Get the 12V one. USB barely warms lunch.

Yes, electric lunch boxes exist, but skip the USB versions—they barely warm food. The ones worth buying plug into a car’s 12V socket.

Those 12V models are basically a small heating tray that plugs into the cigarette lighter. They pull 40–60W and heat food from fridge-cold to actually hot in 20–30 minutes. No car? A portable power station with a 12V outlet works just as well.

True USB-A (that’s the regular flat plug) only delivers about 10W. That’s not enough to heat a meal—most so-called “USB lunch boxes” are just insulated warmers at best. The exception is USB-C PD models that can pull 45W or more, and those do work. But you need a hefty power bank to feed them, and they’ll drain it fast.

One more thing: these reheat already-cooked food. Don’t expect to cook raw chicken in a lunchbox. And check reviews that mention actual temperature—you want one that gets up to around 60°C+, otherwise your food is sitting in the bacteria danger zone.

A hot lunch is a lovely thing, but only if the box actually gets hot.