We just received our two new Rad mini step-throughs. Assembled last night and tried to remove the battery to charge it. We followed the instructions, using the key in the unlock position. It feels like it’s disengaging the slide bolt, but we can’t get the darn thing off! In struggling to get it off we discovered it came charged, but some day I’ll need to remove it. Haven’t assembled the second bike yet, so not sure if this is user error of a locking mechanism issue?