We have a vehicle (van) with a 12 V system and 4 kVA Quattro. We wish to supplement the 48 V (Pylontech) battery charge, when driving the vehicle, by charging the battery from the vehicle 12 V supply.
We have tried two different 1 kW 12 V to 230 V sine wave static inverters connected to AC-IN-1 (the generator supply to the Quattro). Despite adjusting the Quattro input current limit to minimum (4 A), shortly after the inverter supply to the Quattro is enabled the 1 kW inverter is destroyed. The output H-bridge at the output of the 1 kW inverter becomes damaged shorting the high-voltage supply in the inverter.
We believe that the Quattro inverter is essentially back-driving the inverter mains output (once the relay clicks in) and the phase alignment is lost as soon as the Quattro draws current from AC-IN-1 and loads up the 1 kW inverter.
Has anyone out there had any good experiences with charging from an inverter connected to the AC-IN-1 connection to the Quattro?
A potentially safer charging option may be utilising a battery-to-battery charger to charge the 48 V battery more directly using 48 Vdc. Unfortunately, Victron does not produce a 12 V-to-48 V B2B charger so we are considering Sterling Power unit. The Sterling B2B does not have a communications bus and is unable to communicate with the CCGX or Quattro. Therefore, we will effectively be charging blindly.
Would this possibly cause a charging conflict or race conditions with the Quattro when the B2B charger is on if the BMS is unaware that there is another charge source connected?
There’s also a mention of having to set the float voltage of secondary chargers slightly higher than the primary master charger in order to provide a clear cut off and resolve charging conflicts between the Quattro and the B2B charger. It is unclear if the B2B has a means of adjustment.
