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My dad has an older airplane that he use to fly and the battery pack for the transmitter does not work and i dont know where to find one its a 10.8 volt 500mah 9 cell pack does anybody know where i can get one or something that will work in its place any help or info will be appreciated
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The only radio that I know of using 9 cells that is legal today would be a World Engines Expert. If an older Kraft, it isn't legal unless updated to the requirements of *Gold Sticker* some 10 to 13 years ago.
You can get some fine small Chargers at Radio Shack ($8 to 14) with variable plugs -- one will fit -- that you can charge the transmitter pack with. Might as well get one capable of 12 volts to ensure full charge, and at least 250 ma output. Make your own with tab cells and use a minimum of 600 ma and preferably 800 ma.
I have one small "Adapter' that I found at Walmart with multi plugs and selective polarity for the plugs. I tapped in another wire with a 2 pin plug in. It is 300ma. with selective voltage from 1.5 to 12V. It makes a fine field charger for either JR or Hitec Tmttrs. plus an airplane. Sooo expensive at $6.95.

Today's batteries have no problem for quick recharges at up to the batts' rated ma.