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brassmonkey001 avatar image

Low temperatute cut off?

It's starting to get cool here so I'm thinking about my LiFePO4 batteries. I have a Victron 100/50 MPPT and a Bmv712 connected via VE network and I have the BMV temperature lead connected to a battery terminal.

The MPPT is set to 5°c cut off but can you confirm this will prevent any charge going to my batteries until they get above 5°c?

MPPT - Solar Charge ControllerBMV Battery MonitorLithium BatteryTemperature Sensor
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5 Answers
dellmassive avatar image
dellmassive answered ·

The MPPT will cut the power charging the battery provided the MPPT is set to the Lithium mode and is receiving the Temp information via VE-Smart,


I tested that here > https://www.t6forum.com/threads/lithium-lifepo4-12v-batteries-time-for-an-upgrade.11157/page-5

But if you are using a DC-DC charger, or other. You will need to use the BMV output relay to be set as a low temp disconnect and connect that to a inline relay or trigger a Battery protect to prevent other charge sources . . . again tested here:

https://www.t6forum.com/threads/lithium-lifepo4-12v-batteries-time-for-an-upgrade.11157/page-5


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Thanks dellmassive, that's brilliant! I also have the Valence U27-12XP batteries albeit mine are the older version, but the fact you have a similar set up to me gives me confidence.

blond2silver avatar image
blond2silver answered ·

Hello.. I was wondering the same, but the system I have includes a ColorControlGX or CCGX that acts as a gateway, and has functionality for controlling the temperature with a parameter called DVCC "STS" (shared temperature sense).

If you do not have a CCGX, then "I think" the VictronConnect application via bluetooth can be utilized as a method of connecting the BMV to the MPPT with "VE.Smart Networking". I was reading about this method whereby creating a network first with the BMV configuration options (the little cog or gear), and then joining the MPPT from the netword defined with the BMV. There is a setup/configuration with the MPPT to set the low temperature cutoff. Anyways, I haven't implemented this method, because I have configured using the CCGX gateway as a controller. Hope that helps...

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

If you use lithium batteries you also should have a BMS (Battery Management System), external or inside of the batteries. This BMS will cut off any charge/discharge if something is wrong with the battery cells or temperature gets to high/low.

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My batteries have an internal BMS but I am not certain it has the ability to cut the charge at low temperatures.

Lucas Mill avatar image
Lucas Mill answered ·

As I know, the LiFepo4 battery can afford low temp even below 0℃ to -40℃, can you equip a customized BMS to prevent the low-temperature condition? such as protection of cut-off at 5℃ or -5℃, or you can set the alarm of specific temp.

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brassmonkey001 avatar image
brassmonkey001 answered ·

Thanks blond2silver, I have connected them via VE.Smart Networking so the BMV should tell the MPPT what the temperature is, I am just looking for confirmation that the MPPT will act on that information and not charge the batteries until the temperature has risen.

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