You dont need a charge controller. They're more of a safety and battery longevity feature.
If you just need to get enough juice into this thing to outrun the next horde of zombies, any dc voltage source a couple of volts jigher than the nominal charge of the battery can do in a pinch. Cracking the pack open and charging individual cells is also an option if you can't find one with a high enough voltage.
I absolutely dont recommend this under normal circumstances, but electrics are far easier to repair from scrap than combustion engines.
Please AMD, revive ZLUDA so i can free myself from the nightmare that is Nvidia.
I would love nothing more, but unfortunately we've worked ourselves into a corner where the only way to ditch them at this point would be to re-engineer all of the external cuda-dependent code in house.