Low-temperature charging protection is often normal
PV production can be available while a LiFePO4 battery is not accepting charge. Many battery systems block charging when the cells are below the manufacturer-defined temperature limit to protect the cells. Ambient temperature is not the same as the temperature measured inside the battery.
Check the battery before changing settings
Read the BMS status, battery temperature, state of charge, PV input and charger status. Then compare the result with the specific battery datasheet. Confirm that the MPPT controller or inverter/charger is using the correct lithium profile and is able to follow the BMS charge-enable signal where required.
Plan heating and winter autonomy together
A self-heating battery or heated enclosure needs an approved control method, insulation, power budget and maintenance plan. Heating energy reduces the energy available for the load, particularly at an unattended monitoring or telecom site. Do not bypass a temperature sensor or force charging below the battery supplier's limit.