Add Low Temp Sensing $$

[Rbertalotto]

What is the most cost effective way to protect Lithium batteries that do not have low temp charge sensing?

Electric heat pad?
Victron charge controller with low temp?

Are there any add on devices that can be used for this. I want to install two, 100Ah lithum batteries in my travel trailer and leave them in all New England winter. And I sometimes camp where the temperature will go below 32d F.

Or just buy SOK batteries and be done with it. they are now $559 each. Are there any other options for Lithium with low temp for less$$?

 

[Samsonite801]

What is the most cost effective way to protect Lithium batteries that do not have low temp charge sensing?

Electric heat pad?
Victron charge controller with low temp?

Are there any add on devices that can be used for this. I want to install two, 100Ah lithum batteries in my travel trailer and leave them in all New England winter. And I sometimes camp where the temperature will go below 32d F.

Or just buy SOK batteries and be done with it. they are now $559 each. Are there any other options for Lithium with low temp for less$$?

First of all, don't think of heat pad as last line of defense. Think of heat pad as in, to allow you to operate (charge) in the freezing territory, you should still have a last line of defense like BMS or charge controller with low-temp sensing as a fail-safe to stop the charging in case the heat pad circuit fails.

On my 12v system I bought a Victron 250|100 charge controller, but note that the factory internal temp sensor only takes daily readings for low temp (in between solar cycles), so you have to add in the external temp sensor option in order to get realtime monitoring, in my case I purchased the 'Victron Energy Smart Battery Sense (Bluetooth)', which has a temp probe built-in, and when you connect it to the charge controller it provides realtime temperature monitoring, so you can set charging low temp cutoff.

Ref:

Amazon.com: Victron Energy Smart Battery Sense (Bluetooth) : Patio, Lawn & Garden

Amazon.com: Victron Energy Smart Battery Sense (Bluetooth) : Patio, Lawn & Garden

www.amazon.com

or:

Amazon.com

A good BMS should also have low-temp charging cutoff... Should have some type of temp probe coming off the board, directly contacting a temperature sample point on the cells.

Another option might be to buy the Battleborn batteries with the heater option, and they have both heat pads and the BMS has low temp charging cutoff built in. They do cost more though, but they come with a 10-year warranty which makes them very appealing in the 'turn-key battery' arena.

 

[Rbertalotto]

Thank you for the info..... I'm currently using an EPEVER Tracer 4210AN charge controller which has a battery temperature probe. You would think the manufacturers that build devices that offer this feature and are designed to charge Li batteries would add a few more components to facilitate low temp shut down......
I think my best course of action is to do the math.....Inexpensive/non low temp sensing batteries and replace the CC with Victron.....Or leave the solar CC as is and buy the more expensive temp sensing batteries..... Without pencil to paper it looks like the $$ will be the same.

​

 

[Samsonite801]

Thank you for the info..... I'm currently using an EPEVER Tracer 4210AN charge controller which has a battery temperature probe. You would think the manufacturers that build devices that offer this feature and are designed to charge Li batteries would add a few more components to facilitate low temp shut down......
I think my best course of action is to do the math.....Inexpensive/non low temp sensing batteries and replace the CC with Victron.....Or leave the solar CC as is and buy the more expensive temp sensing batteries..... Without pencil to paper it looks like the $$ will be the same.

​

What blew me away is how it seemed so many manufacturers, the cold-temp cutoff wouldn't actually work. Like back when I would watch several videos Will Prowse would publish about a BMS, battery, or something, and the manufacturer would say BMS supports overvolt/undervolt, temp control, but usually the temp part it would only stop on overtemp, and when Will would test low-temp cutoff it wouldn't actually work.

It seems this is a critical situation in which you would want it to work (since this kills LFP cells, charging below freezing temp), and the early BMSs seemed to never address this (and some would even advertise that it supports low-temp cutoff but wouldn't actually function when tested).

Seems they are getting better with it on some of the newer stuff, but for this reason, I would recommend actually testing it yourself by dipping the temp probe in ice cold water and checking to confirm the charging stops and know what temperature it stops at.

It gives some extra peace of mind to actually know you tested it and it works as your failsafe so you can rest assured that your battery investment isn't at risk.

 

[Rbertalotto]

The other thing is there are solar charge controllers with low temp shutoff......But I'm not aware of ANY shore power chargers that offer this feature. I need to find out if the Victron shunt battery monitor offers it as all charging would go through the shunt and that would be a great failsafe even if the batttery offers it.

 

[Samsonite801]

You could even make one using a relay and temp probe / logic board if needed....

 

[Rbertalotto]

I thought about doing that.....