[rattlsnak]

Test light does not work properly as there is resistance in the bulb and it creates a current draw. Only true correct way is to use an Amp meter. Acceptable draw is less than 1/4 of the reserve capacity of the battery. (should be written on the battery somewhere on the label. Most are around 100, so you're looking for a draw over 25ma) If the draw is less than that and it still goes dead, then the battery is failing.