I ran outside in the cold in a t-shirt on a ten degree night to check. 🔋 

12.77 volts on the starting battery, 12.82 on the two accessory battery, both with no load. Figuring a little line drop and the fact it’s ten degrees out, I’d say those batteries are about as charged as you will get them. I usually don’t see voltages like that on the starting battery except after a full day on the road. 

To be fair, I think the batteries were close to full when I parked last night but it’s still a cold night and the various vampires (always on loads) have been nibbling away at the electrons since I parked yesterday. 

Yes, I know it’s not normal to run outside on a ten degree night to check battery voltage down to the hundreds of a volt on a truck your not planning to start. But it’s so fun to see that mess of wires, relays and brain boxes is working properly.