You do not really need a battery load tester. Either the battery will hold a charge or not. Either the alternator is charging or not. That my friend is what the volt meter is for. Electrical and electronics have paid the bills since 1966.
well, at $30 it seemed like it was worth having - automotive electronics was never my thing - although I was an industrial electrician for several years a very long time ago, but there is a big difference between setting transformers and pulling wire than what goes on in a vehicles charging system. Oh and I will add that having that little meter gave me the information I needed to feel comfortable replacing my last slingshot battery before it actually stopped working - first time in my life I actually didnt have to deal with being stuck someplace with vehicle that wouldn't start - - yea I probably could have gotten a few 100 more miles out of it, but thats okay I would rather avoid getting stuck.