Due to circumstances I happen to see the result of a lot of AAA service calls. They'll send out a "battery tech" who hooks up a diagnostic tester to the charging system.
It seems they're constantly telling people their battery and charging systems are "good" and jump them only to have the car die a few miles down the road and elsewhere be shown to have a bad alternator, or tell them to "run it for 30 minutes and you'll be fine" after a jump only to have it not start again and be told elsewhere the battery is bad. Or sell them a ridiculously overpriced battery and have the car die on them and find out elsewhere the problem was their alternator.
I get the sense that for the most part the extent of their tech training is being taught which buttons to stab in what order on the testing box.
Anyone have familiarity with the specifics of how they do their testing and why the results seem to be pretty much useless?