Are they LiFePO4 cells? If so, I believe their nominal voltage is 3.2, which puts you at 9.6 volts nominal. That's tough, as the voltage is too high to overdrive a 6 volt bulb, and you'd be driving the 1185 at spec. You might be able to run a 7.2 volt bulb off of them, but that is still a 33% overdrive, which is likely pushing things. If you still have the stock bulb tower, I imagine you could run a 6 cell mag krypton bulb off of them. A 6 cell xenon may survive as well. The other thing is to try to find a 6 volt bulb with a long (2000) hour predicted life span; it would likely be able to survive pretty significant overdrive. Sorry I couldn't be more helpful; hopefully someone who knows more bulbs than I do will chime in!