question

tex260z avatar image
tex260z asked

BMV-712 & 3 port BMS

Ok,

The story so far.

I installed a 100 Ah LiFePO4 mono block battery in the van, together with Victron BlueSolar MMPT 75/15, Victron BlueSmart Mains Charger, 2 x 195 watt panels, Latronics 1500 watt Sine-wave inverter, RCD, etc etc. Note no connection to vehicle, )not required).

Miserable failure! wouldn't run the coffee machine because the built in BMS was limited to 50 amps max output, and I needed about 55 for about 10 seconds, same with the microwave, very annoying so it had to go.

Upgrade to 4 x 200 Ah LiFePO4 prismatic cells, DG4S200A Separate Port BMS.

Also bought bought a Victron VBP 12V 65A battery Protect unit, (probably not required?) a BG-8S balancer, 12 volt 250 amp relay, (not required), and I upgraded the regulator to a SmartSolar MMPT 75/15, after the Bluetooth dongle died (still waiting for replacement).

So how does this all work? Fantastic! I even bought an induction cooktop which I can run at full whack for at least 45 minutes with no problems, runs the coffee machine and the microwave a treat.

Now for the latest sticking point and my question. As you can see from the attached photos I made up a battery box and due to the large variation in connector sizes for the various components I also made some bus-bars to screw to the ply box to make connections easier.

My current issue is this, I just purchased a Victron BMV-712 Bluetooth monitor, and I figured I would just replace the large negative bus-bar with the Victron shunt. However, upon inspection I note that negative Load side is marked for "Load and Charge", as my BMS has a separate negative charge lead there is no way to connect the solar negative to the shunt, my question (at last) is what will be the consequences of not have the charge side negative attached? I have see a suggestion previously to insert the shunt in the blue Negative BMS wire, but this still concerns me as to whether that might cause problems for the BMS, can anyone definitely confirm that it would be kosher please?

BMS
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2 Answers
Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @Tex260Z

You need to install the shunt between the battery and the blue wire to the bms, this way the shunt is always powered, and all loads / charges go thru the shunt.

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tex260z avatar image
tex260z answered ·

Thanks for that, I presume you are saying that won't interfere with the BMS.

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