Hi Tim,
The cold really slows things down, especially if there are weak areas in the electrical system that normally would not show themselves in warm weather. Things not helping our old bikes are dirty connections. Corrosion puts a lot of resistance in the system. Clean the ground at the frame/engine. Clean connections from the regulator/rectifier. Even though it's a new battery check and clean the terminals again. After cleaning use some di-electric grease on the connections to keep them from corroding again.
Do you have a multi meter? You can check your charging system with the "electrical fault finding chart" found in the filebase here, and start going thru the list. It's possible the battery isn't getting charged very well. Check the voltage across the battery terminals at idle, you should have about 12.5v Then get the rpm's up to 2500 and the voltage should be about 14.5v
Is your charger one of those "smart chargers"? They are great. You can't overcharge a battery with one. Just keep an eye on the water levels and only use distilled water to top off a battery.
One other thing comes to mind, are you using the proper weight oil? Thick cold oil can slow down a starting engine. Try the lightest weight recommended in the manual.
Oklahoma City, OK
78 KZ650 B2 82,000+ miles
