Classic LiFePO4 - Low Temperature Cutoff

[bdimambro]

Is there or will there be an option for a low battery temperature cutoff much like the high-temperature cutoff setting to prevent the Classic from charging LiFePO4 batteries when at or below 32F?

Thanks,

Brian

[ClassicCrazy]

Is there or will there be an option for a low battery temperature cutoff much like the high-temperature cutoff setting to prevent the Classic from charging LiFePO4 batteries when at or below 32F?

Thanks,

Brian

That would be great wouldn't it ?
In the mean time you could probably set something up to do that  using Arduino or Raspberry Pi .
Larry

[bdimambro]

Thanks for the suggestion!! I think I'll have a look at the Pi threads.

Brian

[ClassicCrazy]

I forget the best way to do a low temperature cutoff.   You would set up a solid state relay in the PV input line and have something on its control  open it up is one way. That wouldn't need an AUX and come to think of it a simple thermostat sensing the battery temperature could do that and automatically reset too .  You would only need the Arduino or Pi if you wanted to write some smarter logic to control it . You could do that in a Pi using Node Red which also can send email notifications if you wanted it to .
But a thermostat would sure be easiest .
Steve in another thread on here was talking about a BMS for Lithium batteries that the manufacturer was taking input from users to add features. I wonder if that BMS already has a low temperature cutoff built into it ?

Larry

[Steve_S]

Most semi-respectable BMS' have Lo & Hi temp cutoffs. 
Cutoff threshold for LFP is 0C/32F, and preferably lowered charge rate up till 10C/50F.
Exception exists for Yttrium Doped LFP for Cold Temp use (quite $$$).

The majority of Prebuilt battery packs also use BMS' which have Hi & Lo temp cutoffs but some have LO as an option (which is really ridiculous).  Some Prebuilts also have Battery Warmers as well.

There are two basic types of BMS'.  FET Based or Relay/Contactor based.  Those with relays can also be configured to interact with more advanced Solar Gear.  For example, a Samlex EVO Inverter can take the relay signals to cut off charging or inverting from the BMS, they actually use their Temp Sensor circuit to do that and a change in it's programming.  A simple enough & elegant solution.

I use Chargery BMS' in all of my battery packs.  These are Smart BMS' that use Relays/Contactors, I am using SolidState Contactors which draw very little power.  The Next Generation "P Series" is presently in testing before release.  These will come with Active Balancing, RS232/RS485/CanBus protocols plus a few more features, most of which is a result from user input & feedback.  These are expected to be available fairly soon.