I would probably want a block heater in -17F temperatures.

Ive had my red top since october 2005 and its doing ok. Its went dead a few times(slap dead) but that wasnt the batteries fault. Reason I say its doing ok is its not done anything special yet. If it lasts more than 5 years Ill say its a good battery.

Volts on my battery is ~12.3 before I start it. Runs around 14.4volts with the engine running.

_________________
LOST KJ'S
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Current Jeep: 2004 Jeep Liberty
-Atlantic Blue
-Air Ride Rear Suspension ; OME/Rustys Lift ; Powertrax Locker ; Moog Lower Ball-Joints ; 245/70/16 Yokohama Geolander A/T-S's on MOABS ; Flowmaster 50 SUV
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http://www.cardomain.com/id/jeepjeepster

Another option for extreme duty (very cold to very hot temps, lots of draw-downs, etc) is the Odyssey PC1500DT. Pricey, but so far it seems to be a dang good battery. Mine has had no problem cranking my KJ at -40F. This is the second winter I've had it in and I'm happy with it so far.

http://www.odysseybatteries.com/battery/pc1500.htm