11DCV too much for automotive 12 volt starter 10

[frankiee]

I have heard that 12VDC auto starter batteries put in cars are designed to operate at 9 to 10 volts and that if a person puts too much battery in the car, the starter can go and not be covered under warranty. He said that the company said that cranking voltage of 11 volts was too high and his warranty was void. He then put the smaller recomended battery back in and he did not have any broken starters after that.
Is there any body that could confirm that starter motors are designed around 9 to 10 volts DC

Thanks

 

[DieselGrease]

Keith: Your "fellow poster's" name must be Jake Cinnamon? Yeah I am going to change the wiring on that switch and make sure I have two batteries working "together" on 12vdc to crank that bad boy before I go and hit it with 24. I never had to put 24 on it before and don't want to have to resort to that unless necessary. I mentioned approaching "hurricane" in another posting only because where I live and the damage I sustained last year. If another comes I am moving the boat a bit inland for a couple of days.

 

[ccjersey]

You can make sure you have the switch right by switching to a certain battery, and lifting the ground connection of the other one and see what you have left at the indicator panel and to the starter. If lifting the ground kills the supply, either another bad connection or something still wired up wrong, or a bad battery.