Having an issue with my MPPT 100/20 smartsolar charge controller. I don’t know if this is a bug or intentionally made by Victron. Here is the “problem”.
These 3 device above are communicating with each other via V.E. smart networking. Everything is working fine but when the charge controller is in "OFF mode - e.g. no solar = night), the charge controller seems to read the voltage from its internal voltmeter and not the voltage reported via the bluetooth V.E. smart networking.
As I have a load of approximately 15A the voltage drop is about 0.3V at the LOAD output on the charge controller compared to the voltage measured directly at the battery connectors (0.3 V voltage drop seems reasonable as there are some cables/fuses etc. in series between the battery and charge controller).
In FLOAT and ABSORPTION mode the voltage is reported via the bluetooth V.E. smart networking and everything is ok, but in OFF-MODE this voltage readout behaviour occurs.
As the charge controller’s displayed voltage differs from the actual battery voltage this causes some issues for me.
I have tried 2 different MPPT 100/20 smartsolar charge controllers with the same results.
Our products always report the voltage that is measured on their own battery terminals. The charging algorithm will however use the voltage reported by the SmartShunt or Smart Battery Sense.
The fact that the voltage seems ok in Float and Absorption is probably because the current into or out of the battery is low at that point so the voltage drop is low and it looks like it is reporting the voltage from the SmartShunt or Smart Battery Sense.
As the charge controller’s displayed voltage differs from the actual battery voltage this causes some issues for me
First of all, thank you for taking the time to answer.
When jumping between the “my devices” display and the actual device (MPPT smartsolar 100/20 in my case) the behaviour is a little peculiar.
Conditions:
Load = 14A
State = OFF (no power from solar panel=night)
The displayed voltage in the “my device” mode is 12.81V
The displayed voltage when tapping the smartsolar 120/20 device is slowly increasing to the actual voltage equal to the battery cell (I asume information is received via the V.E. smart networking and gradually the voltage is adjusted accordingly).
If I jump back to the “my device” display, shortly the displayed value drops from approx. 13.2V to 12.81V again. If I then jump back to the smartsolar 100/20 overview, the process starts all over again.
I have made a video at 8x the normal speed to see this behaviour.
The issue I mentioned is:
In Setting → Load output → “Load switch low voltage level” <12.90V in my case, therefore the output is cut off in the Smartsolar 100/20.
This is not a big deal as I now know that the smartsolar 100/20 is behaving like this, so I just lower the “Load switch low voltage level” to a lower level.
It seems that my previous answer was incorrect for most of our products. Only the OrionXS always shows the actual output voltage, all other products show what they think is the battery voltage.
And then to fully explain what is happening here, you also need to know that, to save power, the reception of VE.Smart Networking messages is disabled when the MPPT is off. But while a phone/tablet is connected, the reception is (temporarily) enabled to be able to report who is seen in the network.
So what happens here is that while you are in the main device list, VE.Smart networking is off and the MPPT has no Vsense information. So it shows the voltage that it measures on its own battery connection. But when you connect with the phone, it enables VE.Smart networking reception, it starts to receive Vsense data via VE.Smart networking and (slowly) adjusts the reported battery voltage to the actual battery voltage, instead of the voltage measured on its battery connection.
So this explains what you see happening. I can imagine that this is confusing and not always convenient. We will investigate whether this can be improved in a future firmware update or not.
Thanks for all detailed information. A power saving feature while in OFF-mode. I fully understand now!
One fix perhaps is to include a software ON/OFF-switch for this power saving feature. In my case I have plenty of battery power so saving these extra (m)Ah is no issue for me.
Thanks for a great product and hopefully looking forward to some kind of firmware update in the future regarding this.
