light/module die from heat yet & mine get run off of my 4x18650 parallel pack in my p60 helmet host.
The trick is to use low & med most of the time & save max for tech sections or downhills.
Out here it's kind of bad etiquette to be blasting everyone on the flats or ups with 5000lumens. Especially if it's near houses etc.
For long runtimes on high a multi cell set up becomes necessary for sure tho.