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).