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john-collier avatar image
john-collier asked

BMV-700 not showing me anything correctly

My bmv has been showing me a voltage of -0.01 with 0 amps and doesn’t show when I’m getting solar power. I plug the Bluetooth into my Victron mppt controller and it shows the correct amps coming from the sun and correct volts.

I’m looking for a way to maybe reset my bmv in hopes that will fix it but maybe there’s another solution out there.

I’ve had this bmv for a year and a half no issues btw.

BMV Battery Monitor
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Alexandra avatar image Alexandra ♦ commented ·

Have you checked the fuse? Another possibility is that the data connections is not making good contact.

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4 Answers
Jaco Reinecke avatar image
Jaco Reinecke answered ·

Hi,

A BMV needs regular tuning, like Zeroing it again, synchronizing it when the batts are 100% etc. Just check the manual on how to set both.

Also found this video quite informative:

https://www.youtube.com/watch?v=4ReljfO3k6M

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mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi, sorry to correct, but regular tuning is not how I would describe it.


what the BMV needs is to regularly (automatically!) synchronise. Without regular synchronisations, the BMV SOC parameter will drift.


The video linked by Jaco explains how to (one time) set up those parameters & how the synchronisation mechanism works.

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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ commented ·

Further more, this issue doesnt sound like a synchronisation problem.


@John Collier please check your mppt wiring: its battery negative connection must be connected to the load side of the shunt. Not directly to the battery negative. Same for all other chargers & loads: all must be connected to the load side of the shunt.

Only one connection is to be made on the negative terminal of the battery itself, which is the wire to the other side of the shunt.

Anything that bypasses the shunt by being connected directly to the battery negative terminal will not be measured by the BMV.

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katulo avatar image
katulo answered ·

Hi all, I have the same issue, my MPPT says that is charging perfectly but monitor only shows the negative part of the energy, I mean consumption. If I turn off all devices and see in BMV 700 zero amperes, I don't see the incoming energy from the solar panels. I attached some pictures.

In the beginning I thought my MPPT or batteries were failing, but after arriving to zero charge in BMV 700 (3 days ago) and still having energy, I figured out that the MPPT 100/30 is correctly charging the batteries, but I don't have trustable information to manage my energy on board.


Regards

screenshot-2022-08-10-at-105923.png

screenshot-2022-08-10-at-105915.png, Enrique


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klim8skeptic avatar image klim8skeptic ♦ commented ·
Sounds like the mppt's battery negative has been wired directly to the battery.

Must be wired to the system side of the shunt.

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katulo avatar image
katulo answered ·

Solved here:

https://community.victronenergy.com/questions/95336/bmv-700-and-solar.html



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