what to do with batteries for a cold northern ontario winter

[johnmorin]

What do most people do with their batteries in extreme cold climate in the winter where the temperature will dip to -40 celcius occasionally and -25 is pretty constant for about 2 months. I am using lead acid batteries, 10 6v 205AH. I will be using the system lightly maybe four times over the winter. I can also do without the system for the winter. Thanks for your feedback

[lkruper]

What do most people do with their batteries in extreme cold climate in the winter where the temperature will dip to -40 celcius occasionally and -25 is pretty constant for about 2 months. I am using lead acid batteries, 10 6v 205AH. I will be using the system lightly maybe four times over the winter. I can also do without the system for the winter. Thanks for your feedback

A fully charged flooded lead acid battery will not freeze above -69c

[Mike90250]

If the system is going to be idle for the winter, charge the batteries up, top off the electrolyte, and the next day, charge again to make sure it's all mixed well Hang a PV panel vertically above the snow line, facing south, or the most hopeful direction, and let the system float all winter, if you can, cut back your ABSORB time and Voltage, because the batteries are now in FLOAT service and not CYCLE service. Be sure to reset it all in the spring when you come back.