Be very careful since the batteries are very expensive. The below is from Battery University
"...Advancements are being made to charge Li-ion below freezing temperatures. Charging is indeed possible with most lithium-ion cells but only at very low currents. According to research papers, the allowable charge rate at –30°C (–22°F) is 0.02C. At this low current, the charge time would stretch to over 50 hours, a time that is deemed impractical. There are, however, specialty Li-ions that can charge down to –10°C (14°F) at a reduced rate..." The LFP batteries on our Roadtrek have 4.8 kW-hrs capacity so the maximum rate would be about 100 W.
We have 4.8 kW-hrs in our Roadtrek. The battery suite is directly below the sleeping platform. Our son, who has been in alternative energy since the 1980s, designed and fabricated our system. He installed a small fan to pull in air from the main cabin and blow it over the two batteries (Manzanita Micro made of CALB cells) for both cooling in summer and warming in winter. We just put a remote thermometer (the kind you buy for $15 at any hardware store) to know what the temperature is at batteries.
One can install small 30 to 50 W lamps in vicinity of the batteries to keep temperature above freezing. Others are placing the batteries on small heating plates designed to keep the holding tanks from freezing.
Reed and Elaine
|