I need a clear wiring diagram for installation of a BMV-712 (Smart) to a 24v PV system that's using 2- 12v LiFePo batteries in series (Battle Born).
The instructions, while good, aren't clear enough and have me concerned I'll wreck something.
asked
Wiring BMV-712 for 24v system?
It is the same as with one 12V battery.
You have one positive (24V) and one negative (0V).
The shunt have to be connected to the negative before it goes to the system.
Maybe you are overthinking it.
Assume you have the shunt with it.
0V negative of battery goes to the battery side of the shunt.
Load side of shunt goes to common negative for all loads and should be grounded. Also negative of charger.
24V positive of battery goes to fuses etc. Also charger positive.
There are two fused thin red wires . One goes to +24V of the batteries and from there to the left green connector(battery side). The other goes to the +12V midpoint of the batteries if you want mid point monitoring, or to an aux/starter battery and goes in the right green connector.
Then there's a plug in cable to plug into the shunt and the back of the 712.
That's it.
If you want to connect to a GX device such as the CCGX, you need to buy a VE Direct cable, this plugs into the back of the 712 and the GX device. Otherwise the VE direct socket is left unconnected.
Where does the negative output from the Victron MPPT SCC get connected to? Directly to the negative on the battery or on the negative BATTERY terminal on the BMV or the negative LOAD side of the BMV?
Thank you
Except the battery, everything is connected to the "load" side of the shunt.
But you should use busbars. Don't stack multiple wire lugs on a single bolt. Maybe two wire lugs on a bolt, if you must, but not more than two.
Is it correct to say that all negative connections from ALL components (inverter, MPPT negative battery connection) EXCEPT the battery negative are connected to the negative LOAD side of the BMV?
Is it correct to say that ONLY the battery negative is connected to the BMV battery side of the shunt?
Thank you
Yes. Any negative direct to battery bypasses the shunt/BMV and your readings are wrong.
