Not sure if the 3300 operates the same but I have the 7002 and I have it set at 14.7 volt (snow flake icon) which is supposed to be good for cold batteries and AGM batteries but apparently not all. The manual says consult with your battery manufacturer.
I've used this charger on this setting for three years since my car was new. I've never had a low battery warning or any other issues with my battery so I'm happy
If my car is going to sit for a day or two which happens often, I keep it on the charger.