Grab and go batteries for what exactly? Lead acid batteries for gasoline powered motorcycles or batteries meant for electric scooters and mopeds?

For starters when I saw modular batteries I mean batteries in which you can swap out individual cells as the original post suggests, not whole batteries you can swap in and out of a vehicle. Secondly though car makers could standardise batteries between them this would severely limit them in many ways. We like to think of batteries as the equivalent of a gas tank in an internal combustion car but that's not exactly the case. Yes batteries store an amount of power inside but the role of the fuel pump is also up to the battery, that is the rate at which it can charge or discharge has to do with the battery. Moreover the weight and shape of the battery changes from manufacturer to manufacturer and in many cases the battery housing serves as a structural member. This means that not only the capacity and therefore range are determined by the battery but also the charging times, power output, vehicle handling and weight distribution and chassis construction. So if you limited manufacturers on using a specific set of batteries, they'd all basically have to make the same cars, just with different looks. Two cars using the same battery but different electric motors would still have the same maximum power output at the wheels which is limited by the battery, a stronger motor wouldn't be able to draw power at a faster rate to output more power to the wheels.