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brassmonkey001 avatar image
brassmonkey001 asked

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 5ยฐc cut off but can you confirm this will prevent any charge going to my batteries until they get above 5ยฐc?

MPPT ControllersBMV Battery MonitorLithium BatteryTemperature Sensor
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5 Answers
dellmassive avatar image
dellmassive answered ยท

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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brassmonkey001 avatar image brassmonkey001 commented ยท

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.

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blond2silver avatar image
blond2silver answered ยท

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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brassmonkey001 avatar image
brassmonkey001 answered ยท

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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lucas-mill avatar image
lucas-mill answered ยท

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

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ยท

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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brassmonkey001 avatar image brassmonkey001 commented ยท

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

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