Cast Iron electrolysis using a 12V Boat Battery?

[hotpan_]

I'm tackling a huge pile of rusted cast iron griddles from the summer camp! I want to use electrolysis, but I don't have a battery charger, just a 12V boat battery.
Can I safely use the boat battery as my power source? Will it put out the right kind of juice for rust removal?
is this safe? cause I don't want to accidentally electrocute myself or ruin the griddles! this is my first time!

 

[mimic ^^]

You will need to add a resistor or regulator to keep the current low. And use a manual or automatic charger because it gives a consistent flow and is easier to monitor.