From memory those Cyclematics have an unusual 95mm BB because of the controller box under the battery, so the axle is long, around 142mm. I used one from a scrap bike to fix my old Wisper 905, which was 90mm. I think there was 1 company in the US that sold them, but worked out to nearly £50, so was lucky otherwise the 905 would also have been unrepairable. If yours is still OK gazza, give it a regrease and make it last as long as poss.
Edit
Found 100mm sealed ones in the UK, if I'm correct about yours being 95mm, you would need 5mm of spacers to make it fit, poss on the non drive side to keep your chainline correct, although 2 +3mm would prob. work OK.
Only one left!