2017 Jeep Grand Cherokee Limited. Had an issue with the auto start/stop the other day. The vehicle shut off at a stoplight like normal, released the brake and the vehicle shut off completely and threw it in neutral. Had to completely turn it off and restart it. No other issues besides the function not working. No issues the following 3 days either. Fast forward to the 4th day, go outside to start it that morning and no power but starts right up with no issues. I left it running for a while and noticed the voltage was running at around 14.7 telling me that the battery is charging, however, was still showing 14.7ish about an hour and a half later, still running. Next step was to get a battery, got the new one installed but didn't buy a new auxiliary battery thinking it was the main one that was the issue due to having no power. Everything is hooked up properly, yet no ignition power, but the interior and dash lights turn on. After trying a few different things all of the lights started to flash and multiple error lights came up on the dash (liftgate malfunction, power steering failure, and the gear selector lights were flashing). Checked all connections and nothing worked. Do I need to buy the auxiliary battery too or do I have a bigger issue with it? Also, the battery I replaced is the factory battery from 2017 as well as the auxiliary battery but again that hasn't been replaced. Any comments or help is greatly appreciated.