If you don’t want to move up to Li-Ion cells, there are 4xAA (NiMH) flashlights out there that can easily put out 1,000 lumen.

Alternatively, buy an 18650 flashlight that has on-board charging, if you don’t envision needing a standalone Li-Ion charger.

With that said, a basic 1-bay Li-Ion charger doesn’t cost much. I think I paid $1 for the Lii-100.