Hi Bob,

I fly both power plants but I tend to fly my EDFs more due to their simplicity and having to carry much less support equipment.

As far as less expensive batteries go, here's the scoop. There are 3 battery manufactures in the world that make the LiPo cells we use in the hobby. Battery companines that produce packs buy cells from one of these manufactures and the companies that are willing to pay for the premium cells (cells that are evenly matched in voltage and have low internal resistance) pay more for those cells. Thunder Power is one of these companies. The lower priced battery packs are from companies that buy the left over cells and their packs may not be made up of matched cells. When TP builds their packs, they match the cells to insure longevity of the packs. Heat is a killer for LiPo packs. The internal resistance of the TP packs are so low that they don't get much above ambient temperture after a 5 minute flight. A couple of months ago two buddies flew their EDFs back to back. The ambient temp was 92 degrees. One guy was using the TP packs BMV sells and the other guy was using some less expensive packs. The plane using the TP packs had a higher amp draw than the one using the other packs. After the flights the temp of the packs were measured. The TP packs were 105 degrees and the other packs were 130 degrees. Because of the lower temp of the TP packs, they will last much longer than the other packs and the lower temp is also an indicator of lower internal resistance. As witnessed at EJets last month, an airplane participating in the speed run qualifiers was lost due to a cell in the one of the packs going bad. Guess what, they were using "cheap" packs that couldn't keep up with the 150A draw of the setup they were using. Personally, due to safety reasons and the cost of a high-powered EDF, I would never trust cheap batteries.

Kirk