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Using the BMV 712 to switch off a relay

Can i use the BMV 712 to switch off a relay in a high voltage situation, if so how should it be wired?

Thanks

BMV Battery MonitorRelay
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5 Answers
Paul B avatar image
Paul B answered ·

The relay on the BMV 712 is a normally open relay and it closes when a alarm occurs (the relay can be reversed if required) it would be required to be reversed for you as you want the relay closed all the time so the main charge relay is activated all the time and turns off (goes open) when a high allarm occurs.


There are two relay contacts, so a connection from the battery Pos to a 2 amp fuse from the fuse to the BMV relay contact, (does not matter which one) then the other relay contact on the bmv to the main solenoid pos wire and the other neg solenoid wire to the neg of the battery.

The solenoid then will be powered until a alarm occurs

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big-ste answered ·

Many thanks, that's great.

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dazey77 answered ·

Is there a difference between the BMV-712 and 712 smart? The 712 smart has a single relay but both the normally open and normally closed poles are available.

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The only difference is that one unit has Bluetooth capabilities, and it's predecessor didn't. The relay functionality remained consistent.

the 712 also has a bi-stable relay, so it doesnt take energy during 'active' state.

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little-john answered ·

Hi Guys ,

I am new to the community and I would like to say Hi to all great people here that are so kind and help/advise other on how to get the best use of Victron products and most importantly to stay on the safe side.

In my case I seek some advise in regards on how can I use the BMV712 to protect my DYI 18650 battery pack from over/under discharge.

For solar charging I am using Victron 75/15 smart MPPT charge controller.

I am thinking to get the 2 BP100 Bluetooth version so I can program it for Li-ion chemistry and one of each for over/undervoltage disconnect.

If anybody can give some advise what is best approach in my case will be much appreciated.

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fabesgl answered ·

Hi guys. I also have a question regarding the bmv 712 relay. I recently purchased a cyrix li ct to charge my auxiliary lithium battery of my sprinter alternator. In order for this to work I was told I had to purchase a ve.bus BMS. This is what turns the relay on and off? I tried without the ve.bus BMS but had no luck getting the solenoid to activate. All voltages were in the right range to do so. Once I installed the ve.bus BMS the solenoid activated but did not de activate at the voltage I wanted it to, as I'm using Winston lithium batteries and not victron.

What I would like to do is have my bmv 712 turn off the cyrix li Ct when it reaches about 14v via the in built relay. Im thinking I can direct the pos wire that comes from the ve.bus bms, through the relay plugs on the back of the bmv 712 and then to the pos battery terminal. There are three plugs on the back of my bmv 712. com, NC, no. I have no idea what plugs to use as the manual doesn't say much on this. Im not even sure if this would even work?

Looking forward to hearing from you guys

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