Still waiting for a refund but I contacted the seller again and asked if these bulbs could be run for hours at a time. I said that regular bulbs can be turned on and safely stay on for long periods of time.
This is their reply: "Thank you for your message it only work with 12 volt, what about yours? and could yu check connection the bad connection will cause burn". No point in continuing to even try to discuss it with them for the betterment of their products or service. It is what it is.
Yes my connection was the same wedge base that my incandescent bulb had been plugged into and left on for hours. The voltage was at 12.5 without the converter being on. No matter if in in RV or automotive use it's just normal to see voltages up to 14.2. Auto charging systems operate between 13.7 and 14.2 with some even going to 14.5. A bulb left on when connected to a running tow vehicle could see these voltages.
Moral of the story is along the lines of what some of you have mentioned, you can buy cheap ones and throw some in the trash and monitor closely so you dont have any fire issues. I do feel much more comfortable with the ones I bought at CW and they often see 15.3 volts.