Quote Originally Posted by Eggman View Post
Now I'm not sure but I wonder if this is to recharge the battery following the discharge associated with the motor start?
It's not unusual to see >15v right after starting. IIRC some cars will recharge the batteries at a very high current rate, 50 amps or more. As for slightly higher voltages in the winter, that's normal as well. More electrical systems are likely active at the same time, heat, defrost, wipers, seat heaters, etc. Again, higher voltages are normal with a battery being charged.