So I have some NCR18650B unprotected coming, which according to this test Test / Review: Panasonic NCR18650B 3400mAh (Green)
do 5A current pretty well.
I know the LG 3000mah D1 also looks good.
Is there a better battery for that much current?
It’s for an L2N with a XML U3 4.5A drop in.
Is there a driver involved? If you have a 4.35V charger or are planning to buy one, the LG D1 is the best for you. Otherwise you'd be better off with the NCR18650PD. Of course thats for unprotected cells, if you want some with protection, we have to take another look at some graphs. ;)
It’s a 3 mode drop in from Vinh an CPF. High is 4.5A
I just ordered an Intellicharger I4, but that doesn’t do 4.35v
Haven’t heard of the 18650PD……
Its all just wild guessing unless you tell me if you want protected or unprotected cells. ;)
NCR18650PD is capable of high currents and still has a lot of capacity.
Unprotected is just fine for for it I think, as the protection circuit cuts voltage down a bit, and it will be apparent on this light when the battery needs charging 
Looking at HKJ’s charts, I don’t see the 18650PD beating out the 18650B unprotected at 5A current, but i might be missing something.
Might be because HKJ didnt test the bare cell. ;)
At 4.5A drive current you are looking at a forward voltage of about 3.5V. So unless you are willing to buy a 4.35V charger for roughly 20$, your best bet would be bare NCR18650PD cells or a real IMR cell.
Well it looks like the 18650B holds above 3.5V at 5A for about 12 minutes, Haven’t found any graphs for IMR’s that will last longer above 3.5v
Guess I need a 4.35v charger and an LG D1, that battery looks awesome.
Is there a good 4.35v charger?
Well, the PD will perform better when unprotected.
NightCrawl is absolutely right.
I have experience with both (unprotected)