Best battery for carbon arc lamp?

I've recently built a mini carbon arc lamp and small driver circuit for my bike. (I know about LEDs, its a "for fun" project)
It draws around 1.6 -1.7 amps at 6 volts. Any ideas on which type of battery to use?
Thanks in advance -Ray

Depends upon how long you want the lamp to stay lit and do you want it rechargeable.

I'd suggest you look at battery packs for RC cars and planes, they are readily available and have high-discharge rated cells.

eg.

You will also need a matching or universal "balance charger" as packs like that do not have internal balance circuitry.
Something similar to this: