I want to wire and use my REC ABMS, using a seperate charge and discharge contactor. I went for the Victron compatible version, have a Cerbo GX. But now I have trouble understanding how to do it, looking into the manual. The Victron version shows "main" contactor and "relay 1". MPPT and Inverter go through main - so that means charge and discharge are not seperate. The relay 1 is "user defined". How do I wire it? The non Victron version has the "main" labelled as the "discharge".
I also wonder if I need to reconfigure things, and whether I need the PC software or the Wifi module - and where I can get it. Can I just buy a download link or do I need to buy it with hardweare? Because the USB interface I can get somewhere else.
It would be great if you can help me because I need to get the battery up as we are livin on board. I thought it was clear but just now realized the differences in the manuals.
Thanks
In older versions you had to have a special software build for a 2 relay system but now with vesion 2.9 firmware , when you have the wifi module you can confgiure your spare relay and opto ouputs to be controlled by voltages, temperatures or even alarm events using the "Tasks" page on the WiFi module.
Keep in mind that with a Victron interface the REC Smart BMS will control your Smart Victron Inverter, charger, and MPPTs using DVCC control through your Cerbo and over CANBus, so that a 2 relay system with a split bus really isnt used that much anymore. This is far superior to a hard trip, which is only now needed in the event of a device failure, where the BMS can not control it any longer.
Here is a sample drawing link that might help: https://rec-bms-na.com/download/31/rec-active-bms-sketches/1317/rec-active-bms-wiring-diagram-rec-active-bms-2-relay-1-0-3.pdf
And here is the latest manual: https://rec-bms-na.com/download/8/rec-active-bms/1274/rec-active-bms_victron_wakespeed_compatible_v2_90.pdf
Thank you for the quick answer. That helps for understanding.
I think, having seperate relays is a plus for safety. If the CAN fails, I can still use electricity, which is important on a boat. The same applies when I have a charge cutoff, I can still for example use the autopilot etc.
Is this also configurable with the PC software? I am looking for a fast solution and hope for a download rather than ordering another module (it is also more expensive).
I have now ordered the wifi module. I had seen your links for the manual and wiring. I can configure relay 2 for UV, and then connect my load bus there. However, I wonder about the parameters: In the drawing, it says I should change RE1H and RE1U attributes. These parameters are not listed in the latest manual. Is there an extended parameter list somewhere?
@Miro
I agree with you that a seperated load and charge bus gives extra safety.
If the charging part from the multi, or any datacable fails, AND there is a cell imbalance, one the cell can reach the trip voltage. This should switch off only the chargers.
With seperate load and charge bus AND a Multi which is charger and and load, you could connect the Multi to the Charge relay.
If there is a problem with a charger side from the multi, the charge bus switch off AND also off course also the 230AC inverter from the inverter.
YOUR DC load bus stays on.
Disadvantage from this setup is that the multi has a standby power drain.
In case a low cellvoltage, the multi can drain the cells through the charge bus too low.
I would only advise this, if there is also solar system installed, too avoid a cell goes too low.
To have the multi on the load bus will work on the water also good.
Becasue the Multi is then only use as a load.
Or you must run a generator.
If you understand the above, you can make your own choice.
Ben, thank you for your input. In my setup, charge sources are solar and a DCDC charger.
The DCDC charger is fed by a non Victron AC shore power charger which I cannot configure for Lithium, and when not on shore it is fed by the alternator, which has a smart regulator but that is also not configurable for Lithium needs.
I chose the Victron DCDC also to limit the charge current.
So my plan is to wire it with the split bus, as planned.
Maybe the community can help me with another question - Right now I have no inverter on board and I am not planning to get one, if I do it would be 1000W maximum. Right now, I see no reason to install the precharge module, as there is no device which causes high inrush. Is this correct? If I add an inverter later, I would add the precharge module then. Does this make sense?
But a 1000W inverter can have an inrush current!! Maybe not high enough to damage the contacts from your contactor. All depend which contactor you use. If you have a 500amp contactor it will probably not damaged, a 100amp contactor maybe. Difficult to say. The Victron DCDC chargers are not controlled by the BMS CAN or Victron VE-bus or VE-direct, this means it is good to have them on a charge bus, OR have the Charge output switch off the charger.
I know, that when I will install the inverter I need the precharge module. I just wanted to be sure I do not need it right now. Contactors are 500A Kilovac EV200AAANA.
