Alternative Approach to Cold Temperature Battery Protection??

[crv0262]

I have recently installed a significant upgrade to my 12V System. This includes:
- Pair of Ampere LIFEPO4, 200Ah Plus batteries, that have a 200A BMS, but do not have cold protection
- Victron MPPT 100/30 Smart Solar Charger,
- Victron Energy Smart Battery Sense, Voltage and Temperature Sensor,
- Progressive Dynamics PD9160ALV 12V Lithium Converter/Charger - 60 Amp,
- Victron 30a DC to DC charger,
- Victron Energy Lynx Distributor.

Currently my Inverter is on Line 1 in the Lynx Energy Distributor, the MPPT is line 2, the DC to DC is line 3 and the Converter is line 4.
With the connection of the Energy Smart Batter Sense to the MPPT Solar Charge Controller (and the setting up within the app), this will protect my Solar Charger from charging the batteries below 32 degrees.

If I install a small busbar (2 port) and connect the PV/Solar and the Converter as input into the MPPT, would this provide Low Temperature protection for the batteries? (Excluding the DC to DC, which is rarely used, and never used with connected to Shore Power). Are there any issues with the converter power being an input to the MPPT (Similar to the PV)?

The challenge I am trying to address is that I live in Pennsylvania, and keep the camper plugged into shore power at our home. I didn’t want to spend the money on the Cold Protection batteries and wanted to keep the batteries in the front compartment. I know there are other solutions, but curious if there are any inherent challenges with this type of approach.

Thanks in advance!

[Soundsailor]

Your suggestion doesn't sound like a good idea to me. Instead, I would build an insulated battery box and add pad heaters controlled by a thermostat.

[Conner58]

I would just turn your converter off if you don't want to remove batteries for winter .

[sande005]

I would just turn your converter off if you don't want to remove batteries for winter .

This! Cold only really comes into play if you want to CHARGE your batteries when below freezing. To a lesser extent usage, down to about 5F (depending on manufacturer). But for unconnected storage, they should be fine to -20 below, based on some brand specs I've seen. Just make sure they are partially discharged (50%) for longest overall life.

[Conner58]

This! Cold only really comes into play if you want to CHARGE your batteries when below freezing. To a lesser extent usage, down to about 5F (depending on manufacturer). But for unconnected storage, they should be fine to -20 below, based on some brand specs I've seen. Just make sure they are partially discharged (50%) for longest overall life.

He leaves it plugged in all winter. So either need to remove them or put a heat source in or turn converter off .

[sande005]

He leaves it plugged in all winter. So either need to remove them or put a heat source in or turn converter off .

Or install a true main disconnect switch...or just disconnect wires at a terminal. Depending on the actual configuration, doing so he may be able to run most of the 12v items with the batteries disconnected, just using the output from the still otherwise functioning converter.
He didn't note what, if any, use he wants out of it while at home. Is it sitting cold and dark, or is it sometimes being used at home (and if so, what and how much)? Does it need to be ready-to-go fully charged for a mid-winter trip?

[crv0262]

Thanks all for your responses.

I was seeking to understand "why not". Is there a technical reason the converter can not be connected through the solar charger and use all the features the solar charger is already providing to protect the batteries.

I am aware of many of the alternatives I already have and could use:

a. I have a full battery disconnect, that I manually turn off to assure no charge when the temperature drops. I also have a disconnect for each power source (DC to DC, Solar, Converter)
b. I have a set of battery heaters (not yet installed) and am building an insulated battery box to help keep the temp above the 41degree threshold I have set on my Solar Charger.
c. I can run the needed 12V items (primarily lights), through the Shore Power set up as I have it configured

What primarily triggered this thought process was the Bus Bar approach (Lynx Energy Distributor) where all the Power Sources (Solar, Converter, Battery) and Loads (Primarily the Inverter) are all in a single bus bar. It would have been great if Victron built the logic that cuts off low temp charging, into the Lynx Energy Distributor (that it has in the Solar Charger) to enable it all the be managed at the distributor level

Thanks again -