But, but, the other terminal on those batteries is floating?

As an earthling, you have evolved over the course of billions of years to deal with sunlight at a distance of one astronomical unit. That’s the distance of the earth’s orbit. That’s probably the most comfortable distance.

The Apollo moon missions used a so-called “barbecue” mode that rotated the capsules at three revolutions per hour. They did this during the 3-4 day coast phases to and from the moon. As far as I know this was able to mostly hold the interior temperatures in the “survivable” range.