Well, Angelholm is about 120 km north from were I live, it’s a lovely place especially in summertime. Say hallo to your wife, I’m sure she knows Trelleborg.
OK, open connectors is when the “jumpers” between the cells are on top of the battery. If they are you can get hold of 2, 4, 6, 8, 10, or 12Volts on a 12Volt battery. If not a variable resistor is possible but it will have to be 500 to 1000W rating. If you are in to electronics you can build a pwm circuit with some paralleled mosfets for step less controlling of the speed. Or you can by a complete unit. It all comes down to costs, time, and interests. I’m sure there are a few more alternatives to but it is possible.
Ante :roll: