Soon your ultra will have 6volt capabilities anyway, the battery life will leave something to be desired but it will aid in chasing of that nicotine demon when you are out and about and really need the extra umph even if its only for an hour or so.
edit; Forgot to mentio n that I have been pretty satisfied with the imr14500 with lr as well it really does the trick on this thing.
Indeed, InnoVapor has 14250 LiFePO 200 mAh 3.2 Volt
batteries being built as we speak (or type?). We should have these on the site and ready to ship in 2 weeks or so. These will run the Ultra at 6V. The charger that ships with the kit will charge them, (Ultrafire WF-188).
So if anyone is on the fence about Ultra vs. UltraMax, rest assured you will be able to get your 6V fix with either device.
I also agree completely that the High Drain IMR
batteries with a Low resistance atomizer is a great combo, plenty of vapor, tons of throat hit and the benefit of the increased battery life when just running the single battery.
High Voltage attys (Joye Tech) are on order as well.
Cheers,
SH