I had been watching the weather and it held true for Thursday, December 15, 2022, Clear, Calm and Cold, 34 degrees when I started the First Legal Eagle. My goal was to fly both Legal Eagles and test out some new clothing to keep me warm when flying in the Winter. I have been wondering why motorcyclist can ride on these cold days and stay warm, thru my son-in-law I have met someone in the Business that knew what I needed. I have spent money in the past with little success in keeping warm. This time we hit the jackpot. I was wearing a Block jacket and pants and glove liners. Block is made to block the wind and insulate. It works. I did not fly for a long time but I was warm and the wind and body temps were great. I wear a long tailed windbreak when it is cool outside, it has good pockets to hold things and provided just the right finishing touch to keep me warm. Block is sold thru Cycle Gear and is well work the cost, not any different than thermals except it blocks the wind and keeps you warm.
The other thing I learned the hard way this morning, I was shooting video with a Gopro Hero 10, Love the camera but the battery life is not very predictable or reliable. Normally I get 45 to 50 minutes of recording time and since these flights were so short was sure the battery would do it. I did not replace battery with a fresh one after the first flight, like I should have and second flight stopped recording shortly after starting to taxi out.
The other item I am learning is Lithium batteries work great when they have proper charging system attached. I had a large lithium battery in ORV and with the testing we have been doing one the Briggs and Stratton, to save weight removed the Charging system, cannot use with alum. Flywheel. I started the engine 50 to 75 times with no problems, then charged it with a standard 12 volt car battery charger, forgot and left the instrument switch on and did not check for a few days, battery volts went down, way down, and it did not work so went to new small, very small lithium battery and got the correct charger for lithium batteries. This morning in the cold it cranked a bit longer than normal and voltage went way down, thought the battery was a goner but it took a charge and later in the day seemed to take loads with no problems, time will tell. Lithium as I understand needs about 13.5 volts to charge and should never go below 11 volts. The should not be in location where temperatures are high or low and do not like vibration. I question what these conditions are, if they are made for motorcycles and cars in the real world don’t temps and vibrations, pumps ETC. enter into what happens?
Legal Eagle Flying Adventures 
Li-ion batteries are amazingly light and can now deliver high currents for starting applications. When properly cared for they will also last longer than Lead-Acid batteries. They do have their own shortcomings and can be rendered unusable if mistreated. Li-ion batteries have a very low self discharge rate, they don’t need to be trickle charged and actually trying to trickle charge them can damage them permanently. Using a Li-ion only charger with the correct charge technique (or the charging system from the engine) is the safest way to avoid charging damage. They can also be permanently damaged by over discharging them. The best way to avoid this problem is to use batteries with a BMS (battery management system). The BMS will protect the battery from abuse by disconnecting itself from the charger or load if an out of bounds condition occurs.
One area where Li-ion does not perform as well or better than Lead-Acid is cold weather. If the battery temperature drops below freezing, especially below -20C, they just can’t deliver the high currents. For most ultralight pilots this shouldn’t be a problem as they don’t want to fly when it is this cold anyway. Since the batteries are so small and light a solution to this is to bring the battery home in cold weather and keep it at room temperature. When you go to fly, re-install the battery and start your engine, the battery should crank just fine as it should still be warm. If you won’t be flying in the winter and the battery would otherwise be exposed to below freezing temperatures it is a good idea to remove it and bring it home to a room temperature environment.
All this is also true for the batteries in your phone, tablets, laptops and action cameras. If you can keep your phone warm by keeping it in an internal pocket next to your body it should be fine. For the other devices, keep them indoors until you are about to use them so the batteries start out warm but if the batteries cool to 0C or below they will quickly go to zero state of charge. Warming them back up usually doesn’t fix this, you need to warm them back up and then re-charge them.
Hope this helps.
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