Wish it were that simple..this tractor has ecus just like a car plus many...many electrical devices on it eg shuttle valves..electric spool valves..solonoids etc etc plus ac...dozen lights and so on. On some days it will be stopped and started dozens of times ...much more thsn a car ...and the engine is over 6 litres with huge loading on the starter.
I had Optima in our D1 and D2 and replaced them with much cheaper old school batteries. I never missed the costly Optimas. We did compitions too involving heaps of heavy winching and never had a failure.
BTW I mentioned lithium bats to the store owner and was pleased with his frank analysis which largely amounted to ..they are just not there yet in terms of pricing and reliability. They are for the future no doubt.

