Are the BMS's in batteries sufficient to prevent cold weather charging?

[myusername134]

Example: Litime 48V 100Ah LiFePO4 Lithium Battery - it has a BMS. Do essentially all BMS satisfy the role to prevent the battery from charging in cold weather?

 

[sunshine_eggo]

Example: Litime 48V 100Ah LiFePO4 Lithium Battery - it has a BMS. Do essentially all BMS satisfy the role to prevent the battery from charging in cold weather?

No. It's a specific feature, typically called something like "low temperature charge protection. not sure about LiTime.

 

[BentleyJ]

You cannot assume that ALL BMS have low or high temp monitoring. The information should be in the product datasheet otherwise the only way to know would be visual inspection to verify there is temp probe attached to the BMS. Even then you don't know if both high and low temp is monitored without specific call-outs on the product literature.

 

[jasonojordan]

As others have stated. Not all BMS have low or high temp protection. Not all that claim to have it actually do. This is how some brands stating same voltage, capacity, and output specs can very drastically in price.

When I picked up some 12v ones that I needed to know for sure had the protection I watched alot of testing videos from Will Prowse and went with ones he tested and recommended. If you are not opposed to taking a risk and ordering some you can test the function of these features yourself.

 

[B Tschacher]

I'm sure others have looked into this issue and I'm also sure few people are willing to purchase a BMS on the assumtion it has the desired and needed features. Then there is the issue of purchasing a BMS and finding out it isn't up to the tasks needed, then what? I'm making plans to invest a sum of funds I have very little of to get updated in my system of FLA's that have reached their end of life phase. I live in western S.D. and do not snow bird but do live full time in my 34 ft RV off grid in town. So I'm going to have to look at BMS's and find something that has the features to turn on and off heaters to maintain a suitable range to keep the new LFP's from crystalizing and dying. I'm open to recommendations if anyone has them. My only other option would be to assemble circuit boards with thermistors and hope they perform as needed and I really don't want to take the gamble.

 

[yodamota]

glad this question was asked. I assumed if they had a bms they would have low temp shutoff.

 

[HRTKD]

My preference is to keep the batteries warm enough all the time so that they can take a charge at any time. If you go with a battery with an internal warming system, it warms the battery only when a charge (from PV usually) is available. So overnight the battery gets cold and then takes an hour or two to come up to temp once the sun is up, which means you're missing valuable charging time.

My Overkill Solar BMS does have a low temp cutoff for charging. I have it set around 33°F. The warming system keeps the batteries between 35°F and 45°F.

Will tested a couple batteries/BMS that failed the low temp cutoff test.

 

[Mirlen]

It's quite astonishing how many do not have low temp cutoff. A simple NTC thermistor is so freak'n cheap that it's gotta just be laziness and lack of understanding, which is scary...