After remote start it wont stay running

First of all, it is extremely dangerous to disconnect a battery cable when the engine is running. I can post a copy of my standard reply if you want me to, but to sum it up, it is real easy to destroy many of the computers on the vehicle when the engine is running on just the alternator.

The no-start is related to disconnecting the battery. The Engine Computer lost its memory and has to relearn "minimum throttle" before it will know when it has to be in control of idle speed. Until that is done, the engine may not start unless you hold the accelerator pedal down 1/4", you won't get the nice idle flare-up to 1500 rpm at start-up, and it will tend to stall at stop signs.

To meet the conditions for the relearn to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the pedals.