I am in the process of installing MultiPlus II (48V).
I have 4x 12V AGM 150mAh batteries, connected in series to get 48V. I have connected VE.Bus Smart dongle to it and it reports 50.66V. So far, so good.
I have connected battery cables to the MultiPlus (correctly) and positive only on batteries (there is fuse on positive). No AC connected on MultiPlus.
Now, I have tied to connect negative but I get sparks! And I do not dare to do a full connect. Is this due to the high current at connection time (capacitors?) or do I have something wired wrong. I cannot imagine what I have done wrong.