Arc when battery connection is made

[Hankbob]

I’m running the 3000w cyclone with the 40 amp 48-72v Sinewave Tiny Controller, and a 72v 21ah backpack battery. When I plug my battery lead into the controller lead (XT-90 connectors) I get a big arc between the two connectors it will eventually eat the connectors. Let me know if you got thoughts on how to resolve this issue.
Thanks guys!

[Delve]

Hi, I have not built a Cyclone kit yet, but I did a bunch of research on battery connection before I built my BBSHD. I would recommend changing your connections to xt90s connectors. They are fairly easy to solder if you have a good iron and a little workstation that can clamp the wire in place while you work. They have a built in spark dissipator. I ordered these:
https://www.amazon.com/dp/B074PTHZ3M..._6YK7EbAX8ADYA

[DaHose]

I am running a battery that goes to 67V max, but plan to use it at 80%. That means usually running at a top voltage of 60V, so I decided to use a solid state battery cutoff from Luna. The cutoff is rated at 60V max, but I made the mistake of charging the battery to a full 68V and wiring everything up. By the time I finished testing, the cutoff still worked great, and didn't mind feeding my 3000W Cyclone at voltages higher than its rating. I am confident it will work great as I plan to use it. If you also plan to run at the 80% voltage level, I think that the Luna cutoff might work well for you too.


I would recommend getting the control button extender cable too. The connection point for that button cable is on the input side of the cutoff, so you could end up "losing" 4 or so inches of usable length if you have to mount the controller with the input end facing away from where the button mounts.

Jose

[D.808]

hankbob something is very wrong. for it to arc, some wiring is crossed.

[Delve]

Any circuit that includes capacitors may arc when the battery is plugged in, that's why I recommended using the XT90S spark arresting connections, they have a strip of low conducting material to dissipate that initial spark

[DaHose]

I have had some conversation with another site member who has had three of those Luna cutoffs go up in flames. Sounds like they are not so good an idea for very large battery packs, but might be ok for lighter duty use. I ordered a different model of cutoff (Emcotec Safety Power Switch SPS 70V 60/120A) that is built as a dual board. Seems it's most popular with high powered RC aircraft builders, and is rated for 70V. That seems like a better choice.



Jose