A123 Battery Cells For Your Radio Control Model Airplane
Electric model airplanes have been established for roughly 30 years. A massive problem in the early days was battery energy density. Quite simply, they only weighed an excessive amount of for the level of juice you have access to out of them. This situation has improved dramatically recently using the coming of Li-Poly cells, but an electric battery pack for a larger model can simply cost hundreds of dollars. The arrival of electrical cars, like the Toyota Prius has spurred quantity of research into new battery technologies. In this article, I will describe a substitute for Li-Poly batteries that gives intriguing possibilities.
RC Lipo Batteries
A123 Systems produces Lithium-Ion Nanophosphate cells. These cells have a nominal voltage of three.3 volts and will withstand continuous discharge rates of 30C. They may be safely discharged as a result of 2.0 volts. The voltage remains fairly constant from the discharge cycle, but they have a clear drop-off by the end. Expect 300 cycles prior to deciding to notice any lowering of capacity while at 1,000 cycles you should have 75% from the original capacity. They're very safe and secure. Overcharging or higher discharging will not cause an outburst and will haven't much effect on living from the battery. Balancing cellular structure if they are charged continues to be advisable, but not absolutely required. They may be charged soon after use in Fifteen minutes.
Cellular structure are available in two sizes. The original M1 cell features a capacity of 2.3 Ah and weighs 70 grams (2.47 oz). A newer, smaller size holds 1.1 Ah and weighs 40 grams (1.41 oz).
The main source for A123 M1 cells may be DeWalt 36-volt portable power-tool battery packs. Each pack contains 10cells. I purchased a couple of these for $100 each through Ebay. The values appear to have gone up recently towards the $120-$130 range. Single cells can be purchased online for $15 from the growing selection of vendors. You'll find a couple of the smaller cells in a Black & Decker VPX battery pack which sells for about $15. Small cells may also be had for $12.50 each.
There are many Li-Poly chargers that support or can be modified to guide the charging of such A123 cells. Because of the sharp voltage drop-off when discharged, you may be best utilizing a timer when you fly. Otherwise you need your ESC to shut off of the motor when 2.0 volts per cell is reached.
Bottom line? These cells give you 70% the energy density of Li-Polys for around 45% with the price. For many people, this is a good trade-off. They are extremely safe and could be charged in 15 minutes. In the event you purchase half as many energy as a result of shorter charge time, chances are they be a much better value.
RC Lipo Batteries