The reason I originally asked this question/mused this future development is because I've been doing some longer trips on my e-bike whereby I need to use the power sparingly to get the range I desire, or plan accomodation where I can charge overnight.
I have a BBSHD with a 17.5Ah battery and a 2A charger. It'll do 50 miles fairly comfortably using a nice amount of power.
For one example, I cycled to Bath along the Kennet & Avon canal, this was 50 miles and I got the train back and then had enough power to cycle from the train station back home. I subsequently observed I could probably have found a 3-pin plug on the train and added 2-3Ah during the return journey, but no guarantees. I'd have happily locked the bike up for a couple of hours in Bath and recharged such that I could cycle full journey home.
For another example, I cycled from home to the Isle of Wight (~45 miles), recharged overnight in a Travelodge, then did a full lap (85 miles) of the Island, then recharged overnight again in the Travelodge, then cycled home again. I'd have rather camped but there would've been no charging available then. On the 85 mile day, I was really pushing it on range and so was using minimal power. I'd have been much happier if I could've fast charged 8Ah or so over lunch or a cake break. I did observe there were some 3 pin plugs available on the 1 hour ferry crossing.
I know I can buy a 10A charger, although possibly my battery (an EM3EV) wasn't really designed to be charged at that rate. I went in a few Cafes and possibly I could've asked them if it was ok to charge for a bit, but there's no guarantees they'd be happy with that.
....so that's what got me thinking. There's now a pretty amazing network of public fast chargers for cars. Cars and mobile phones can do something like 50% charge in 30 mins. It'd be great if an e-bike battery was developed that could fast charge and use the network of public car chargers.
There are some obvious physical constraints, like the charge connector that cars use is huge!
I'd not realised that Zap map also listed 3-pin plugs. That could be useful and a step in the right direction!
p.s. I'm not sure this is available even for motorbikes yet... A colleague of mine got a parking ticket for charging his electric motorbike in an 'electric cars only' parking space.