question

Tom Ranson avatar image
Tom Ranson asked

Multiplus ii and MPPT chargers low temperature cut off for LiFePo4

Hi all,


I can't seem to find the answer to this on the forums or elsewhere.


I am planning to install LiFePo4 batteries for my existing Multiplus ii and 30/100 MPPT's. The batteries I am considering (Ultramax) do not have low temperature cut off built into their BMS.


I believe that the MPPT's can be configured with low temperature cut off when used with a Smart Battery Sense. This seems easy enough to configure.


But what about the Multiplus ii? I can't find out how to achieve this.

Multiplus-IIMPPT Controllers
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2 Answers
xavier-64 avatar image
xavier-64 answered ·

The best is to place a battery sensor on the battery with the Multiplus temp sensor input.

Xavier

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Tom Ranson avatar image Tom Ranson commented ·
@xavier-64 yep, I already have the included temperature sensor installed. I was struggling to find the option on the Multiplus to configure the low temperature cut off.
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klim8skeptic avatar image
klim8skeptic answered ·

You have a Cerbo?

Have a read of the DVCC manual , you can use STS to share temperature data between devices. Set your chargers to disable charge below 5c.

SVS and SCS might be useful also.

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Tom Ranson avatar image Tom Ranson commented ·
@klim8skeptic Yep, have a Cerbo. Already have DVCC configured with STS, SVS and SCS enabled.


But how to I enable the low temperature cut off on the Multiplus? It's quite obvious on the MPPT's.


Oh, wait- I think I've found the setting in Ve.Config, on the charger tab.


Presumably I have to configure low temperature cut off on both the MP and all the MPPT's separately.


Is there any advantage to having a Smart Battery Sense networked to the MPPT'S, or does STS (plus SVS, SCS) just take care of this using the temp sensor wired to the MP?

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klim8skeptic avatar image klim8skeptic ♦ Tom Ranson commented ·

Is there any advantage to having a Smart Battery Sense networked to the MPPT'S, or does STS (plus SVS, SCS) just take care of this using the temp sensor wired to the MP?

You can use the temp sensor for the multi, for STS data to the mppt. Or as a lot of ppl do, use the multi's temp sensor directly to the Cerbo.

Note, dont use DVCC and Smart Networking at the same time.

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Tom Ranson avatar image Tom Ranson klim8skeptic ♦ commented ·
@klim8skeptic how can I verify if the MPPT's are receiving temperature data from the Multiplus connected sensor?
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klim8skeptic avatar image klim8skeptic ♦ Tom Ranson commented ·

how can I verify if the MPPT's are receiving temperature data

Given that my temp sensor is connected to my Venus, I can see the battery temp locally with bluetooth, or remotely with Victron Connect via VRM and the internet.

victron-connect-temp.png

The multi also receives temp data from the Venus, and can be viewed via remote console.

vrm-multi-temp.png

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victron-connect-temp.png (150.2 KiB)
vrm-multi-temp.png (66.8 KiB)
Tom Ranson avatar image Tom Ranson klim8skeptic ♦ commented ·
@klim8skeptic perfect thank you
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