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dylon290 avatar image
dylon290 asked

Victron BMV-712 incorrect voltage and temp

I have 3 12V 200ah batteries in parallel. I also have victron MPPT charge controller. The charge controller shows roughy the right voltage 13,5-14V, but the battery monitor show .04V. I have tried so many things to fix. I even upgraded to the temp sensor cord, but that didn't help and the temp shows -1C even when the settings say to do F and the temp is way off. I had the cord on the same positive that the shunt was getting negative from, so I moved to the furthest battery thinking that maybe had something to do with it but no. All connections are tight, checked multiple times now. The voltage did show up correctly at one point, I don't know what's changed to make it wrong. I also have tried to reset the device multiple times. Please help!

BMV Battery Monitor
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3 Answers
Mark avatar image
Mark answered ·

Refer to the related wiring configuration in the quick install guide and make any required changes;

https://www.victronenergy.com/upload/documents/Quickinstallsheet_BMV70x_part1_2.pdf

Also check that the fuse in the BMV positive cable (connected to B1 terminal on the shunt PCB) is installed and intact/not blown, it may need to be replaced with a 1A fuse. Some were shipped with a 0.1A fuse and that was causing an issue.

Also try replacing the RJ12 cable that connects the shunt board to the BMV screen.

If your still having trouble you can post some photos of your setup/wiring or consult a Victron dealer/installer.


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dylon290 avatar image dylon290 commented ·

Well I definitely have it wired correctly, I will double check the fuse and try replacing the RJ12, but it worked fine before, so I don't know why it wouldn't work now.

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dylon290 avatar image dylon290 dylon290 commented ·

Replaced the fuse, no luck. Same .04 V and -1°C temp. I haven't been able to replace RJ12 Cord yet, as no one in town carries the right cord. Have to order online and replace later next week.

However, since I had a moment, I thought I would send some pics of the setup and screen shots results.

I will upload more soon if you need something else and let you know how the cord change goes.


BMV712


Solar MPPT Controller


Batteries in parallel, with temp sensor. Red goes up to bus bar, black at far end goes to shunt then to separate bus bard. All electrical works fine, just BMV doesn't ready correct voltage or temp. Amp draw seems accurate though.


Shunt. It's hard to take a picture in its location without moving a lot of stuff, so hopefully this works. Negative off battery is blue, white is going to my negative bus bar.



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klim8skeptic avatar image klim8skeptic ♦ dylon290 commented ·

Could transposed wires (temp/+) at the shunt cause this problem?

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dylon290 avatar image dylon290 klim8skeptic ♦ commented ·

Not sure, but the wires are in the correct location according to wiring diagram. (+ In B1, temp B2). It's also worth noting that I had the .04V problem with the old, non temp sensor cable. I upgraded hoping that would solve the issue.

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Mark avatar image Mark ♦♦ dylon290 commented ·

Im thinking that if the unit is actually powering up then it would be receiving a lot more than 0.4v. So it's most probably communication related or some other kind of fault. I would give the new UTP cable a go and if it's still not working properly then speak to your dealer.

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dylon290 avatar image dylon290 Mark ♦♦ commented ·

So, if I just got this on Amazon how to I resolve this issue? Do I just go to nearest dealer. I was unaware that I wouldn't really recieve proper customer support from Victron.

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Mark avatar image Mark ♦♦ dylon290 commented ·

I would recommend to contact the original seller for support, even if purchased through Amazon.

You can also complete this support request form to get in touch with the original dealer while also keeping Victron in the loop...

https://professional.victronenergy.com/support/

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dylon290 avatar image dylon290 Mark ♦♦ commented ·

So I bought this cable and tried plugging it in, but it's not.working. The cable is supposed to be a standard RJ12 cable, right?


Cmple - Telephone Extension Cord Cable, 6 Conductor Wire with RJ12 6P6C Plug Cable for Landline Telephone - 7 Feet, Gray https://www.amazon.com/dp/B00404JW5G/ref=cm_sw_r_cp_apa_i_lAHkDbQZAMCSM


So now, I've spent money on new fuse, not the problem, multiple RJ12 Cables that dont work and still showing .04V.



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Mark avatar image Mark ♦♦ dylon290 commented ·

Sorry to hear that your still having issues.

The communication cable provided with the BMV is a UTP (unshielded twisted pair) cable with RJ12 plugs (6P6C) on the ends. It's not just a regular flat telephone cable, although I don't know how much difference that makes. I have always used the cable provided and crimped on a new RJ12 plug myself (not easy) if I ever needed to shorten it.

Damaged UTP cables have caused some BMV communication issues in the past - you will find this in some previous posts.

At this stage your best to speak to your dealer/reseller.

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dylon290 avatar image
dylon290 answered ·

Can we mark this as not accepted? Problem not solved.

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marsel avatar image
marsel answered ·

All my Victron BMV-712 shows permanently -2.86Ampere usage. I checked all configuration and Cable nothing found out. Measurement at 410A Powerqueen Batteries shows 0 Volt/0.2 Ampere only.
Issue Fixed: First fuly charged Batterie

Power down full Victron enviroment and restartet
check for new software update

SOC syncronised to 100% and Zero "NullKalibrierung"

now it shows 0.00 Ampere

bmv-712-fix-incorrect-current.jpgbmv-712-soc-fix-05925.jpg



bmv-712-fix-incorrect-current.jpg (329.5 KiB)
bmv-712-soc-fix-05925.jpg (339.1 KiB)
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