I need some help to see if there is a solution that will involve not using a generator. Are there any batteries that would be capable of operating a table top food warmer with a 400 watt heat element and 100 watt bulb? They are sold in a 220V and 240V models.
If there are, what would be the max duration the warmer could reasonably function. The idea is to make a portable vendor food cart bicycle. Most hot dog vendor bicycle carts use propane but will make food soggy. I just need a warming device for items like pizza or bread sticks, food you don't want steamed. A generator would be too loud for a small bicycle food cart. Are there any batteries or innovative ideas that could work?

If I had the resources, I would use a regenerative hub and pedal away took keep the batteries charged. If that would even work. I'm a bicycle mechanic but I don't really know much about electronics.

Thanks!