openinverter forum

good work! interesting approach with clocking holes for the leaf motor to get the "perfect" angle. looks like there is ample surface area over lap for the coupler. your going to likely crack a cv cage or blow the gearbox before the coupler comes remotely close to breaking! my 4mt (and coupler) is still going strong...and i have been very very very hard on it.

nononononoonoononnnnoonononononononoonononononononoonononononononononooooooooooooooooooooo i let out some magic smoke

Looking for some advice.
Setting up the WDR Automisering BMS today and it was going great. I downloaded the BusMust CAN GUI to confirm the CAN dongle works. I figured out how to download and open the WDR GUI and it seemed awake. Then i disconnected 12V while i plugged the Ioniq CMUs into the battery modules. First the orange CMU harnesses were plugged into the front and rear of each module then each CMU was connected to the large black connector on the harness in the order of 1-2-3-4. Then i smelled the magic smoke and about 10 seconds later saw a swirl of smoke coming out of the CMU connected to 2 where the yellow arrow is. AHHHHHHH! I frantically managed to unplug all the CMUs in about 10 seconds. The other 3 were cool to the touch and the hot one is smoked as you can see. The modules all measure between 23.84-23.87V.

Possible causes I can think of:
1. My first thought was that somehow HV leaked onto the LV wiring, but i don't think that is the case because i didn't see where anything was touching that that could have happened. The only way i could see that is if the exposed shielding of the twisted and shield pairs touched a battery terminal and somehow brought that into the circuit, but the shield aren't grounded anywhere yet and i would consider this pretty unlikely.
2. I assumed that the CMUs and BMS are inactive until powered on and i press go. After connecting everything up i was going to connect 12V and open up the GUI to read cell voltages and thought there would be a command to balance the cells if i wanted to. Now I'm wondering if the balancing is passive and when i connected the CMUs the balancing process began. I wasn't planning to balance the cells so i didn't reconnect all the modules. I highlighted with red lines which modules are connected and as you can see all 4 modules in the second set are connected AND the bottom module is also connected to the top module of the 1st set. I think the CMU began balancing 3 modules at 24V with one module at 48V.
3. The large grey deutsch connectors i made that made to string the CMUs together were only loosely fitted. For some reason i didn't push the plugs into the receptacles all the way so maybe some pins were only barely touching while other pins weren't touching at all. Only CAN is going through these connectors so idk how that could have caused a failure like this.
4. The CMU harness was connected "backwards". If the module plugs closest to the CMU are connected to the negative side of the string of 4 modules and the plugs furthest from the CMU are connected to the positive side of the string, would it be problematic to connect the harness backwards? Sets 1 and 2 are connected with the CMU closest to the negative module and sets 3 and 4 are connected with the CMU closest to the positive module.

Glad i still have all my fingers, toes, and modules! I wasn't wearing my HV gloves since i wasn't planning to doing HV stuff and that is a lesson learned.

Any help is appreciated!

other lesson learned: whenever you get the feeling things are going well and you're doing great it is a surefire sign something is about to go wrong! That's happened three times in a row.

The redneckifiction of my garage (gararge as they say around here) is complete. IOW i built a plastic tent around my car workspace so i can work through the winter via space heater more comfortably. After a full day with the space heaters maxed out i got to 45F when it was 32F outside. ugh. it's going to be a long winter!

Then i had a call with Walter of WDR BMS fame and we started to get my BMS set up. It went really well except for realizing i think i killed another Hyundai Ioniq 5 battery module. When i was measuring cell voltages my probe touched two neighboring pins on a voltage sense connector. I didn't know not to do this because the cells are fused and now the module might be bricked A $200 FAFO. To reduce the timeline i'm going to get the car running with 12 modules (3 packs of 4 modules) instead of all 16. That way i don't have to source 2 more modules or build the 4th pack yet.

Then i got the first battery box built! I used a rolling pin mathod to get the thermal paste to the right height to barely touch the bottoms of the cells. I think my spacing worked out a well as i could have wanted. When i rest the module on the paste there's a .01-.03" gap between the mounting surface and the module. This gives a teeny bit of pressure on the cells, just enough to make them touch without deforming the pouches i hope. When i lift the module back up you can see a tiny bit of paste stuck to the cells and the very faintest outline of where they touched the thermal paste. I learned from the hyundai technical service manual that this paste gets installed as a 2-part mix, therefore i'm guessing it's much softer when the modules are installed at the factory than it is now. Hope i get some ok heat transfer out of this complex design i've made.

Next i started to install my motor mounts. that's going ok and the motor is now supported in the engine bay without a crane for the first time and that feels gooooooood! Gonna have to take them out for painting before final install.

Got everything installed for the first time! This is just temporary for fabricating the motor mounts and getting cable and hose lengths. Now it all has to come back out for painting the motor mounts. It's a bit of a messy look, but so psyched i got it all to fit with 1/4 of the batteries under the hood! The motor is clocked at 45 degrees which makes a lot of odd shapes for fitting everything else in. My 3D scanner lied to me a little bit and I have to mod the battery box mounts to bring it an inch lower and half an inch forward.
motor and PDM
motor, PDM, and PRA
motor, PDM, PRA, and battery box!