I just wrote an article on Ebike batteries. Every bike maker and model seems to have a different battery. I placed in that article a Chinese company that seems to make the batteries for every Ebike. The bike companies just stick their name on it or resell it.
It seems (not an expert) that these bikes are basically made of "off the shelf" parts. No one wants to make cranks, brakes, handlebars. I see a similar bike frames on different makes of Ebikes or have very slightly different style. The virus has done shipping and storage of parts impossible for many companies. I saw one name brand Ebike with customers waiting over a year (2021) trying to get a battery for that specific model. I believe that problem is finally getting resolved.
I bought a Magnum i6 at a nearby NJ store. It closed a year later but a sister store more then an hour away in a larger town is still open. My 3 year old bike only has under 400 miles on it. So battery and all parts still are working fine.
Can't say what bike is better, but check out the battery. The Ebike REVI Predator, Aventon Pace 500, Addmotor M550 – P7 and M5600 mid drive, Surface 604 and maybe a few more makes take the same battery. Prices vary, but it seems to be a replaceable item you can find. There are other makes of Ebikes that take different batteries. Just watch out for those $600 Ebikes. The reviews are usually not good. Many with the battery only lasting a year.
