Hi Scotty and crew!

I've got a 2017 Toyota Highlander XLE with the 3.5L engine.  I purchased it new in Spring 2017.  This was the first year they used stop/start in this model so it has an EFB battery.  It still has the factory battery (GS YUASA enhanced flooded cell battery) and I've not noticed any degradation.  The car starts up just fine and the stop/start nonsense works.  About 1.5 years ago a Toyota dealer service department told me I had a Walmart battery and that it needed to be replaced for the fantastically low price of $600.  I walked out with the advisor, showed him the battery, and asked since when did Walmart start selling GS YUASA japanese imported batteries..  I started taking it to a different dealer after that.

Fast forward to present day at my most recent service visit (with the different dealer) they said it failed the load test and recommended replacement for $400.  I couldn't help but notice the tech that was working on my car was the same guy that said I needed new engine air and cabin air filters even though I had just replaced them myself with OEM 5,000 miles earlier.  I declined and took it to Autozone on the way home for a second opinion.  They tested it at 12.67 volts, but the tester said "bad battery."  The store rep said that the battery is in great shape and that it only said "bad battery" because his tester isn't setup for EFB or AGM batteries.

So my question is if the car is starting just fine even in freezing Colorado temps are the dealers just being greedy or do I really need a new battery soon?  If I do I'm just going to buy an AGM battery from an auto parts store.