I dream of a car with barely any electrics at all — so much so that I have a recurring brainworm about other ways of starting the engine than electric.
I use a riding lawn tractor(mower) to start and run my flathead powered vehicles/Tractor Supply sells me one for less than $50 and they usually last 4-5 years with continual use. When going thru Harley Davidson mechanic school in 95/96 in Phoenix,Az. the instructor told the students that batteries have a “memory.” The first time a load is applied to the battery is where it will return to after a normal days use and “cool down” the next morning. I always charge a new battery(for a short time—maybe an hour) to give it a higher memory voltage than “off the shelf” voltage. Many will say a Flathead is a weak engine, but I often have as high as 150+ lbs of compression in my engines. Nothing is more out of place to raise the hood of a nice hot rod a see a big,honking ugly *** battery that looks out of place. My engines spin over like a Chevy v8 with the plugs removed.
Right, there’s a couple things going on. Brand new batteries are “hard” and will not accept or p*** their rated current output until a dozen or so engine starts. But the engine alternator isn’t going to fully charge it either, not in typical use. Of course it will start the engine, which is more than “good enough” for most. If you look at the charge tables for sealed “maintenance free” or some of the modern batteries they have a bit higher open circuit voltage than the 12.6 volts all the textbooks used to cite. It isn’t a “higher” memory voltage we’re looking at, many batteries probably never reach their advertised voltage and capacity when placed into service. This is where those old school “dumb” taper chargers are really good, an hour isn’t nearly long enough, let the new battery charge at a low rate at least overnight, during/after it has a few engine starts under its belt. Should see the more modern battery rest at 12.80 volts, after the surface charge is removed. 12.65 volts is a spec for standard lead-acid batteries (with filler caps to add water) at 77° F., 0.2 volts difference is a lot on a percentage basis, and maybe not quite 20%. 10+ years service life out of just about any battery should be routine, at least up north, without necessarily making a hobby out of it. Maximum service life is nice, but proper maintenance will also save a lot of wear and tear on the charging and electrical system and you’ll get maximum performance when required. Ratty cables and corroded grounds will cripple any alternator no matter how big, too.
The Jalopy Journal
