I have been charging overnight without a problem for a little more than two weeks with the 120v charger. For the past two days, however, the charger has been turning off after about an hour, with the car sounding multiple soft horn "bleats" and the top two lights on the charger going solid red. I will be making an appointment with the dealer, but I'm wondering what this indicates: the quick reference on the charger has info about the lower row of lights, but not the two upper being solid red.

Owners manual has the red lights, page 9-51

A ( Left ) is AC Voltage is out of spec, the B ( right ) charge cord fault and A and B is ground fault detected

Try a different Outlet/circuit , its possible you have lose plug or wiring causing a fault

I had that happened to me before, generally it was due to circuit overload, and the outlet was not able to drive enough current to the car. By switching the plug to a different outlet that is on a different circuit, such as the one from bathroom where they also have the benefit of GFI, my car rarely beeps except when my wife uses her blow dryer.

Thanks Henry_FL and tangentlin, that did the trick.

I was a little concerned because I had been using the same outlet all along with a heavy extension cord. The outlet was inside and near a basement window and it was working great, full charge every night. Looking a little closer, I saw the outlet box had another line coming out of it which ran to an external outlet, unused but definitely weathered. We had a ton of rain all at once last week, and it seems like that second outlet was the source of the fault. So I've got a home improvement chore for next weekend.

Used an external outlet (well covered and on it's own circuit) that was further away and all is well.

Update: The problem recurred, and I asked an electrician if my 12 gauge cord would suffice for about 75 feet for a device of the Voltec 120v charger. He said "Yes, it should, but for 100 ft I would go with 10 gauge". I re-measured and the distance was 100 ft, two 50 ft cords- not a 50 & a 25 as I'd thought. SO, now I am happily, solidly, completely charging using a 100 ft 10/3 cord, Rigid brand. About $140 at Home Depot. It will be awhile before I can go ahead with a 240v charger, so this is great

(I have several heavy duty extension cords for various equipment, so I lost track. This ten gauge one is brand new, for this purpose)