Can a car battery have enough charge to turn the car electrics on but not start the car?

Yes, A car battery can have enough charge to turn on car electrical components but not start the car. This is not much of an indication of a bad battery however. Use a volt meter to test the power in the battery. If the battery seems low put it on a trickle charge. Most modern chargers will tell you if your battery is bad or not. The battery also has to be load tested to determine if it's good or not.