After the last firmware update my mppts stopped delivering any current to my batteries, even though the PV voltage was above 21v and the state was bulk. When I checked on the connect app, they were displaying a battery temp of -1°C, which is incorrect as I'm in the tropics and have no temp sensor on my BMV. I had to dig into the settings and disable the "low temperature cut off" to get them to charge again. This happened immediately after the last firmware upgrade (1.61 and 2.44).
Hi all,
Today we released a new firmware for the BMVs and SmartShunts, still in beta, that fixes exactly the issue described by many in this thread.
The issue happened very rarely, and was rather hard to find and fix, but the good news is that that is done.
For now only available via VictronConnect beta program: https://www.victronenergy.com/live/victronconnect:beta#v600beta5
Look for Bluetooth firmware v2.46, for BMV and SmartShunt.
Make sure to install that bluetooth firmware update - you’ll need to do that by hand. (Go to the BMV or SmartShunt, into the Product info page, scroll to the bottom).
For most people I recommend to just wait a few weeks, by which we’ll have made the update available via the normal app store.
So, no need to try and get a beta version installed.
This is an old story. Few people reported this in the last months.
Sometimes showing -1°C, sometimes -18°C and even down to -273°C... I had this situation two times. After a reset of the MPPT by disconnecting the Solar input and the battery the MPPT will work again.
The problem might apear again after some time, or never pop up again...
creo que es problema de red ve.smart&smartshunt
Mi configuracion
mppt 10030
ip22 (ve.smart)
smartshunt
RPI venus 2.92 /guimod v7.32
Hi @gsalgado
You say that you don't have a temp sensor connected to the BMV, but what is the setting of the AUX input on the BMV? Is that perhaps still set to Temperature?
Kind regards,
Thiemo van Engelen
I assume that you have the MPPTs in a VE.Smart networking with the BMV?
What happens when you remove the BMV from the network for 30 minutes? Does the MPPT then still show the temperature of -1?
Kind regards,
Thiemo van Engelen
It is good to hear that the negative temperature is gone and everything is working as it should be.
Kind regards,
Thiemo van Engelen
Is there anything else I can do to debug this now? If not, how can I debug it the next time a negative temp appears?
Hi @gsalgado
What you can do next time is see what happens when you remove the BMV from the Smart network for 30 minutes.
Another thing is creating service a service log after connecting to an MPPT, one service log for each MPPT and a service log after connecting to the BMV. Then attach those service logs to a new reply in this thread.
Kind regards,
Thiemo van Engelen
Hi @gsalgado
What are the firmware versions of the BMV712 (and its internal dongle)?
And did you only update the firmware MPPT (and its internal dongle) when the problem occurred or did you update the firmware of the BMV (and internal dongle)?
Kind regards,
Thiemo van Engelen
Same problem over here. Smart solar mppt and smartshunt. External temp is about 20C. 
Same problem here too. In had a false -1 degree measurement a few months ago, and last week I got false -18 degree measurements on both mppt's. Luckily I don't have much drain on my battery, but it was steadily going down when I was away from my cabin.
Just wanted to add that I have had this issue as well
Interessting to know would be, if someone had this problem (same negative temperature displayed in MPPT) more then one time...
I already had -1, -18 and -273°C. After a complete reset the MPPT worked withour any problem. The last time I had this topic is already > half year ago. So far with no problem any more.
