Yeah, I know, I'm not arguing against electric now, or even as a concept then. This was an alt-history exercise, remember?

Batteries could have been standard for a bit longer, but it seems to me that eventually the need to go faster for longer would have forced combustion engines to be a thing. All they had were lead-acid batteries (or primary cells, but that would be dumb) and new more energy-dense chemistries didn’t show up for a long time after. Maybe they could have found one if they really needed, but it’s a tricky science even today, so I’m skeptical.

It’s possible, I suppose, that infrastructure could have been rolled out for both en mass, but I don’t see an even mix lasting through the whole 20th century. Probably not even past WWII.