testing each battery separately?

[mwilk012]

Mistakenly, I think.

The Jeep is running like a champ with it's two new warrantied batteries and it's original "faulty" (according to Autozone) voltage regulator.

You Autozone detractors may have been right all along.

With today’s smart charging systems, a simple voltage check is just not enough to say definitively that an alternator has failed. The voltage regulator is built into the alternator, by the way.

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[JJJEEEEEEPPP]

I replaced my AUX battery about a month ago as the jeep was having issues. But then after about a month, Jeep again drains out on the battery and I have to jump start it if its sitting idle for 3days or more.
Got my Main battery tested in 2 ways:
1) Autozone : Disconnected all terminals from the main battery to isolate it completely. The Autozone guy said battery has no voltage and needs to be charged for at least 2hrs before he can test it. He also said it may be a bad alternator. But could not confirm until the battery is charged.
2) Oreily : I then went to Oreily and asked them to test with all the terminals connected to main battery. The tester showed bad battery.

Now I am not sure if the test at Oreily was valid or not as my main battery was still connected to the AUX. If the test is valid, then which of the two batteries is bad?

After reading this thread, I am planning to do another test with only the negative terminal disconnected.