where do you found the black wire directy from the cells?What do you mean "40w"? I have such battery in my scooter. I rewired the black wire and I'm riding..
Although I hope not, but probably that's a stupid question... 🙈 l need to know how did you solder a wire to that negative output, that you pointed out in the picture?
I cannot get any cable to stay / stick soldered to it. Solder doesn't work at all, even if I try to put some solder there as a "bridge" or "foundation" it just keeps floating (away) and doesn't connect at all.
It's so Anti-Sticking, one could think it's Teflon, the materials don't connect and there is no stable connect possible although I cleaned it before with some silicon remover and alcohol, I tried solder paste on it lol and even my hottest solder iron neither makes that solder blob melt, nor do I get my solder and therefore any cable to stick to the contact. Any ideas, can you guys help me ?