I flew for about a month or so and I seen the red indicator light flash on and off si I changed batteries next day. At the time I was using stock battery in heli and was doing two to three flights a day. Batteries I used are Energizer I believe. I just got the least expensive high performance alkaline. Transmitter still going strong but I do check for red light each time I turn it on. I do not want to crash because of TX batteries going low!