Small Engines (Lawn Mowers, etc.): dead battery problem on an exmark, electric clutch, exmark

Question
I am having a problem with my battery going dead on my lazer z exmark. I can put a new battery on it and it only last a few mowings. What could be my problem? Thank you

Answer
It could be a problem with the regulator, or the alternator, or I have seen a Kohler charge poorly like that, all of the nagnets had come loose and stuck to the armature, and it still put out a little charge, but not enough to keep up with the electric clutch, but for more specifics, I will need your engine make and model number.

Thanks