ransley wrote:
On Jan 20, 10:25 am, Boden wrote:
B'razeer Boobar wrote:
Past couple of years I didn't remove the sealed battery from the
lawn tractor which is kept in a detached garage. Winter temp in the
garage never dropped to 32F due to mild winters. There were no
problems the following springs. If the temp does go below 32 for a
sustained period, does this necessarily cause irreparable damage to
the battery?

Until the electrolyte freezes no damage will occur. When it freezes
it can cause the case to crack and leak, and possibly damage the
interior elements. Battery acid, depending on the state of charge,
won't freeze until it drops to -25 to -30 degrees F

A fully charged battery wont freeze until -75 a discharged battery
will freeze at 27 and it will sulfate and ruin the battery, with car
electronics and dirt on the battery they self dischage so the freeze
point goes up.

The freeze points are low, but ... they aren't consistant and outside a
lab I've never seen finite figures, only empiracal data. It depends on
too many things to state that a battery won't freeze until -xx degrees.
Every battery, especially from Mfr to Mfr, and depending on age/prior
use has different specs. It does seem pretty sure though that most good
batteries will last to below at least -30, often considerable lower.