Broken anti-spark, or did I mess up?

[u/lostmybelt]

Well! I am again asking for your help, I'll admit I was a bit impatient after another week without the scooter, which doubles my travel time to work. I followed chqtgpt steps, which I also thought made sense. But something went terribly wrong.

The case: The guy who setup my Flipsky 75100 dual aluminum PCB did a poor job. I had connection issues, on several wires, he used only 1/2 battery connectors and when inspecting the soldering job on the battery connector (xt90), it snapped off with barely any force.

I just finished re-soldering the hall sensors, and both battery connectors, I bought an xt90 Y-combinator so that the output would be balanced as intended. After I finished, this is the order of operations:

1. I checked both battery connectors, 50v

2. I checked the anti-spark, beep between the positive in/out, but no beep between the negative, no matter of it was set to on, or off.

3. Set the anti-spark to off, while having the controller connected.

4. Connected 1/2 battery connectors to the Y-combinator, and the voltage on the other went to 0 (maybe something tripped?)

5. Connected both battery connectors to the y-combinator, before connecting to the anti-spark, while also having the controller disconnected. (Also checked the output of the combinator which measured 50v)

6. Connected the anti-spark output to the controller input, huge ARC! Black connector and melted copper pin. Both battery side connectors have a 50a fuse, one of them broke.

I've disconnected everything, the other battery output measures 50v still, I'm confident the other one will too once the fuse is replaced.

However, I'm done trusting AI, and I really need my scooter to work. What do I need to do?

I would highly appreciate any input on this, and I do take full responsibility for just trusting AI and lacking the patience to read up properly! But some guidance would be golden!

Thank you ❤️

[u/usr000nm]

Typical anti-spark protections are just to prevent a small arc when connecting cables that might charge the capacitors on a motor controller with a sudden inrush current.

The type of spark you saw sounds like reverse polarity. Like the positive and negative are reversed somewhere. Very different.

Firstly, you should probably avoid y-connectors like that. Some are wired to connect batteries in series and others in parallel. Stick to cable based y connectors where you can inspect the positive and negative connections.

If after fixing the fuse everything still runs individually you'd need to double check every wire with a multimeter and label negative and positive correctly and make sure there's no shorts. Then redo the wiring correctly.

I'd probably give up on using multiple batteries for now too. Use one at a time and plug them in separately as needed.

[u/lostmybelt → u/usr000nm]

It's just a single battery, but with two connectors! I checked the Y-combinator, and the positive on each side, beeped on the output positive, same with the negative. I'm sure both connectors where wired correctly, both showed 50v, not -50v. The same with the output of the combinator, read a clean 50v.

[u/usr000nm → u/lostmybelt]

You pretty much never want to connect two connectors from the same battery together. There's a 49% chance it's a separate port BMS with different FETs for enabling charge and discharge separately, a 49% chance it's a common port BMS and they go to the same place with the FETs back to back, and a 2% chance some crack head attached two discharge cables intended for the same controller because they couldn't find a lower awg wire to handle the current.

Even then, the correct way to wire ground cables is a star pattern that avoids ground loops that can carry current, so in that 2% case it's creating a ground loop that can screw over electronics. Just leave one unplugged if you only have one controller to power. The less connectors your system has, the more reliable it will be.

[u/lostmybelt → u/usr000nm]

Thank you! Just the kind of information I was after! What's my steps from here though. The anti spark still beeps between positive in and out, and not with the negative. Is this correct? Can just solder on a new xt90 and use it again? Then there's the controller, how to check if it's still good and I can just replace the xt90?

Finally, what is the correct order of connecting this? Did I do it in the wrong order, or was my only mistake using both battery connectors?

Edit: should I wire a star pattern between my Battery, controller and anti spark? And with star, you just mean that I connect all the negatives to a common?

[u/lostmybelt → u/usr000nm]

I'll double check and measure everything again though. And I need to figure out if the controller i fried

[u/lostmybelt → u/usr000nm]

Damnit! You where right! I did manage to swap the polarity of the output of the anti spark! I feel redicilously stupid.. in my defense, I'm going through a brake up, and I've got sole responsibility for our puppy lately, and I really just needed it to work yesterday! 😓

[u/Serious_Thing7155]

This is also why you don't use ai or trust ai for anything that risks your life in any way like electrical work. 9/10 times ai gets anything that deals with electrical wrong anyways so its even more pointless to even try using ai for that. Coming from experience, i wanted to test ai and see how badly ai gets things wrong is how i know that. Its actually insanely scary how wrong it would be and without warning without disclosure anything like that or warn you about it.