Battery Connector Arcing

[Direkt1218]

Purchased a very well used eDrift scooter from FB marketplace. I think I got a great deal BUT the battery arcs when I connect in to the controller.
Let me back up a little. The gentleman I bought it from did not know anything about it. He said the battery pack was fried. So that is where I started. No voltage at the connector Well it’s already broken let’s dig deeper. Take the shrink off and test right at the BMS terminals. Hey look 63v!!! Pack IS good just the wiring was a total mess. Finished unwrapping it and removing all the messed up wiring. Installed fresh 12GA silicone wire and xt60 connectors. Then cleaned up the wiring on the scooter itself. But when I connect the xt60 connectors together I can hear/ see a pretty good arc. So the male xt goes to a terminal strip so the pack can feed a buck converter (12vdc out) and the controller. SPD-602000BLDC controller. Nothing fancy. Am I missing something between the battery and the controller? A relay? A key switch? This arcing can’t be good or sustainable. It’s going to destroy the xt60 connectors eventually. The motor spins when the battery is connected and the throttle is applied so my rewire seems successful. At least to me it seems successful. Any guidance would be very wonderful. Thanks!

 

[E-HP]

Normal. Switch to XT90 anti spark connectors. They allow the inrush current to disipate before making the full connection.

 

[Direkt1218]

Just that simple? Nice!

 

[E-HP]

Just that simple? Nice!

Yup. Just note that when connecting them, you first make a partial connection for a couple seconds, which allows the internal resistor to take the inrush current, before you fully plugging them together.

 

[ManicMods]

Never heard of the anti-sparks, thank you! I use main-line switches for some builds which also resolves. Anything to keep the main battery connectors clean and build a little safer

 

[amberwolf]

Another alternative is to use whatever switch the BMS has built in to turn it off until after it's connected. Then no current flows and you get no arc.

Many BMS have some form of temperature sensor or power switch input--almost all of these will not allow the BMS to enable the output if that circuit is open, so adding any kind of small signal toggle switch or latching button to open it when desired will allow this function to do what you want. Some of these don't have any wires installed from the pads for it, but instead just jumper across the pads to permanently turn it on. Removing the jumper and adding a switch adds the funciton.