I have done some further investigations and the 2014 onboard charging works as follows:
When the onboard charger is plugged in and powered on the onboard charger pushes:
- 5v and 48mA through the Charger attached pin #11
- 5v and 26mA through the Charger enabled pin #12
The 5v ground reference is Pin #13 which is battery negative
With this knowledge I'm able to use the onboard charger connector to add my own onboard charger solution which functions as follows:
1. Run a separate circuit that when triggered pushes 5v ~50mA through pin#11 (attached charger) with the other end of the 5v circuit connected to the battery negative pin #13.
2. When this is triggered the bike shows the battery state of charge % and charge time remaining, closes the contactor and allows charging - through the fast charge port, the onboard charger port or via the Sevcon battery terminals for high power charging.
3. Upon completion of charging, the 5V can be switched off and the charge level and time remaining switch off and the contactor opens just as with the onboard charger.
4. The bike can be keyed on and ridden away as normal.
Using this method there is no need to leave the bike on when fast charging via the Sevcon cables or if you are using the fast charge port without triggering the auxiliary pin on the fact charge Anderson SBS75X.
Hope this is helpful for 2014 owners who may not have an onboard charger and want to add their own additional charger/s without limitations of the fast charger port (100A fuse and need to physically connect/disconnect chargers when charging/riding respectively).
I believe the 2015 onboard chargers use CAN signals so not sure the same approach can be used.