ARCC will convert owners’ existing Moultons, they had mine for 2/3 weeks. I chose to take and collect it from their (near) Cambridge base, worth it to speak with them and see the facilities. They also have an office in London near Finchley Road where you can leave and collect.
The current battery is a Bosch 4Ah, apparently good for up to 30 miles on a solo, but we get less than 20 on the tandem. We are awaiting the new Bosch 6Ah battery, due next month. We opted for the fast charger which takes only 30 minutes to fully recharge, and take this to use at tea stops rather than a spare battery, as it is lighter.
Sometime I’d like to try it with the bike in solo form to compare the range!