Hi Gary, I too had the "Check Charging System" light and chime go on last Monday. I held off posting on the forum and was waiting to see if anyone else had this issue besides me. I was going about 40 mph when it went off and didn't notice a loss of power, but then again I just pulled over to the side of the road and shut the car off and re-started it and all has been fine since. I just had the car in about 2 weeks ago to have the recalled sensor and headliner replaced, and the car has driven the same as before the repair was made. What I did notice at the time the warning light went on was that the battery meter was just around half, which is where it normally is most of the time. I was going to call the dealer the next morning, but decided to drive it more and see if it would do it again, but it hasn't and I have been driving it daily. I hooked it up to my diagnostic reader and there is no code in the history to bring to the dealer. If it does illuminate again, I will bring it back to the dealer. In your case, since it has happened 4 times in 2 days, I would definately get it checked out. Hopefully this is not the next phase of issues that we will be dealing with as I expect some bumps in the road since this is the first hybrid that Hyundai has produced. I truly enjoy the handling, mileage, quietness, and feel of the vehicle as a whole, but can't help but wonder if some are wiser to wait for the 2012 models to hit the market which will hopefully have all the quirks dealt with. It's my 4th Hyundai and I have been quite happy with the company thus far, and have faith that they will do what's right by us.
Good luck, Vinny.