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nigelfxs asked

CCGX Firmware 2.42 - change to source of voltage measurement?

I have noticed that, since upgrading my CCGX firmware from 2.34 to 2.42, my system now regulates the battery voltage approximately 0.3V higher than before. My system consists of a MPPT150-70, Multiplus-II (48V, 3kVA), CCGX, BMV712 and BlueNova 52V 12kWh Lithium battery.

My Lithium battery requires an float voltage of 55.5V, and since the CCGX firmware update, the system has been regulating the float voltage at 55.8V. I have double-checked that the Float Voltage setting in VE-Config is still set to 55.5V.

It appears that the system is now using the lower-accuracy "VE.Bus System [0] Voltage" for voltage measurement instead of the "Solar Charger [256]" voltage or the more-accurate BMV712. Note that I have configured the BMV712 as the "Battery Monitor" in the system.

Multiplus-IICCGX Color Controlvoltage
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3 Answers
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nigelfxs answered ·

Hi John

Thanks for confirming that it not just my system! I think I have found the answer - in the Venus OS Software Change Log for version 2.40 has the following:

DVCC, ESS & Scheduled charging:

  • ESS: use the inverter/charger as the source for Solar Charger voltage sensing – always.

My solution has been to adjust the Absorption and Float voltages in VE-Config to compensate for the 0.3V offset. So far it is working perfectly.

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JohnC avatar image JohnC ♦ commented ·

Good work finding that, seems you're sweet now.

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Warwick Bruce Chapman avatar image Warwick Bruce Chapman commented ·

Like great sleuthing.

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nigelfxs answered ·

Update: I have DVCC control enabled (my battery is compatible) and I had incorrectly disabled Shared Voltage Sense (SVS).

When you enable SVS, the system can then use the more-accurate BMV712 for voltage measurement - so you do not need to do any adjustments/compensation in VE-Config.

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JohnC answered ·

Hi Nigel. I haven't a direct answer for you, just some things to consider..

I too noticed 2.42 immediately changed my mppt's float V by about the same amount. I use temp compensation, and it was as though that was turned off. A 'reboot' of the mppt might do that, so I immediately resolved to let it see a new day. It recovered. Maybe that is your issue, if you're looking at immediate effects. You may not use temp comp though with Li's, but it may be related. (even turned on/off - check).

VE.Config is looking at your Multi's charger, not the mppt's. They remain independent (as they should), and you'll need to access the mppt settings if you've noticed this under solar charge.

All of the units in your system can measure their own V. You can compare them on VRM. I wouldn't worry too much unless they differ. So then find out why. V is a fairly easy thing to measure accurately, so if they differ, further investigation is warranted.

Just to kick you off.. good luck.

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