On my 2018 Rover, I place my hand behind the battery, between it and the down tube using it for leverage, and it comes loose from the connecter and just slides right off. It should not be that tight on the rails. You may want to check the locking post on the bottom of the battery and make sure the 2 screws are tight. I've read others having that issue and the loose screws allowed the "unlocked" bolt to drop down just enough to hang it up.