Back in AZ

Monday - Spent most of the day flying. For some reason, it’s exhausting to just sit on the plane.

Tuesday - Today’s small project was finishing the battery heater. I used a piece of the ½” rigid foam under the batteries and cut a small indentation where the wires connected to the 25watt silicon heating pads. I wired the pads to the temperature controller and placed the thermocouple between the two batteries about 3” from the bottom. The placement of the thermocouple is all a guess on my part. I will be able to compare four separate temperature measurements. One from the Victron shunt which measures the positive battery post, the thermocouple temperature displays on the controller, and the internal sensors inside each battery which I can see with Bluetooth using the app. Right now, the battery BMS is 22°C, the controller reads 22.4°C and the Victron is 23°C. I’ll try it during a charge cycle when the battery heats up internally. 

This very inexpensive temperature controller just has a relay to turn the heat pads on and off. I may make an ESP32 based controller which will use PWM to vary the temperature of the heat pads themselves. 

Wednesday - After spending the afternoon with friends, we went to the hot tub to relax and warm up. After the sun sets, it cools down pretty quickly. At 7pm, it’s only 51°F which may sound warm but it’s about 20°F cooler than todays high temperature. 

This morning, I tried to make an RV reservation at the next Albuquerque Balloon Fiesta next October but after waiting in the queue, they were all sold out in 30 minutes. 

Thursday - About the only productive activity for the day was grocery shopping. Nothing exciting about that but that’s not why we are here. It’s a bit warmer here than back home and we enjoy the travel.