Question about Swaytronic Starter Light 800A

Actually, jump starting has nothing to do with the engine but with the capacity of the battery and the starting current of the starter. Of course, a starter draws more current with large engines. But the Starter-Light has a 15 Ah battery installed that can deliver 800 A for a short time. In my opinion, that should be enough for most vehicles. The battery is also not inexhaustible. If the engine does not start after 2-3 attempts, it has little to do with the jump start. Rather, it is a problem with the engine. A VW bus does not have a very large battery and the starter motor does not draw an excessive amount of current. I am sure that it is possible to start the bus with a weak battery without any problems. I drive vehicles with large and older batteries. In winter, it can happen that the battery does not provide the necessary capacity when standing still for a longer period of time. I was still able to start the vehicles with the starter light. The prerequisite is that the engine is in good working order.