MPPT 100/50 Instability / Erratic Behavior in Mixed Controller System

DIY
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1

My System Specs:

  • Batteries: 2 × Epoch V1 Elite 460Ah 12V LiFePO4 (920Ah total) in parallel (currently cabled to first then second in line but planning to change to independent equal cable lengths soon)
  • Solar:
    • 2 × 1200W arrays on SmartSolar MPPT 150/85 VE.Can
    • 1 × 640W array on SmartSolar MPPT 100/50 VE.Direct
  • Control:
    • Cerbo GX
    • Victron Smart Shunt 1000A (primary battery monitor)
    • DVCC enabled with SVS, STS, and SCS active
  • Inverter: WFCO WF-5220 (existing)

Communication Setup:

  • Two 150/85 MPPTs on VE.Can bus (properly daisy-chained with terminators)
  • 100/50 MPPT on VE.Direct cable directly to Cerbo GX

My problem is that the 640W array on the 100/50 controller is all over the place. The amperage going to the shunt/batteries jumps 5-6 amps and then all the way back up to 100+ amps when I introduce the 100/50 controller to the network. The other two controllers work just fine when the 100/50 is off.

Things that I have tried so far…

  • All three controllers with identical settings in various ranges (Absorption 13.65V – 13.90V tested, Float 13.45–13.50V, Fixed absorption time 60–90 minutes, Tail current from 5A to 15A)
  • I’ve confirmed that the firmware is current on all devices
  • I’ve confirmed that the full VE Network is working and all devices are shown.

Question:
Is there something I am missing in the setup? I’m guessing its just a novice mistake and everyone will be quick to let me know I’ve done it all wrong. Not a problem, I’ll appreciate any guidance critique you can offer that is constructive. I think the issue is in the software setup and hope that its not in the hardware. BTW, if I run the 100/50 controller without the two larger controllers it works just fine. So my gut tells me that the two just are not playing nice for some reason unknown to me. Thanks in advance for your help.

4

Have you set up a VE Smart Network over Bluetooth. If you have, disable this, you should either have wired or Bluetooth, running both can cause erratic behaviour.

5

Thank you pwfarnell, I just figured out what the issue was… and yes, I’m an idiot. I had the terminator in the wrong port. I had it in VE -Can Bus 2 and it needed to be in the same as the 150/85’s controller. That in conjunction with the fact that Can Bus 2 was set to 500mbps and Can Bus 1 was set to 250mbps it all makes perfect sense. The poor 100/50 was doing all it could but clearly the “universal translator” was unable to make any sense of the jibberish it was getting.