We were not that concerned with the accuracy as we were with making sure they were at least 80 pounds or more going into winter (pref. over 100) and they did not drop below about 35-40 in the spring to avoid them starving out. It doesn't surprise me you get different readings depending on the side - I would think the side with the most sun would be the heaviest, but I never actually checked them that way (and this was before all the problems with colony collapse we are seeing these days).