Yea 6 volt syatems are wack. Once you get some high resistance in the wiring the voltage drop will cause issue after issue after issue. But yes electricity is fun, lol I get to into it

 

Odyssey if you got the coin...but it all depends on how much power you need, too. Running a winch and high-powered lights (not LEDs)? Big sound system? etc... I have a little Interstate Mega-Tron in my daily driver Mazda, going on 3 years in PA winters and never had a problem. My jeep has a "battery warehouse" 500CCA battery, and it looks like a hunk of junk to me but it works OK. I'll be replacing it with something much nicer when the time comes.

 

Depends on engine sizing & compression, mainly.

No-load current for the 6-242 starter motor is about 170A +/-10A. Typical starting current (engine load only, ~9:1CR, six cylinders, 242 ci displacement) runs about 200A +/-20.

Diesels have phenomenal cranking motors because they're such high compression (most Diesels have two batteries, but they're still 12V systems. The batteries are connected in parallel - voltage is constant, current is additive.) A light Diesel can need >350A to crank. The big industrial jobs? 1,000A isn't uncommon, and is somewhat low.

You don't really need an ammeter to check your starter loading, tho - check your battery voltage at rest (should be >12.6VDC,) and keep the meter on the battery while you're cranking. Cranking voltage shouldn't drop below 9.6VDC - if it does, investigate further (clean terminals, make sure your starter motor is properly mounted, hydrometer test on cells, if you are able, ...)

 

Okay, your load ratings are about right. We were testing the starter on my 67 Camaro 350 with 10.5:1 compression at the time. It was drawing 250 amps. My friend's Pontiac is not only 6 volt, it's also a direct drive starter, not geared down like most today.

 

ANY brand is a crapshoot. There are only 2 major battery manufactures. The most dominant is Johnson Controls. When you buy a walmart battery (or most any brand) it could be made by either manufacturer and there is no way of telling. Walmart switches back and forth at contract time and when demand is high they will buy from both.

 

I'll bet there is a manufacturer code somewhere on the case of the battery. like a DOT number on tires. Finding it and deciphering to would be like reading the code on a soup can.