Husqvarna LTH18538 starting/battery issues..

[hmanv1]

Howdy, the mower I have has been giving me some issues this spring. The only way I can start it is to use a car battery, and even then it struggles to start at first. After I get it running, it's amazing, but the starting has been puzzling. Whenever I use a normal tractor battery, it turns over very slowly and then the battery voltage goes down to 6 volts and then continues to dive and then the tractor won't even turn over, no sounds, nothing. Even the car battery dives in voltage, but it has enough to get it to turn over and start. What the heck is going on to where it causes my tractor battery to crash?
After I disconnect the tractor battery, the voltage slowly climbs back to normal and it appears to be a good battery. I have two other decent tractor batteries and it happens to all of them when I try. The only thing that will fire it up is a car battery. Think I have an electrical issue or starter or what?

 

[NorthBama]

what is the engine make and engine number

 

[mikebarber]

If it was mine I would replace the starter then open it up to confirm your problem after you have removed the starter hold it to your nose and you will probably smell the burnt motor scent that should confirm for you you probably have windings that are burned and shorted now I am assuming that you have removed all connections cleaned them with emery cloth or a small wirebrush I have seen this very issue several times I buy my replacement starters and alternators from "DB Electrical" If you don't use paypal they do not charge tax my mastercard works great