Not all battery packs of a given type are created equal. For example, not all 85 packs have been capped on voltage or charging speeds, and there are 3 versions of the 90 packs. In researching used cars, it's best to see what the rated range is for a given charge level and extrapolate full based on that number. If the seller will allow, you can attach an OBD2 cable to the diagnostic port and then running a bluetooth OBD2 module w/a CAN bus scanner to determine voltage and other details of the battery such as how much level 3 charging it has done and what the voltages are.