When you buy these packs you also have to buy the chargers to make it worth. http://www3.towerhobbies.com/cgi-bin...?&I=LXJC10&P=7 That's a cheap one for your transmitter, these are only 9.6 volts, and here's a really cheap charger that would charge them both http://www3.towerhobbies.com/cgi-bin...7&I=LXL331&P=K (I just ordered this) There's also a plug on the side of your remote where you can charge your battery without taking out of the controller. The total cost for upgrading to rechargeable batteries is around 80 dollars, including a "cheap" charger; whereas 12 alkaline batteries cost you about 8 dollars and they last you for about 20 to 30 minutes.