Use the battery shields that come with your SkyScout. These are essential for accurate usage of the SkyScout.
The SkyScout needs a minimum of 2.4 volts from its batteries for normal operation. The nominal 3 volts delivered by a pair of over-the-counter AA batteries is ideal. Some rechargeable batteries may not have enough voltage even when fully charged.
The battery indicator on the SkyScout will show a full charge, then suddenly drop to a lower reading and stay at the lower reading until the batteries lose chage after hours of use. This is normal operation.
Usage time will vary widely. To maximize battery life, avoid using the audio and keep the backlight low.
When turned off, certain circuits in the SkyScout draw power at a very low level that won't really drain or affect overall battery life.
Have you tried different batteries? Not all batteries are created equal. Even batteries from the same manufacturer can have substantial differences as far as their magnetic fields are concerned. Once in a while there are batteries that can affect the SkyScout's magnetic field sensors even with the shields on, preventing it from proper function. Steel-cased batteries can be inherently magnetized and should be avoided. Nickel cadmium types are not recommended. Nickel-metal-hydride batteries work well.