SmartSolar MPPT 100/30 does not use External Battery Current Sensing, while MPPT 75/15 does

DIY
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Title

SmartSolar MPPT 100/30 does not use External Battery Current Sensing, while MPPT 75/15 does (same VE.Smart Network)

Message

Hello,

I have a boat with the following Victron system:

SmartSolar MPPT 100/30 (Firmware v1.74)
SmartSolar MPPT 75/15 (Firmware v1.74)
SmartShunt IP65 500A/50mV (Firmware v4.19)
Smart Battery Sense (Firmware v1.15)

All devices are connected to the same VE.Smart Network.

Both MPPTs correctly use:

Battery voltage from the SmartShunt
Battery temperature from the Smart Battery Sense
Synchronized charging

However, I noticed one important difference.

On the MPPT 75/15, the VE.Smart Networking page shows:

External battery current sensing is being used from the SmartShunt.

But on the MPPT 100/30, this line is completely missing.

Both devices are on firmware v1.74 and both are members of the same VE.Smart Network.

My questions are:

Is this expected behaviour?
Does the MPPT 100/30 actually use the SmartShunt battery current, but simply does not display it?
Or is this a firmware bug or configuration problem?

I have already tried removing the MPPT 100/30 from the VE.Smart Network and adding it again, but nothing changed.

Another reason why I am asking is that I have observed an unusual charging behaviour.

After an overnight battery discharge, both MPPTs enter Float normally, but the SmartShunt still reports approximately 6–8 Ah consumed. Only later during the Float stage does the consumed Ah gradually return to zero.

I am wondering whether the missing external battery current sensing on the MPPT 100/30 could be related to this behaviour.

Has anyone experienced the same issue?

Thank you.

Note : I checked another boat which has the same MPPT 100/30 and SmartShunt.

MPPT does not have the line “External battery current sensing is being used from the SmartShunt” either!

100-30
100-301170×2532 369 KB

75-15
75-151170×2532 394 KB

2

Hi,

In a VE.Smart network, only 1 MPPT is the charge master and only the charge master is using the external battery current sensing. When you remove the PV from the MPPT 75/15, you should see that the MPPT 100/30 starts to use the external battery current sensing.

With kind regards,
Thiemo van Engelen

3

Thank you for your response.

I followed your instructions and did the following test.

First, I removed the MPPT 75/15 from the VE.Smart Network and switched off both MPPTs.

I then added the SmartShunt to the VE.Smart Network and switched on the MPPT 100/30.

After a few seconds, I saw that the MPPT 100/30 was receiving:

temperature from the Smart Battery Sense,
battery voltage from the SmartShunt,
and battery current from the SmartShunt.

So, the MPPT 100/30 can use the external battery current sensing when it is the only MPPT in the VE.Smart Network.

Then I added the MPPT 75/15 back to the VE.Smart Network and switched it on.

After that, I saw that the MPPT 75/15 was receiving both voltage and current sensing from the SmartShunt.

However, the MPPT 100/30 was no longer receiving current sensing from the SmartShunt.

This seems to confirm what you explained: when both MPPTs are in the VE.Smart Network, only one MPPT uses the external battery current sensing as the charge master.

My question is:

The MPPT 100/30 is connected to my two 150 W solar panels (300 W total). These are my main solar panels, and I can adjust their direction toward the sun.

The MPPT 75/15 is connected to my smaller solar panel group.

Therefore, I would like the MPPT 100/30 to be the charge master.

Is there a way to manually select the MPPT 100/30 as the charge master in a VE.Smart Network?

If this is not possible, how does the VE.Smart Network decide which MPPT becomes the charge master?

Thank you for your help.