We have installed a new 300Ah NG 24V house battery bank on a boat using the VE Bus BMS NG to the multiplus-II and then to a cerbo with touch gx. We have the house bank connected through a smart shunt and the aux input to the start battery. The owner has now asked to be able to monitor the generator battery so they can view it on the screen and through VRM. Should we use another smart shunt on the generator battery? My concern is if the cranking amp draw may be too large even if using the 1000A shunt. Is there a different monitor from another supplier that can be used to monitor the battery and integrate into the cerbo?
It all depends on the lock current rating of the starter motor on the generator.
Depending on the size of the Gen this can be <70A to >1100A.
Agreed.
The only two interesting information pieces needed really is battery voltage during cranking and if it gets the charged voltage.
SOC is pretty irrelevant on a start battery.
Presumably the cranking is over in seconds so the shunt won’t have time to warm up beyond its rating.
The cranking can last from typically 3 to 30 sec, the shunt has relatively low thermal mass in the fingers, this is plenty of time for it to heat up.
Yes, SOC is not important here, but we would like to see the voltage and see it on the touch 50 and see it via VRM. I was wondering if there is another device we can use that can be connected to the Cerbo without having to use another smartshunt
Deleted was looking at temp sensors