8 volt battery for the 6 volt DC CASE? Any discussion?

I plow snow with a DO on 6v. It'll crank over just fine, even at -20F. The key is more amps. I have a pair of 6V batteries that give me 1200 CCA. They are wired in parallel so that it stays 6V. The orchard tractors had the battery box relocated to the right of the steering column, I just added one on the left as well.

If 6 volts won't do it and you want reliability, install a 12 volt alternator system. The original systems were built to run all day long with a low charge rate maybe 3-8 amps. If you don't run your tractor for several hours per starting, you're not getting the battery charged up sufficiently whether it's a 6 or 8 volt battery. A 12 volt alternator works better for frequent starting with short run times. Immediately after starting, the alternator will begin recharging at a high rate maybe 30-40 amps. This provides a much quicker battery recovery than the old generator/regulator systems.
6 volt internal regulators are also available to install in 12 volt alternators. This will give the advantages of an alternator and still retain the 6 volt system.

You can install a rebuilt 12 volt Delco alternator for about $40-45, bulbs and battery not included.

K-Mo