Can cold weather kill a car battery?
Most car/truck batteries will/should have an open circuit voltage of 12.6 volts. If your battery discharges over a period of time, which can happen with simple parasitic (such as a on board CPU) or possibly leaving an interior light on, this will cause the battery to discharge.
Most modern cars have a current draw due to the cars electronic systems, which means they will go dead in a few weeks if not ran. If a weak (low charge or discharged) battery is left to freeze it will ruin the electrolyte and even push plates together and cause a short.
When a batter is fully charged it has a specific gravity of 1260 (this is the measurement of sulfuric acid) this measurement can be checked with a hydrometer, when the battery discharges the sulfuric acid goes through a chemical reaction and becomes more like water and would measure a specific gravity of 1000.
If water freezes at 32 degrees F and your battery was completely discharged, then it is fair to say that your battery froze solid like an ice cube.
Once this happens, the battery is 99% unrecoverable. Your trickle charger would be useless on the battery.
When you replace your battery, you should have your charging system checked out. This can be done at Good Guys Diesel.
In the future, if you plan to leave the vehicle longer than 4 weeks, you should disconnect the negative cable from your battery. This will eliminate any parasitic charge.