We use an old chest freezer. Put a Johnson control on it to turn it into a cooler. Where we pig hunt we can just plug it in. Then pack it with ice for the drive home. About 11 hrs.When we get home we plug it back in until we can process. If you put the word out you can get one free or cheap and the control is about $50
Could you explain the "Johnson control" feature? Are you talking about a generator?
