openinverter forum

Hi,

So I have been using 17 kw 3 phase Tesla gen3 charger for over a year and I'm very happy with it. However it has one drawback that it's modules shut down once they reach 420v. I however noticed that in my charger one of the modules is reporting ~4 volts lower DC voltage than the other two and that module keeps charging full power after the other 2 modules had shut down. I therefore think this voltage difference is due to variance in resistor values in DC voltage sense voltage divider circuit. If I could identify this voltage divider circuit I'm hoping that by changing resistor values I could get Tesla charger to charge a few volts higher. I need this because I am running 108s system and currently am only able to charge to ~3.88 v per cell. I include photos of the Tesla gen3 board.

you should look up the IC's datasheets until you find something like a DC Voltage Isolation Sensor it will likely be connected to a long string of resistors, I can see several likely candidates on that board.

This is unrelated to the question you asked (sorry I don't have an answer for you), but it looks like you removed that module board. I attempted this morning, but couldn't get mine free. I ultimately determined that it appeared it needed to be un-soldered to be removed. Is it just those 22 locations, plus the 8 small pins at the control board? I would rather splice in the OI control board by removing the Tesla control board rather than cutting the connectors and wedging an isolator into place like most seem to do with the Gen 3 chargers. Was it a huge hassle to unsolder the module board, or not a big deal? It seems like it should be fairly simple.

Update: reassembly is a nightmare. Do not recommend.

Any idea what the 2-pin "unknown component" is circled in your picture? I missed those solder joints and broke the wire. I don't think it's salvageable. I'm hoping it's an unused thermocouple? Maybe?