I find this all very interesting. However you seem to be talking about protecting the vehicle with the flat bettery. How is the slave vehicle affected, should both vehicles have lights heater and wipers on.
bighands:
I find this all very interesting. However you seem to be talking about protecting the vehicle with the flat bettery. How is the slave vehicle affected, should both vehicles have lights heater and wipers on.
Not necessary as the donor vehicle will be fully charged and the alternator will be in freefall. I would connect the leads to the patient using my methods, then start the engine of the donor, go for a mug of tea and come back and start the patient.
I prefer to connect first the slave vehicle both clamps, than the positive clamp to the battery of the flat vehicle.
I don’t like to connect the negative clamp to the battery for reason of sparking. (don’t like any sparking near batteries, if you ever seen a battery explode you know why) but connect it to a place on the chassis (fifth wheel bolds) NEVER CONNECT IT TO A WHEELNUT!!
The current can weld or damage the wheel bearings.
If you leave the vehicles connected for a 10 minutes after you started, you avoid the spike because the alternator get fooled in that the batteries are charged.
Before you disconnect the slave vehicle pull as much current as possible with lights, heating and whatever is possible, but be carefull with your inverters.