There are three reasons why temperature can be an issue:
1. Charge Rate :: 2. Usable Capacity :: 3. Electrolyte Freezing
> Temperature vs. Capacity - Flooded Lead Acid Batteries
Modified on: Fri, 29 Aug, 2014 at 12:21 PM
Electrolyte : Here is a copy of info from: http://www.trojanbattery.com/tech-support/faq/
> 9. Can a flooded battery freeze?
The only way that a battery can freeze is if it is left in a state of partial or complete discharge. As the state of charge in a battery decreases, the electrolyte becomes more like water and the freezing temperature increases. The freezing temperature of the electrolyte in a fully charged battery is -92º F (-69º C).
>At a 40% state of charge, electrolyte will freeze if the temperature reaches approximately 16º F (-9º C).
Chemical reaction is slow at lower temperatures and so a higher voltage will be required to charge. See first post under charging: http://unveiled.info/index.php/solect/charging/