We had several similar problems when the car was new. Nobody ever explained the reason. The tow truck driver had many similar experiences. The problem is that the Ionic charging system only charges the main batteries, not the separate 12V starting battery. He boosted the car and the false indication that the regenerative brake system was faulty disappeared. The car runs fine.

The problem stems from taking several short distance trips. That drains the starter battery and the engine does not get enough time to recharge it. How they could design a car with such a basic shortcoming belies reality.

Now that I know what the problem is, I'll install a separate trickle charger that can top up the started battery when we plug the car in overnight. I'll also carry a small booster pack in case I get stuck again. Thanks to watching the tow truck operator, I know exactly where to attach the booster cables.

The car has always been serviced and maintained by our Hyundai dealer. They indicated that after the car was towed to their lot, they would not be able to work on it till next week (it's Friday today). Am I wrong to suspect that this fix is not included in any documentation because they make more profit by servicing the car at the dealership?