Had a run out last night we used both lamps side by side, at the same distance, the same spot. There is no difference in brightness from using a bigger battery. We only got three last night but were out or hours and the lamps were well-tested again with no problems with the wiring on the 10 amp battery. I think I'll be sticking to my lamp with the battery in the handle as it seems to have more than enough life for any night out.