Who needs a set of 8 matching button top cells to power that beast?
the manufacturer of keeppower cells does the OEM job for us and adds the button tops to 4000 Samsung 35E cells:
(not the cheapest option - but we decided to go quality first on those sets)
UPDATE:
It seems we can offer the cells just beside the GT without confusing codes or such :)
please be fair and DO NOT add them if you have not entered your mail in the list (which is mainly used to feel the demand)
Jump on the list when you want to pay 40 USD for a set of 8 cells, shipped nearly worldwide
While this may not be my business I believe that, since the GT uses a buck driver with 4S input feeding a 4S emitter, it may benefit from higher voltage cells like the Samsung ICR18650-30B or ICR18650-32A. I am pretty sure similar or even better runtime at least until out of regulation condition would be attained with these high voltage cells. It's terrible to see how did they choose such setup, the emitter driving voltage range overlaps with the cell dicharge range window and the driver isn't buck/boost. It's a shameful shoddy path they took just because the big cell pack plus powerful FET @#$% would have blown out the emitter.
I had the same thoughts as you. A sepic (buck/boost) regulator would have been the better choice, but also increased cost, complexity… and I suspect, introduced a myriad of unforeseen problems for the manufacturer. The limitations of maintaining regulation with the GT buck driver has also been discussed in the GT thread. You are correct, that the best performance of the GT will be realized while using cells that can maintain the highest voltage throughout the discharge curve. Keep in mind, that the discharge amps while using 8 cells in the GT will be about 1.5A per cell at max power. With that in mid, the Samsung 35E does a good job maintaining a high voltage while carrying a 1.5A load, especially for a 4.2V cell. Considering the availability of 4.30V and 4.35V cells, I was skeptical until I compared them against dozens of other cells using HKJ’s discharge comparator. Unless I missed something, the Samsung 35E is the better choice (and does not require a special charger to recharge them to max capacity).
Also keep in mind that our eyes perceive light logarithmically, and probably wont be able to detect lumen variations in the field while using any of the top quality cells that most of us already use.
