I recently installed a dedicated shunt for my 24V Alternator/Wakespeed charging source (CAN connected to Cerbo and BMS). This is on a system with a REC BMS that provides its own battery current data (sensed by its own shunt) to the Cerbo via CAN.
Now when I'm charging with the alternator, the DC power displayed by the Cerbo and VRM is ≈2x what really is. I've looked around for settings on Cerbo, and read the documentation but I can't seem to find anything to correct the display.
Prior to installing the dedicated shunt and configuring the wakespeed to use it, DC Power was correct. My suspicion is the CERBO is adding the battery current to the wakespeed reported charging current, hence ≈2x.
I do have "has DC system" enabled because the majority of my system loads are DC. Any help would be appreciated.
I posted this over at victroncommunity but haven't gotten any bites.
ok, lets try a couple of things.
First, does your BMS and wakespeed both display the correct amperage readings, or could it be just a shunt scaling issue in the WS500?
Second, what happens when you disconnect the CANBus to your REC while charging with your WS500? Does it still read double?
Third, if you disable the "haas DC System" in the Cerbo, does it still read double?
1. Values appear correct. E.g. REC reports 142.8A while WS reports 151.6A (which is correct based on the DC Loads running).
2. Gonna hold off on trying that.
3. I'll try this and report back.
@Rick Admin
Verified that the KW to the battery is correct with "DC System Off", but the battery KW was always correct. It was the DC Power reported in the DC block that was wrong. I'm thinking this has to be a sign error on the Victron side.
Can you see of the wakespeed guys can weight in on whether the current reported by wakespeed to CAN should be negative or postive when its sourcing current? I would think it SHOULD be postive, which is what my custom CAN Logger software reports.
Hey Nathaniel,
I see you posted this to the Victron Venus github project as well. I also just reached out to Al at Wakespeed to see if he could offer any insight.
Hello. (Disclamer: Al of Wakespeed).
I am not an expert here, but I think you might (guessing here) be seeing some odd things on the main Cerbo screen, as from waht I understand the Cerbo will add up all the amps it knows about from each charging source, and then subtract that from what the battery is saying it is getting, and the results is tossed into the 'other' bucket. It might well be that throughout all this the Cerbo is dbl counting things?
Hey a question: Which set of CAN ports are you connecting the REC and the Wakespeed to on the Cerbo? The VEbms and/or the VEcan ports? Wondering...
Also want to confirm, you are seeing the WS500 do its colorshift from Green to Yellow/Orangish, right? (indicating the WS500 is locked onto the REC).
