Hi,
I feel like I am missing something with this question because I am not sure why you would not be able to use jumper cables. If the engine has a 12 volt battery system then you are fine jumping it with another 12 volt battery.
It is hard to say what caused a battery to drain overnight because any electrical load left on or coming on improperly will cause the battery to drain.
Here is a guide that walks through the basic and most common items:
https://www.2carpros.com/articles/car-battery-dead-overnight
If you don't find anything with these items, we will need to perform what is called a parasitic draw test. That is where you hook a meter in line between the negative cable and the negative battery post. Then when you find that you have a draw (10 milliamps or more) you start removing fuses until the draw drops to a normal level. Then you know what fuse caused it and that system is the issue. At that point it is either the component on that circuit or the wiring/switch/relay on that circuit.
Let me know what you find and we can go from there. Thanks
Tuesday, September 10th, 2019 AT 3:40 PM