Quote Originally Posted by jaxsprat View Post
I have used a car battery in pinch years ago, but Yes you can get a voltage spike from them when your motor is running. With these new electronics I would NOT ever try it again as all you need is one spike & u going to be need a new fish finder, cause you gonna fry it crispier than a crappie.............................
No! You can't get a voltage spike from a battery! Each car battery only has six cells in total they produce 12.5 volts. ONLY 12.5 volts. They can not produce any more. That is basic electricity. And how do I know? Well, I am a ASE certified master auto technician and have been for 18 yrs.
If you think that a battery can produce voltage beyond 12.5 volts feel free to explain your "theory."
You can have a spike of amperage however. It happens often when a motor is started. But that is not related to the battery at all. You can connect a amp meter to a trolling motor and turn it on. You may often see a spike in amperage then a sudden drop to what is the normal running voltage. There is no difference in a car battery than a deep cycling battery other than a deep cycling battery is built for constant discharge and recharge.
They have no internal regulator!