I've had an EVO2 for almost 2 years. I got the specific charger but haven't needed to use it yet. The battery is temperature sensitive, ie it needs to be warm or warmed up to have good CCA. When it is below 45 - 50F, it's output is low. You will get some internal heating by putting a load on it. Once you do that, you will get enough CCA to start.
Since I don't do cold weather driving, no problem.