On Sunday, March 18, 2018 at 11:29:30 AM UTC-4, Dan Marotta wrote:
I used LiFePO4 and charged them over the winter months in NM (lots of zub-freezing nights) using the chargers supplied with the batteries without any problems.

Thanks for reporting your first hand experience. Maybe your charger has a temperature sensor that stops charging below 32F.

I first came across the warning in the user manual for a combination
battery_charger+battery_isolator (www.westmountainradio.com 'Epic PWRgate') This device is programmable for LiFePO4 or AGM. The device uses a temperature probe to adjust charge rate. The device does not work with other Lithium based battery chemistry.

"West Mountain Radio Operating Manual Page 10

Optional Temperature Probe

The temperature probe provides valuable data for the Epic for charging. If the temperature of the battery is too high or low on a LiFePO4 battery, the Epic will cease charging the battery. For Lead-Acid batteries, the Epic will adjust the charge voltage dependent on the battery temperature. This allows for the most optimum battery charging.

If a probe is not used, be sure to never charge a LiFePO4 below freezing temperatures for safety reasons.

http://www.westmountainradio.com/pdf...ate-manual.pdf