Negative battery terminal connection issue

[Sasquatch]

Ideally everything (bar a battery monitor) should go via the chassis on the negative side, but you delivering a jump charge straight off the battery is correct for the donor vehicle.

 

[Blackberry66]

Jumping on this thread, recently bought a Bluetti Charger 1 and can't figure where to attach it to the negative terminal either. Like you say, every instruction I've found online and from Bluetti says to attach to the negative terminal.

Can you provide an update when you've tried the headlight fixing bolt? Thanks

Yes. I fitted the negative terminal to the headlight mounting bolt. Initial fitting gave me a slightly high reading but a bit more sanding of the area got me a good connection on the multimeter. Works fine now and no flat battery. I did ask this question on a bluetti forum too, which resulted in bluetti uk contacting me directly. They said I had a very unusual vehicle. Not many VW vans like ours on the road are there