slo ride

Ok, you drug it out of me. Pretend like I resisted. Supercapacitors. or ultra capacitors or double layer capacitors or aerocapacitors or whatever they are being called by the place you get em. Digikey or other electronic parts suppliers carry them. A little expensive but they are still a cottage industry that is just finally starting mass production. They are made from carbon aerogel, an ion permeable membrane and an electrolyte. 7Farads in the size of your thumbnail, 350Farads in the size of a D cell. 2.7V and 2600F in 138mm x 57.7mm at 470 grams. Kind of large but 4 in series for 10.8V supplying 10A or 108W would discharge 95% in 140 minutes. 2.5 HOURS of flying! Or if you got a really big one draw 80Amps for 17.5minutes. All from a 4lb pack that costs about $216, lasts over a million charge/discharge cycles, holds its charge for weeks, recharges in a few minutes if you can supply enough current. A 5 cell pack can be plugged directly into your car battery with no charger needed. Heck, it will start your car, and its not bad for the environment. You might want to check my math, it was done pretty quickly but it sounds right. Like everything, there is a catch. It is a cap afterall so the voltage will drop steadilly as it discharges. You'll probably want to keep at least a small battery to prop up the voltage and/or run the receiver and servos. But the really cool thing that I want to do is build the aircraft itself out of the capacitors. The carbon aerogel is available in paper like sheets. Cut it to shape to fit between the ribs and spars of the wing, add the membrane, 5M KOH electrolyte, foil terminals, then wrap the whole business in mylar, apply vacuum, seal the wing, then apply forming voltage to the terminals. Wadda ya think?
slo