Charging at home well below 7kwhr

[SDP79]

I have returned from a relatively long journey - round trip Chelmsford to Norwich 165 miles - more of that on another thread later. I am with Octopus Go so have the 5p rate 1230 to 0430. Been charging over night and still on going. Max charge through the cheap time was just over 6KW/hr. Then dropped to 1.139 KW/hr. Not too concerned about this as I must assume that this is the so called balancing charge. But the below 7Kw does raise questions. Is this the car throttling the charge or the charger not performing as it should? The charger is a tethered type 2 ChargedEV smart charger and the figures I have come from the app. Want to know if I should moan to MG, the Charger people or is this just how it works?

 

[biffo]

I think the car is listed as 6.6kWh on AC - so this is as much as it will use from the charger (or at least, as much as it will put into the HV battery, may consume more due to inefficiencies, etc).

Same idea as using an 18W phone charger on one that only accepts 5W - the charge rate for both these is only as much as the device can use, not based on how much the charger (or, to be semantically correct, the unit which provides electricity at a specific voltage and current, as technically the charger is built into the car ) can provide.

So, if the car starts to use only 1.139kWh for balancing, then that's all it wants. Hope this helps in some way.

 

[SDP79]

Thanks for this, so the car is setting the charge rate that it can mange. So everything is as it should be.

 

[Petriix]

kW is how power is measured - the charging speed in this case; kWh is a measure of total energy (consumed or stored). 'kW/Hr' makes no sense whatsoever.

The onboard charger is rated at 6.6kW but I believe the actual energy stored will vary with the local voltage. My Zappi EVSE regularly reports 7.3kW being drawn, although I would imagine that the car would end up storing that at roughly 6.3kW after accounting for charging losses.

 

[TiMoleseyEV]

kW is how power is measured - the charging speed in this case; kWh is a measure of total energy (consumed or stored). 'kW/Hr' makes no sense whatsoever.

The onboard charger is rated at 6.6kW but I believe the actual energy stored will vary with the local voltage. My Zappi EVSE regularly reports 7.3kW being drawn, although I would imagine that the car would end up storing that at roughly 6.3kW after accounting for charging losses.

Hi could you please tell me what charge mode you use to get 7.3KW? I am using Eco++ to get timed charging and only ever get 3.5KW max

 

[Kithmo]

Hi could you please tell me what charge mode you use to get 7.3KW? I am using Eco++ to get timed charging and only ever get 3.5KW max

7.3 including losses.

 

[biffo]

Hi could you please tell me what charge mode you use to get 7.3KW? I am using Eco++ to get timed charging and only ever get 3.5KW max

This might be a daft question - but is your wall unit/charger a 32A 7kW or a 16A 3.5kW?

 

[Petriix]

Hi could you please tell me what charge mode you use to get 7.3KW? I am using Eco++ to get timed charging and only ever get 3.5KW max

I hit 7.3 in Fast mode or when using a timed/smart boost in Eco or Eco+. Is it possible that your Zappi is configured to draw a maximum of 16a? Check with your installer as there may be a reason for this, or it may be a mistake.

 

[Jomarkh]

Hi could you please tell me what charge mode you use to get 7.3KW? I am using Eco++ to get timed charging and only ever get 3.5KW max

Have you got solar panels?

 

[Slipstream]

I think the car is listed as 6.6kWh on AC - so this is as much as it will use from the charger (or at least, as much as it will put into the HV battery, may consume more due to inefficiencies, etc).

Same idea as using an 18W phone charger on one that only accepts 5W - the charge rate for both these is only as much as the device can use, not based on how much the charger (or, to be semantically correct, the unit which provides electricity at a specific voltage and current, as technically the charger is built into the car ) can provide.

So, if the car starts to use only 1.139kWh for balancing, then that's all it wants. Hope this helps in some way.

 

[Slipstream]

I have returned from a relatively long journey - round trip Chelmsford to Norwich 165 miles - more of that on another thread later. I am with Octopus Go so have the 5p rate 1230 to 0430. Been charging over night and still on going. Max charge through the cheap time was just over 6KW/hr. Then dropped to 1.139 KW/hr. Not too concerned about this as I must assume that this is the so called balancing charge. But the below 7Kw does raise questions. Is this the car throttling the charge or the charger not performing as it should? The charger is a tethered type 2 ChargedEV smart charger and the figures I have come from the app. Want to know if I should moan to MG, the Charger people or is this just how it works?

Home chargers charge at 6.6kw although they clam 7kw.

 

[Petriix]

Home chargers charge at 6.6kw although they clam 7kw.

6.6kW is just about the maximum an EV can actually store from a 7.2kW supply after charging losses. It's a limitation of the car's on board charger. The EVSE could offer 22kW and the car would still charge at 6.6kW (unless it has 3 phase charging).

 

[TiMoleseyEV]

Update. Zappi advised a config change to maximise the Grid capacity. I updated it and a the whole thing died completely. Zappi are now coming to resolve on Thursday. At the moment I have no solar panels but they, along with batteries are being installed on Wednesday. Thank goodness for the granny charger. It takes two nights of 7 hour economy 7 electricity, but it’s helping me survive

 

[TiMoleseyEV]

Have you got solar panels?

They are coming on Wednesday, also a battery array.

 

[Petriix]

Was it just the Zappi that died?
Is it possible that it was installed on a 16a circuit for some reason?

 

[TiMoleseyEV]

This might be a daft question - but is your wall unit/charger a 32A 7kW or a 16A 3.5kW?

32A 7kW