Update, I have bought a s/h non-electric Brompton (technically second hand but it was unused), and in most* respects (*caveats later) I'm glad I did because it's taught me a worthwhile lesson. In my opinion my riding competence isn't yet good enough to handle a smaller wheeled electric bike; as it stands I'm sure I'd be dangerous. The initial only (I hope) lack of confidence/competence is a good thing for self preservation. Even after a few rides I'm definitely improving, but muscles and stamina have a long way to go so it was the right decision - for me at this time - a long time no rider. It folds and stores beautifully.
My plan is (or was) to eventually electrify but this comes with some comments.
Electrifying a Brompton to what would be an acceptable standard where it retains the fold and luggage convenience isn't that easy and is thus expensive.
The current 2022
Swytch kit is an attractive proposition at first glance, but not well thought out for Bromptons because the standard kit has to either have the battery holder facing the rider (it won't fold if it's on the outside of the handlebars, their advertising is/was misleading) OR (by paying extra£) it can use the luggage holder, but that prevents using a luggage bag on the front. Both of those are less than ideal.
The
Nano and
Onemotor (as alternative examples, there are others) are better in that respect BUT for what you pay for those conversions plus a decent second hand Brompton you may as well have bought a proper electric Brompton in the first place (that is if you could afford it). The Onemotor is (allegedly) very easy to move to different bikes if you have more than one bike it's a good option. (but that's not relevant in my case.)
So that brings me to a question, if it cost much more to electrify your current bike (EU 250W compliant) with a conversion kit than what you'd pay for a reasonable electric folder (again EU 250W compliant) what would you do?
You can buy a half decent 20" wheeled electric folder for a
lot less than the well over £1000+ ($1200+) it would cost to convert.
*The biggest issue that I never anticipated on the Brompton is the placement of the brake levers to have them where I would be most comfortable but placement is more limited than I would like because the fold restricts how far they can be moved upwards. I didn't know that (or didn't give it enough thought) when I bought it, but that's perhaps a discussion for another time and place and anyway I'm stuck with it and hopefully It will become less of an issue as time progresses. It's maybe not an issue for most but more for those who may have restricted finger movement.
Secondly it doesn't handle as stably as bigger wheeled bike, but that's academic because I had no suitable space to store a large wheel electric bike.