^^ Not to be a negative Nelly, but based on literally every encounter I have had with AZ with regard to battery and/or alternator diagnosis, I would strongly suggest you get another opinion (from a reputable professional).
A local shop who I trust (Service One Auto fka Kwik Car) tested and said itÂ’s just the battery. Alternator fine for now but could die if I ran too long on the bad battery. They are Installing a new battery now for less than $200.
FYI AC Delco OEM battery is 20% off on Amazon right now bringing it to appx $170 shipped plus tax.
Good info here on this forum which I appreciate.
And then there's also this...
https://www.chevrolet.com/certified-service/car-battery-coupons
BATTERY OFFERS
Battery Offers
More power to save
Keep your vehicle powered up with an ACDelco*battery*from the Chevrolet Certified Service experts. And save with these current battery offers near you.*
*Visit the*Certified Service Rebate Center*to download or submit your rebate form and/or check the status of your rebate.
$20 Mail-in*Rebateâ€
on the purchase and installation of an ACDelco Advantage or Professional battery when purchased with a GM or BuyPower*Card®️â€
OR
$10 Mail-in*Rebate†*with any other form of payment
Offer Ends: 8/31/18
No-Charge Battery Test Good on Most GM*Vehiclesâ€
Visit your local dealership to have a Certified Service expert test your battery for free
$114.95†*or less*on most ACDelco Advantage Batteries
Installation extra: $24.95 or less on most Chevy*vehiclesâ€
18-month*free-replacement limited*warrantyâ€
$144.95†*or less*on most ACDelco Professional Silver Batteries
Installation extra: $24.95 or less on most Chevy*vehicles.â€
30-month*free-replacement limited*warrantyâ€
$159.95†*or less*on most ACDelco Professional Gold Batteries
Installation extra: $24.95 or less on most Chevy*vehicles.â€
42-month*free-replacement limited*warranty†**
Battery Offers End: 12/31/18
Locate Participating Dealers
Learn About Batteries
Print All Offers
View All Offers
Testing your battery
Bring your vehicle to the Certified Service experts and they’ll test your battery to ensure all systems are working properly. If your battery needs replacing, the Service experts can help you find the right battery for your vehicle.
Hope this helps.