MadMacks
Off Gridder
I just received a Jiabaida SP04S034 BMS with heat control, Bluetooth, and a few other options. I downloaded the factory spec sheet so I could better understand when the heat element attachment port gets triggered. The factory manual shows the following…
![B6309EF8-F968-434E-9A2A-34E2988328DB.jpeg B6309EF8-F968-434E-9A2A-34E2988328DB.jpeg](https://diysolarforum.com/data/attachments/136/136406-195ecf87d6efe407f9bc6f5b5376c300.jpg)
This makes no sense to me. My understanding is that LiFePO4 cells should not be charged at or below 0°c. Why would a manufacturer set factory defaults for triggering a heating element to the settings shown above? OBTW the columns are minimum, typical, max. So, for example, if I read this correctly they’re saying for a BMS without heating post the low temp protection can be set to between -15°c and -5°c and is typically set to -10°c, all of which are guaranteed to kill the cells! For my unit, which has a heat post I can apparently set the parameter to between -3°c and 3°c. Again, why would a BMS even allow you to set a low temp value below 0°c?
What am I missing?
![B6309EF8-F968-434E-9A2A-34E2988328DB.jpeg B6309EF8-F968-434E-9A2A-34E2988328DB.jpeg](https://diysolarforum.com/data/attachments/136/136406-195ecf87d6efe407f9bc6f5b5376c300.jpg)
This makes no sense to me. My understanding is that LiFePO4 cells should not be charged at or below 0°c. Why would a manufacturer set factory defaults for triggering a heating element to the settings shown above? OBTW the columns are minimum, typical, max. So, for example, if I read this correctly they’re saying for a BMS without heating post the low temp protection can be set to between -15°c and -5°c and is typically set to -10°c, all of which are guaranteed to kill the cells! For my unit, which has a heat post I can apparently set the parameter to between -3°c and 3°c. Again, why would a BMS even allow you to set a low temp value below 0°c?
What am I missing?