BMV 700, multi plus 12/2500/70, Mastervolt whisper 6 generator, 570w solar array, TriStar mppt and 8 t105 batteries.
asked
My bmv 700 has suddenly stopped displaying amps/watts and amp hours. It still shows volts ( which fluctuate with the sun on my solar panels ) and soc. What has happened? It worked fine before.
Hi,
maybe the measurement PCB got loose or the shunt got short circuited as a guess.
Regards,
Markus
Have you made ANY wiring changes just before this happened?
Are the negative cables from ALL loads & the charger connected to the correct side of the shunt?
Do you have an earth/chassis link cable & if so is it connected to the 'battery only' side of the shunt?
Do ALL loads have a proper negative return cable/circuit running all the way back to the shunt? (NOT using the chassis as the negative connection)
As per earlier response from @Markus, the issue of NO current being measured could be caused by;
- Some kind of short across the shunt
- Loss of electrical connection (open circuit) between the PCB & the shunt terminals/ends
Other reasons could be;
- A fault with the actual PCB or the BMV display
- Loss of electrical connection (open circuit) somewhere in the UTP cable or one of it's connections
If all the basics checks out OK, maybe also try to;
- Disconnect power to the BMV & reconnect after a few minutes delay.
- Have a play with the UTP cable ends by holding it at different angles while running a load & watching the display
Hi @Mark,
nice addition. Thanks!
are you sure if one side of the PCB got completely loose somehow, the values get higher?
In my opinion, if one side got loose, the values should be zero.
Regards,
Markus
Just wondering if the cause was ever found. I have the same, but my system was working for several years and has not been touched. All seems to work fine except the display. It could be a faulty board/BMV but I'm hoping it has to do with synchronisation. My system has not been fully charged in a week and solar is a bit low with the rainy weather.
Will report back if it is sorted.
OK, while there is no reply I can update this post.
It seems it was indeed a case of synchronizing the BMV once the batteries were charged.
I don't know why it would have lost it's synchronisation but will keep an eye out.
