Hello everyone,
I’m hoping to offer my funny epic fail story in exchange for some advice.
Last night I had my board on the floor by my desk to make some small tweaks in the VESC. Once done, I unplugged the board and set the micro-USB cable on the desk. As I got up, I bumped the cable. It fell off the desk, onto the board, and came to rest precisely on/in the charging port that I stupidly forgot to close. Two or three sparks flew and I immediately pimp slapped the cable. At this point there was a 3/4" flame coming out of the charging port. It took me about 5 seconds to set my amazement aside and smother the flame. Here is the aftermath:
At first I was assuming I would be looking at a new esc and/or battery, but after inspection, I was surprised to find no visible damage inside the esc compartment, even on the rear of the charge port. This kind of makes sense, because you wouldn’t expect a 5-second BIC-lighter size flame to transfer much heat past the metal plate into the deck compartment. The VESC is spaced from the metal plate with standoffs as well so I would think it came out unscathed, but I haven’t powered the board since the incident.
Here’s a pic of the VESC compartment near the charge port
This leads me onto my questions. Any help is immensely appreciated:
What exactly do you think happened? Did the spark originate from the powered cable or the board’s battery? (I would imagine it came from the board)
What are the potential damaged components beyond the melted charge port? Since the BMS limits charge/discharge for safety, wouldn’t it have protected the battery in this case? Could the BMS be damaged? Are there other potentially damaged components?
If you were in my shoes, how would you proceed? Should I throw a new charge port in it and test it out, or do some components need to be replaced for safety?
I’m thinking the metal of the USB head touched the barrel pin and wall, making the no no connection.
Did you have a fuse on the charge port by chance?
Unplug the charge port like in your picture and see if your board turns on. Do it outside on a stone surface away from people pets and other preciouses. Keep a fire extinguisher or bag of sand near by for bonus safety points.
If it turns on, just swap the charge port and add a fuse if you didn’t already.
Are there any signs I should look for to identify battery issues? Maybe decreased performance/range?. Is there any reason I shouldn’t test it with the charge port disconnected?
Adding a fuse on the charge port seems like a no-brainer. I’ve seen a build that uses something like these fuse holders. I’m not sure if I would need 2 fuses (one for each wire going to the port).
Thanks for the feedback guys. I’m probably going to take the board to a safe spot tomorrow and power it on for a quick test.
As for the charge port, It’s looking like 2-4 weeks for a replacement from the original company . It’s proving difficult to find a more expedient replacement (it’s a 5.5mm x 2.1mm single pin port with 2 wires leading to a male connector (2.54mm JST SYP 2 Pin).
I did find a scooter parts site with a very similar port that ships from the US reasonably quick. Not sure if this is even a match, I’d have to check with the battery manufacturer. If it is a match, it should be as simple as soldering on a fuse holder with a 7.5A 58V fuse, and I could just eliminate the connectors and solder everything. I don’t see the value of buying a connecter kit and crimp tool to redo it once there’s a fuse in place.
The sparks and fire are actually a good sign in terms of thinking “What did I break”, because it means the short had a very poor, high resistance connection which got burned through quickly. Essentially, if you saw no sparks, the connection would be way more solid and way more amps and heat would be going through the wires and cells.
Yeah I also avoid carbon enclosures now. They really can’t offer anything that fiberglass doesn’t offer more of, except appearance maybe. And they are transparent to radio and can’t short stuff out.
Carbon offers way more stability imo, they are really hard to break. Also you can just put your pack in there, no need of fixing stuff to your deck. Paint solves most of the issues around shorting, but yeah, without external antennas you get really bad reception for sure. Also they’re hella expensive, for the last carbon enclosure I made I paid 50€ in fabric alone.
you can do that with fiberglasss. I’ve been doing it for six years. mounting things to the deck is hard on the components. even evolve mounts components to the enclosure.
. It’s proving difficult to find a more expedient replacement (it’s a 5.5mm x 2.1mm single pin port with 2 wires leading to a male connector (2.54mm JST SYP 2 Pin).
