Understanding smart / dumb charging

[tsedge]

Hi,

Just want to clarify whether I have got this right and maybe help others new to home charging.

1. Rapid (>22kW) CCS chargers know the car’s state of charge because that is part of the CCS protocol, which is why you can see the car’s charge percentage on the charger.

2. Fast (7-22kW) Type 2 chargers don’t know the state of charge, because it isn’t part of the protocol, which is why manufacturers create APIs that can be used to interrogate the car and charge it in a “smart” way. To fully integrate with variable cheap rate electricity, the electricity provider has to support the charger and/or car - eg like Intelligent Octopus

3. Dumb charging is still perfectly possible without a supported API because the level to charge to can be set in the car itself, does not have to be controlled by the charger. Octopus Go can be used like this.

4. People have mixed experiences with the supported vehicles/chargers for smart charging due to problems with APIs changing.

Please let me know if I have got this right and if not, what I have gotten wrong.

Many thanks,


Tom.

 

[MundaneMatt]

CCS chargers charge at DC, which goes directly into the battery which is DC. And receives the BMS percentage directly from the battery.

Type 2 AC chargers connect to the converter/on board charger which converts the AC charge to DC and sends it to the battery.

You can charge your car on a dumb charger, people just like to play around with the power rating their vehicle gets due to PV solar and tariffs.

The biggest issue with APIs is that car manufacturers try to make their cars smarter, but make them more incompatible with charge points. Volkswagen Audi Group are having a massive issue with a number of different charge point manufacturers at the minute because of this.

 

[tsedge]

Thanks Matt

 

[BugEyed]

1. Yes
2. Sort of. Public APIs are where manufacturers allow 3rd parties to access (some) information regarding the car, in this case the SoC. Some vehicles (like the original ZS) have no communication between the vehicle and a central server, others do but the manufacturer (SAIC) choose not to provide 3rd party access to the data. However this data is only required to charge to a target %, Intelligent Octopus can be set to provide a given amount of charge (in terms of additional % of the battery) regardless of what level that will result in. That's how I use it with both the previous MG5 and my new MG4.
3. Dumb charging is when the charger and the car start charging when plugged in. As you say, some cars and some charge points can set timers which the Government counts as "smart". Even better some cars such as the MG4 allow you to set charge limits.
4. There's a variety of issues with delayed and smart charging. Early ZS went to sleep whilst waiting for delayed charging to start, others can't cope with being switched on and off regularly either by solar or tariffs like Octopus Agile or Intelligent Octopus. VAG have made so many errors with the MEB cars it's amazing their customers persist.
5. Octopus have a series of Beta tariffs which are more for enthusiasts and sometimes the supporting cast can't always keep up.

 

[tsedge]

Thanks BugEyed, that along with Matt’s explanation makes it much clearer.