I can’t see how that one could weld batteries - unless you can change the tips to both be on the same side it would be extremely dangerous. Furthermore, 40kg is a fair bit of force and I’m not exactly positive about the price - if folk want to pledge for it, fair enough, but I don’t think it is a good use of SLMS funds - for £600 we could get a battery spot welder and a tig - which would weld literally everything we can think of.
I’ve used a battery spot welder at lhs a few times, it was a cheapy chinese one and was alright for that purpose, would occasionally trip the breaker which was annoying. With 13kw peak for this one I think it would run into the same problems.