Fuel cell as emergency charger for plug-in EV? In theory, I should be able to work this out (studied chemical technology and electrical engineering long, looooong ago ), but to be honest, I'm too lazy do spend 10's of hours on the Net to get all data to do the calculating. So does anyone know if this been discussed before or if it's viable? How much range (or better energy) would a one gallon canister give you? I did obviously do some searching, but haven't found too much relevant data to make this an easy DIY job, nor enough data to do a quick&dirty calculation if it's a possibility. Edit: corrected the "PHEV" in the title to "plug-in EV"