Hi Dominic, I should have explained better, yes it’s the charge plug pins behind the seat, you should be seeing over 60v there, and on each individual battery you should be seeing over 12v, from memory mine is between 12.5 and around 12.8 per battery.
Looking at your terrain map, and given that you are carrying 25kg more than me, Imwould say your mileage isn’t far out if you made the 17.5 mile trip with over 600ft of elevation thrown in.
Regarding the re-gen braking, have you noticed when you touch either brake enough to activate the brake light switch you also hear a light ‘growl’ from the motor, and feel the bike slowing? mine certainly does although the manufacturer claimed it didn’t have re-gen braking, but mine certainly does, as you can feel and hear it, I actually disconnected the rear brake light switch for a while as the re-gen was causing the bike to lurch/shunt at low speeds when braking, as it clicks in and out, so by disconnecting the rear brake light switch I could use the rear brake for the last few yards when stopping and avoid bringing the re-gen into play and the lurching/shunting.
Re-gen braking works by turning the drive motor into a generator when slowing down, hence it converts braking energy which would usually be wasted as heat, into a bit of electricity back into the battery, and resistance from the generation gives some braking effect to, so it’s a win win situation, most electric vehicles have had it for years.