question

Mark avatar image
Mark asked

Multiplus Charge Voltage Temperature Correction Coefficient

1- What is the exact charge voltage temperature correction coefficient programed into a Multiplus (as default)?

I can't seem to find this documented anywhere, apart from the graph in the appendix pages at the back of the manual. Based on this graph I have roughly calculated it but would like to confirm 100% - as the graph may only be pictorial.

2- Is there any way to update the Multiplus charge voltage temperature correction coefficient?

I have had another look in VE Configure today but couldn't find a setting to configure it.

Thanks in advance, Mark.

MultiPlus Quattro Inverter ChargerTemperature Sensortemperature compensation
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Mark avatar image
Mark answered ·

I just updated VE Configure 3 and am VERY PLEASED to see that the Mulitplus/Quattro charge voltage temperature compensation coefficient can now be user configured.

Thank you very much @mvader (Victron Energy Staff) and @Margreet Leeftink (Victron Energy Staff)!

As installers/users can now configure the specific/recommended voltage temperature compensation coefficient, batteries will now receive the ideal/correct charge voltage at all temperatures.

It should also assist with balancing/prioritizing off grid systems where MPPT & Mulitplus/Quattro charge simultaneously, but are still controlled by their own independent logic/charge curve.

Does this also require a Mulitplus/Quattro FW update to function? (I have not yet tried to update my real system yet)


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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ commented ·

Mornig Mark, You’re welcome.

It does need a fw update of the inverter/charger, 460.

which is on its way; maybe next week; and otherwise in a month.


Matthijs

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Mark avatar image Mark ♦♦ mvader (Victron Energy) ♦♦ commented ·

Good morning.

No problem, that's great. Thank you again! :-)

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Margreet Leeftink (Victron Energy Staff) avatar image
Margreet Leeftink (Victron Energy Staff) answered ·

The voltage/temperature chart can be found all the way in the back of the manual. In the Appendix section.

The coefficient cannot be changed.

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Mark avatar image Mark ♦♦ commented ·

Hi Margreet, thanks for the reply.

Yes, as per my question I know about the temperature compensation chart in the back of the manual.

I have also visually picked up 2 points to approximately calculate the coefficient.

I would like to know the EXACT coefficient number, as used in the Multiplus internal calculations.

I would also like to request for this coefficient to be visable & user configurable in a future update of VE Configure. (Similar to MPPT setup in Victron Connect).

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Margreet Leeftink (Victron Energy Staff) avatar image Margreet Leeftink (Victron Energy Staff) ♦♦ Mark ♦♦ commented ·

The coefficient is 16mV per degree C.
We are looking into making this coefficient user configurable, but it will take quite some time before this feature will be added. It is on the wish list.

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Mark avatar image
Mark answered ·

Hi @Margreet Leeftink (Victron Energy Staff) & @mvader (Victron Energy Staff),

Now that the default charge voltage temperature compensation coefficient on a Multi has been confirmed to actually be 16mV/°C for a 12v bank = ~2.7mV/°C per cell - this is lower that the typical temperature correction coefficient specified for most lead acid battery types.

I don't know if any progress has already been made on this topic, but could you possibly place some priority on making this coefficient user configurable in VE Configure?

Thanks in advance, Mark.

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Mark avatar image Mark ♦♦ commented ·

Hi @mvader (Victron Energy Staff),

As you may know, a few weeks ago @Margreet Leeftink (Victron Energy Staff) assisted to confirm/inform me that ACTUAL default Multiplus temperature compensation coefficient is now -16mV/°C (for a 12v battery bank = -2.66mV/°C per cell).

As this 'new' coefficient is much lower, it could pose a risk of excessive charge voltage during high battery temperature conditions (compared to the recommendation specification for most lead acid batteries).

The new/lower coefficient also contributes to difficulty with 'matching'/'compensating' for multiple charge sources (because the different charge sources use a different coefficient any 'offset' applied will only work at a particular temperature).

Is making this coefficient 'user configurable' via VE.Configure something that could be implemented in the near future?

I do hope that you take this on board as positive & constructive feedback.

Thanks in advance, Mark

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Dale avatar image
Dale answered ·

Hi all,

I want to ask a question regarding firmware. I wish to update from:-

Product id 2624


Firmware version		 408

I think I have the correct firmware but just wanted to check as its the first time I have done this, I currently have 2624460.vff downloaded ready to go.

is this correct?

I am an electrical enginneer by trade so this should be pretty straight forward to do.


Thanks in advance

Dale

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Guy Stewart (Victron Community Manager) avatar image Guy Stewart (Victron Community Manager) ♦♦ commented ·

That looks correct.

It is now advised to use VictronConnect to update VE.Bus firmware, the method is here - https://docs.victronenergy.com/victronconnect-vebus.html#firmware-updates

The now-depreciated VEFlash method instructions and step by step video is here - https://www.victronenergy.com/live/updating_firmware:updating_ve.bus_products

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