Wayne are you using a oem MS plug or a (eBay) Chinese mag connector.
I notice that the cheaper version mag connectors seem cheaper..obviously. I also notice with the cheaper connectors that it will spark if I don't align the connector just rite on the surface. Which happens about everytime.
That is complicated.......
I bought a cheap 12 volt Surface charger off of Ebay. Turns out, as I suspected, that the charger would only handle the RT. The Pro overloaded it and literally smoked it. But that was fine, because I really mainly wanted the cable. So I used the cable from that and made up and adapter for my IntoCircuit battery. All was well.
For about a month.
I noticed that the wire on the cheap cable would actually get a little warm. They were using some pretty small wire gauge for the 3+ amps. Then one day the connector at the Surface end literally melted. :disappointed:
I simply ordered a MikeGyver connector to replace it, and being the cheapskate that I am, I ordered the non-OEM plug end version. It is working fine so far.
I'm not sure I understand where you are seeing arcing.