So the 5 week trip we took in Jan-Feb was mostly off-grid and without any problem with the batteries or Onan 5500 to charge. We were out about 2.5 days and noticed the recliners were not working. Looked up and noticed the microwave was dark, so hit the cerbo touch screen and the inverter was off and in error “Low Voltage”. (Stared SOC of 35%) Walked into the bathroom, fired up the Onan and all was well. Turned on the Phoneix 50/12 via the touch screen, and between the Multiplex II 3K/120 and the Phoenix we were back to 100% in 2.5 hrs.
The 36Max1 runs off 12V (stereo, internet, Starlink, Refrigerator, pretty much everything except the TV, Microwave, Induction stovetop and the electric blanket) 2 Vatrer 460 batteries in parallel so 920AH.
Bluetooth is how you see the battery SOC directly and since the 460’s are in steel cases, you have to be out in the cold or rain under the front 5th wheel overhang to bluetooth view. That has to change.
I started the quest to “adjust” the Victron Lynx shunt values to get the BMS and the shunt in sync. Long story short, after a few weeks I just gave up and ran the Onan 1.5 hrs a day and calculated the shunt SOC was pretty much always 10% too high. This is PROBABLY because I was running the Phoneix off the inverter side of the AC instead of before the Multiplus.Round Robin issue, but have not delved into why or if that is the real reason. It just is.
I noticed the JBD app connects to the BMS, so the obvious thing is to get the “hopefully” JBD BMS can talk directly to the Victron Cerbo. Well it had been done, just takes some work.
I ordered a couple of Overkill BMS to USB boards from overkill
https://overkillsolar.com/product/usb-module-for-bms/
I followed the instructions in the Video by Off-Grid Garage out of Australia.
https://youtu.be/sHIlP2oJ3DU?si=TbyJvMFzCY3F-Xdh
Yeah a bit long but he really explains the idiosyncrasies of the JBD. and an easy hack to the Cerbo (which as far as I can tell, is just a Rasberry Pi in reality, to add the JBD driver.
Now the cable that comes with the Overkill does NOT fit the JBD, (I just spliced to test)
and found it is a HY2.0 2.0mm HY-4P connector. Then found by chance the proper cable.
https://www.amazon.com/dp/B0D4PFPSMY?ref=fed_asin_title
Drilled a hole in the front removable metal panel, added a grommet, and all is well.
Plugged the USB into the USB port of the cerbo and presto see an new battery device and serial battery LTT/JBD. Configured the cerbo to use the battery SOC as the display and we are off to the races. I did test MANY times and using the LYNX with the exact same cables in parallel, the BMS differences between the 2 was never off more than 1% that 5 weeks.
NOTE: HAD to remove the Bluetooth card glued to the bottom of the case and plug the serial to USB device in the UART plug
Linear Mode
