Will running this off my car flatten the battery?
It can, if you run it with the engine off for the full heating cycle. An 80-watt heater from a 12-volt socket draws roughly seven amps, and running that load for the 20 to 30 minutes TRAVELISIMO quotes with the engine off is a meaningful drain on a starter battery. A healthy battery copes fine. One that is a few years old, in cold weather, after a short journey, may not, and a vehicle that will not start is a far more expensive problem than a cold lunch. The safe habit is to heat the food while the engine is running, which is what most drivers do anyway on the approach to a break, or plug it in as you set off so it is ready when you stop. Many modern cars also cut power to accessory sockets when the ignition is off, which solves the problem automatically.
Will it blow my car's fuse?
Check your vehicle's accessory socket fuse rating before the first use, particularly in an older car. Most sockets are fused at 10 or 15 amps, which comfortably covers this device's roughly 7-amp draw, but a socket fused lower, at 5 amps, will blow. If a fuse blows repeatedly, that is a sign to stop using that socket for this device rather than to fit a bigger fuse, which risks damaging the vehicle's wiring.
Is it safe to eat food that has been warming slowly for half an hour?
Yes, if you start it right. Bacteria multiply fastest between refrigeration temperature and proper hot-holding, and the general guidance is to move food through that range quickly and limit total time spent there. Start from properly chilled food rather than a meal that has been sitting in a warm cab since seven in the morning, the clock starts when the food leaves the fridge, not when you plug the warmer in. Use a cool bag or a vehicle fridge if your day is long, and reheat food once rather than repeatedly.
How much food actually fits?
About 1.5 litres, which is a generous single meal, a substantial portion of rice or pasta with sauce, a stew, a curry, or a main with a side. It is not enough for two meals or for a large main plus separate side compartments. Before ordering, fill a container you already own to 1.5 litres and put your usual lunch in it to see whether it actually fits your habits.
Can I put it in the dishwasher?
TRAVELISIMO's listing calls the stainless steel inner container dishwasher safe, but the printed care instructions that come with the unit say hand wash only, so hand washing is the safer habit until that is cleared up. The heating base, which contains the electronics and the element, should never be washed under water; wipe it with a damp cloth instead.
Is it secure enough to use while the vehicle is moving?
Secure it so it cannot tip on a corner, a container of hot food loose in a footwell is a genuine hazard. Route the cable so it will not foul the pedals, and treat the cable and its connector gently, since they are the most stressed parts of a device carried in a vehicle over rough roads. Coil rather than kink the lead, and unplug by the connector rather than by pulling the cable.