How many amps is it calibrating at?
Opposite of what you want to do, the thin air gap between the pieces of metal is a large part of what creates the resistance to enable the weld. You want to have them firmly in place so they don’t slip, but you don’t want to be smashing them into the can causing dents like that when the weld action takes place.
Did you try the positive side?
Sure enough! Guess my guns were too much for it, can’t believe less is more in this case. Pushing significantly lighter showed significantly better results! I’ve set the min amperage to 850 if that’s what you are talking about, during calibration it shows 1490A. Picture is from 50J.
Great number!
iirc this is the standard recommendation for .2, personally I weld at 54J.
Yessir! Gotta have resistance to spot weld!
Alright this is what I get with 54J. Seemed to have made the kwelder angry with the first one due to holding it too loose I believe. Would this type of weld be what I’m looking for for the rest of the battery? I’ll interpret a like as a resounding yes in which case I’ll return once I’ve finished the first parallel/series connection.
Yeah, if the connection is not good it will beep at you loudly, have to walk a bit of a line with the firmness.
Yes, you want to see the weld holding and the nickel breaking/tearing away. with .2 there’s less wolverine like tearing action, but you’ll still see residual on the cell like that which is good.
Here is how I’ve connected the batteries thus far. Not as pretty as I was hoping, but they are rather stiff (still a bit of flex which is unavoidable?). I’m hoping plastic supports + wrap will mitigate this.
Here be my first parallel/series connection. Personally I feel like it’s pretty good but would love to get some confirmation before going to the point of no return.
Hello again, not a battery expert here so pinch of salt and maybe I’ll be corrected. I can’t see much glue inside the P groups, most of it looks like it’s between the groups outside of the fish paper. Do you have any pictures of the groups and how they’re held together? If a group isn’t rigid between the tabs it can stress the welds, so to non-expert eye it looks a bit sketch. Overall neatness and insulation and everything looks good though
I can’t tell for sure, but the location of the highlighted weld could be an issue. The center 3mm of the negative terminal is where the can is welded to the internal electrode, so welding on top of that can be a safety risk. Avoid the middle of the negative terminal
Tried to take a representative pic, glue on the inside between the cells, glue on the outside of the cells (inside the fish paper). I did my best to follow before mentioned video.
Ah! Had no idea that was something to avoid, I’ll keep that in mind for the rest of the welds!
Grand, I think you’ll get more useful feedback posting in the battery builders thread (and there’s lots and lots of old advice, best practices, and questions if you have time to go through it)
I was unsure if this warranted a new topic or if I should blend it here.
Is my VESC doomed (Makerx DV6)?
To make a long story short, not enough insulation and I managed to short the positive side of the battery with 5V on the VESC (Makerx DV6) ppm port (via the flipsky VX1 receiver). I’ve already ordered replacements, but would obviously prefer to cancel those orders if a repair not above medium difficulty is possible. There’s continuity between 5V and G on the VESC, when plugging it in only one side lights up (the one not in the photos). For the record everything was working beautifully before this incident, motors, receiver and all, but thank god it happened in the lab and not on the road. Nothing seems to be burnt or broken when looking at it under a microscope.
Troubleshotting tips and potential repair action much appreciated!
PS I’ve seen some older posts with similar problems, but had a hard time finding ones that concern this VESC and specific shorting scenario.
Well, the 5V in VESC 6/4 based designs are provided by the DRV, but a bunch of other components are connected to that rail. Worst case scenario, you fried it…but it might have survived and your short is coming from:
I would try to remove those components in order and check if the short goes away. A simpler test would be to plug the VESC in and touch (carefully!) the regulator, CAN transciever and DRV (check the MCU too for good measure). If any of those are hot to the touch (they can get VERY toasty, be careful)…that’s your culprit.
Dear, I might have to save this repair adventure for when I’m a little more experienced. Even if I manage to find the source I don’t think I could switch the chip (yet). One of the sides is still working, would it be safe to run the VESC with only one motor connected to the working side? Is there a way to “switch off” the broken one?
I think I found the culprit, and answered my own question at the same time. What would that component be called?
Yeah, running the full battery voltage on a VESC in an unknown status is not something I would recommend, because there’s no easy way to completely disconnect the faulty one on these units…
That component is an inductor, but it is very unlikely it’s the culprit. Unfortunately, it is connected to the DRV on one side and to 5V on the other. If GND and 5V are shorted, it looks like those DRV pins (PH or the output for the internal buck converter) are also shorted and the thing is toast…
As you can see in the schematic for the VESC 6:
Can you repeat the measurement from the other side of the PCB? The regulator is there, but my money is on the DRV =/
