Bobbo wrote:
As long as the battery is sufficiently charged during that 2% of the time that your converter/charger is not working, no problem. If the battery is NOT sufficiently charged, or runs down, the fridge will stop cooling. However, as long as the fridge door stays closed, it will stay cold for hours, so, no problem. If it stops cooling, and stays off long enough for the fridge to get warm, you will have to throw out spoiled food.
Even your old gas/electric fridge needed 12v power to run. It must have 12v to power its electronics even when running on gas. So, it was no different.
If you think you might go too long without charging battery, put few ice cubes in cup in freezer. Once all recharged, and has run to cycle off, look at cubes. If it has got warm enough for food to be unsafe, the cubes will turn into puddle