These will be my next purchase. I especially like the phone app. Battery Monitor BMV-712 (https://amsolar.com/victron/monitor-vtbmv-s?rq=victron%20moniter) and the Battery Protect 12/24V-220A (https://amsolar.com/rv-battery-accessories/relay-vtbp220?rq=battery%20protect) Anyone out there using these or another brand of battery monitor or low voltage cut off?
I've thought of this before and now will do after seeing this entertaining video at AM Solar. https://www.youtube.com/watch?v=BJyjRUErSi8
I am thinking about buying that monitor as one of my upgrades when I get the solar on. As far as a low voltage cutoff, my Zantrex sw3012 has that feature built in. The inverter draws the most power from the battery in my case and shutting it down would let the batteries recover to a non damaging state. I don't have enough 12 volt items running at night to worry about. This is dry camping info. I don't put the coach in storage without power which might make the device useful.
Compare prices at Bay Marine Supply. Alan is a Forum Member.
Victron Energy BatteryProtect 220 Amp (https://baymarinesupply.com/electrical/isolators-21/victron-battery-protect-220-amp.html)
I have 2 BMVs, a 700 and a 702. The 712 adds built in Bluetooth. The others use an add on interface. Mine are all integrated into the Victron CCGX control. These work well. High quality equipment.
Make sure you understand how the low voltage cut off switch works. It has smart time delays built in to prevent inadvertent shutoffs. One ahould hope this is never really needed but sometimes they are.
Yes craneman, probably the low voltage device is not needed by me neither. I'm just thinking, for $120, pretty good protection for my 3 8D AGMs. 2004, FMCA, Redmond, OR. after show lot sale. Fellow co worker salesman unplugged my Monaco Signature rv and plugged his in. I came back a week later to 2 wasted brand new Lifeline 4Ds and a refrigerator with $150 in moldy meat and other food. The battery monitor, I've already run the wire for when I installed the solar last year, as recommended by AM Solar.
I am a novice when it comes to most electrical work, so before writing this, I reviewed the wiring diagram Vicrton has online. My question is-When installing the BMV-700, 702, or the 712, with the intention of monitoring both the House batteries and the Starter batteries, where do you suggest mounting the Shunt? If I understand the wiring diagram correctly, a large negative cable would need to be routed to the shunt from each set of batteries? Thank you in advance
wiring diagram https://www.victronenergy.com/upload/documents/Quickinstallsheet_BMV70x_part1_2.pdf
The shunt is located between the negative side of the batteries and the connection to the rest of the ground side of things. The shunt is measuring a very small voltage drop across a known resitance to get the current flow across the shunt. So it needs to go between the batteries and the rest of the negative connections.
Think of all of your batteries connected together as a set. They act as one bigger battery.
If your house batteries and start batteries have the ground posts connected from one to the next and then on to a longer ground cable then the simple thing to do is get a short ground cable, 3/0 or 4/0 size, connect that to the last battery post on one end then the shunt and then the original ground cable.
If you have a common bus bar the shunt needs to go between the bus bar and the negative cable.
The two photos show the shunt at the house batteries. The second one shows the shunt after the common negative bus bar and then out to the negative cable. The batteries and negative cables to the bus bar have not been installed in this photo. The third shows the two BMVs installed along with the Victron color control and two line voltage meters.
Roger, Thank you for that explanation and for the pictures. I have a much better understanding now
Thanks. Let me know if you need some additional help.