Load test a bank of 6 AGM house batteries.

For the last 10 plus years load testers have been obsolete. That said a carbon pile can exert a load against an alternator to test it's capability. Now days they use a battery, starter, alternator diagnostic tester. They are powered by a 9 volt battery and merely send impulses into the battery and analyze the condition of plates. In seconds you get messages such as Good battery. Bad battery , Good battery needs charge needs charge . The sheer beauty of these testers is they take absolutely nothing out of the battery and no days of charging required such as after a load test from years ago. People selling and warrantying batteries are required to have these type of testers for obvious reasons . Can you tell I used to sell both carbon pile testers in the old days and the modern ones in latter years and own one of each. The modern ones are also small enough anyone could carry one with them . My units incidentally are Snap On