That was a close call!

Just nearly blew my board/ house up…

I just went to put the cap on my charging port, so far so good… then my wife asked about something and I turned to talk whilst still trying to put the cap on… this is when the metal side of the the cap went far enough into the port to strike an arc off the pins, which because the port faces upwards, melted the pins into a puddle in the bottom so that the arc could keep going! The plasma flame lasted about three seconds and was 3-4” tall… then by some miracle it stopped.

So, definitely should have put a fuse in the charge side of the battery!!

Everything seems undamaged with the exception of the charge port… I’ll test charge tomorrow to see if the bms survived.


Holy shit Dave. Scary stuff. Worth checking the group voltages no?

1 Like

Ouch… Good thing nothing worse happened!! Liions or lipos inside?

1 Like

Yikes. Which type of connector is that? And which type of BMS

Samsung 30q 18650’s…

The pack seems fine but I’ll give it a thorough once over before charging!

It’s a gx16 3 pin.m and a bestech.


Do you have some pictures of the port before it was damaged?

Glad that nothing went wrong Make sure to replace the entire charge port unit before testing it again :slight_smile:


There’s some images on my build thread, Here it is now…

image image

1 Like

wait, your cap is made out of metal? i dont get it. anyway lucky nothing worse happened


That’s how they come… it’ll be covered in Sugru from now on.

1 Like

The problem really stems from the fact that the charger is female meaning the male dangerous part ends up on the battery. A 10A fuse is the fix, plus the sugru.


Fuse on the board port side right? I’m looking do something about Sparks when connectting the charger.

Can someone inform on how to put a fuse to protect it? And maybe which fuse? Genuinely not sure, so an idiot guide style would be great, or a link

pic of the aftermath?

There really is not much to see… the pins in the connector are gone and there is a solidified brass puddle in the bottom of the connector… I really cannot believe it stopped arcing!!

1 Like

@Andy87’s experience made me start putting fuses on my charge port and this just doubles me down.

Everyone, can we please order these 7.5A 58V fuses and put them on your charge ports? I think every new build should have this. And those of us that have extra could toss a few in the free stuff thread.


You told me that a while back Best thing ever, fuse are life saver ! Now I systematically fuse charge and discharge

1 Like

Man I’m glad nothing bad happened!

These pins aren’t suited for e-bikes or e-boards BTW. We put too much power through these!

Edit : Had to move out before finishing my post ; anyway its good you’re safe!

1 Like

About a month ago I made a mistake while creating a cable to connect the switch to the battery and and I switched polarities. I burned an ESC and I was luck that nothing else worse happened. The switch melted and that stopped the current flow.

I don’t know why I didn’t verify the connections and correct polarity, I always have been careful about this but not this time. Now I’m on the market for a new switch, ESC and battery since it was alrady in bad condition. For now I will push a regular longboard. :slight_smile:

Probably obvious but just in case… Put the fuse on the board side, not the charger. You want to break the circuit inside the board in case pins fuse shut on the board and all hell brakes loose. Really glad you’re ok @amazingdave!