Zoomy
Established Member
Posting here thanks to Ed Wood on the Facebook group
The response from MG, who are not known to disclose things directly to customers, was to EO and highlights something many of us have known for some time about how they’ve gone about timed charging and likely a hardware limitation on the car complicating matters
“Your customers are seeing this issue because our car cannot be woken just by a change of duty on the CP PWM signal.
In the example below the customer is connecting the vehicle and your charger is advertising 100% duty on the CP. If there is no change in this duty (to a level that would allow charging) within 10 minutes of connection, the vehicle will sleep. The change to a 53% duty cycle will not wake the vehicle.
Our vehicle will only wake if the CP line is transitioned to 0V or -12V for greater than 3 seconds and then back to +12v
We do understand that this doesn’t fully meet the BS/IEC 61851 standard and we are working on an update to solve this. Unfortunately, because of our vehicle hardware, this isn’t a simple fix for us so we currently have no timescale of when it would be available.
Some smart charger manufacturers have been able to modify their software to add a transition to 0v or -12V for >3 seconds before the scheduled charging starts
Others have opted to set a low charge current (10% PWM) so the car charges very slowly and then increase to 53% at the time scheduled by the customer. This obviously isn’t ideal as the customer is paying more than they would for a ‘genuine’ scheduled charge.
I hope this explains the issue to you and if you need to perform any testing on software changes then please let me know and we will try our best to support.
Thanks for your understanding”
The response from MG, who are not known to disclose things directly to customers, was to EO and highlights something many of us have known for some time about how they’ve gone about timed charging and likely a hardware limitation on the car complicating matters
“Your customers are seeing this issue because our car cannot be woken just by a change of duty on the CP PWM signal.
In the example below the customer is connecting the vehicle and your charger is advertising 100% duty on the CP. If there is no change in this duty (to a level that would allow charging) within 10 minutes of connection, the vehicle will sleep. The change to a 53% duty cycle will not wake the vehicle.
Our vehicle will only wake if the CP line is transitioned to 0V or -12V for greater than 3 seconds and then back to +12v
We do understand that this doesn’t fully meet the BS/IEC 61851 standard and we are working on an update to solve this. Unfortunately, because of our vehicle hardware, this isn’t a simple fix for us so we currently have no timescale of when it would be available.
Some smart charger manufacturers have been able to modify their software to add a transition to 0v or -12V for >3 seconds before the scheduled charging starts
Others have opted to set a low charge current (10% PWM) so the car charges very slowly and then increase to 53% at the time scheduled by the customer. This obviously isn’t ideal as the customer is paying more than they would for a ‘genuine’ scheduled charge.
I hope this explains the issue to you and if you need to perform any testing on software changes then please let me know and we will try our best to support.
Thanks for your understanding”
