I just opened up a rechargeable spotlight I own. It is "500,000 Candlepower" according to the label and has a very bright and tight halogen beam.
Inside is:
1. Battery - 6 volt 4.5 ampere hour sealed lead acid. measures 4" x 2 5/8" x 1 3/4".
2. Lamp - halogen 6 volt 55 watt.
3. Misc. - switch, charging jack, charging regulator circuit (recharges from 12 volt source).
4. aluminum reflector with glass face.
Amazing what a lead-acid battery can deliver. As a kid I built a radio control car, and powered the motor with some sealed lead acid cells taken from a rechargeable 'weedeater'. With heavy use of throttle you could keep the wheels spinning constantly, and these are large and fairly soft rubber wheels on asphalt! I think the cells were rated at 2 volt 2.5 ampere hour (the car used 3 of them). In ten minutes of heavy use you could use up the charge.