Public 7.2kw only getting 3.21kw

[MacG]

Apologies if it a repeat of something else on here earlier.
Owner of a new Trophy SR.
I decided to go to my local Tesco to top up my battery from the 7.2kw free charger. Plugged in and all was good. I decided on a sneaky fry-up with the money saved from not having to fill up with diesel.
I checked the charge after a bit to notice that it is at 93% but only achieving 3.31kw.
I understand it gets a bit slower in the final few % before full but is this a normal experience?
Only 4 days into the EV experience…..

 

[weedavemac]

Was any other car sharing the charger?
Does the charger state that it runs at 7.2 kw on it?

My thinking being that even if it is rated at 7.2, that could be being split/shared resulting in 3.31.

 

[N2STY]

Can be a few reasons.

If 2 cars share the same charger they can split the load

Wrong type 2 cable if its a 16amp and not 32amp cable easily done as 16amp cost less so it gets over looked

And some times you just don't get advertised speed tesco may want to 1/2 there bill

After a few more charges you will get a better understanding if something is wrong

 

[Lovemyev]

I agree with all of the comments and suggestions from other members above.
Just to add, that on the original ZS EV the charge rate will already starting to throttle back, to around 3.6 kW at around the 95% mark anyway.
This is completely normal on the original ZS EV and I think it will be similar on the Gen2 model.

 

[N2STY]

PS the easy way to tell the difference in 16amp and 32amp cable
There should be writing down the length of the cable normally like this

So that's a
32amp 3 phase 5x6mm²
A single phase will be 3x6mm²
On a 16amp cable it's normally 5x2.5mm² on 3 phase and 3x2.5mm² on single
Oh and X is sometimes marked as G like my picture

 

[Lovemyev]

PS the easy way to tell the difference in 16amp and 32amp cable
There should be writing down the length of the cable normally like thisView attachment 8804
So that's a
32amp 3 phase 5x6mm
A single phase will be 3x6mm
On a 16amp cable it's normally 5x2.5mm on 3 phase and 3x2.5mm on single
Oh and X is sometimes marked as G like my picture

Sometimes it is printed on the actual type 2 plug as well.

 

[MacG]

Was any other car sharing the charger?
Does the charger state that it runs at 7.2 kw on it?

My thinking being that even if it is rated at 7.2, that could be being split/shared resulting in 3.31.

Ah, possible. There was a MK1 ZS on the other side. That said initially I would as getting over 6.6 kW

 

[MacG]

PS the easy way to tell the difference in 16amp and 32amp cable
There should be writing down the length of the cable normally like thisView attachment 8804
So that's a
32amp 3 phase 5x6mm
A single phase will be 3x6mm
On a 16amp cable it's normally 5x2.5mm on 3 phase and 3x2.5mm on single
Oh and X is sometimes marked as G like my picture

I definitely have a single phase 7 kW 32A.

 

[Marc]

I've noticed that around 68-69%, the charge goes down significantly. I was charging yesterday at roughly 60% and was charging 7 kW no bother. Once it hits high 60's, it'll significantly reduce the charging speed.

 

[hmadsen]

I've noticed that around 68-69%, the charge goes down significantly. I was charging yesterday at roughly 60% and was charging 7kw no bother

I've noticed that around 68-69%, the charge goes down significantly. I was charging yesterday at roughly 60% and was charging 7kw no bother. Once it hits high 60's, it'll significantly reduce the charging speed.

I wonder why..

When DC charging mine does full speed until 80%, and then it drops to about 30 kW from 80-90, and at 90% it quickly drops even lower.

If the CCS charger is "allowed" to do DC charging at 20 kW and above, until over 90% i wonder why the AC charger would drop off already at 70% and when it even does a lot less kW than the DC charger does even at 90%

 

[Kithmo]

I noticed with SWMBO's 5, on Tesco 7kW chargers, although they're supposed to put out 7 kW each side, if someone plugs in to the same post, the rate drops. One time a Tesla plugged in and the rate went down by half, another day a Merc ECQ plugged in and it dropped to 5.5kW. Not noticed it on my ZS though.

 

[Marc]

When DC charging mine does full speed until 80%, and then it drops to about 30 KWh from 80-90, and at 90% it quickly drops even lower.

If the CCS charger is "allowed" to do DC charging at 20 KWh and above, until over 90% i wonder why the AC charger would drop off already at 70% and when it even does a lot less KWh than the DC charger does even at 90%

Yeah, I'm not entirely sure why it does that. I've only charged using 7kw, haven't touched the DC yet. Will probably wait till it gets pretty low then do a good top up.

 

[N2STY]

i wonder why the AC charger would drop off already at 70% and when it even does a lot less KWh than the DC charger does even at 90%

This will be because the AC charging is using the cars BCM to look after the battery and balance the cell a lot better than DC

 

[hmadsen]

This will be because the AC charging is using the cars BCM to look after the battery and balance the cell a lot better than DC

This might be the explanation, but still, dropping below 7 KWh at 70%, still seems insane.

 

[N2STY]

This might be the explanation, but still, dropping below 7 KWh at 70%, still seems insane.

Suppose it depends on how out of balance the batteries are that probably why when full it needs to stay on over night every now and then get a really good balance in

 

[hmadsen]

Suppose it depends on how out of balance the batteries are that probably why when full it needs to stay on over night every now and then get a really good balance in

Yeah, mine takes quite some time, from the time it says 100% until it actually disengages the charger and makes the charger say "Battery is full"

 

[Jomarkh]

The car should not reduce the current on a Type2 until it reaches 100% the drops it to 300-500w until the balance is complete.

 

[weedavemac]

The car should not reduce the current on a Type2 until it reaches 100% the drops it to 300-500w until the balance is complete.

Agreed. My home charger adds the same amount to my battery per hour regardless of the state of charge of the battery. In my case, 11% per hour (MG5 LR)

 

[Lovemyev]

The car should not reduce the current on a Type2 until it reaches 100% the drops it to 300-500w until the balance is complete.

Can not speak for the face lift model I have now, but on the ZS EV Gen 1 model it will pull 7.0 kW from a low SOC and right up to about 96 - 97% SOC.
Then at this point, the car will start throttling back on the demand supplied from the wall box.
At this point, it will reduce down to 3.6 kW.
Then at 100% it commences the balancing cycle, it pulls back again on the demand to around 800 Watts then down again to 500 Watts.
Just before it finishes the balance, it will finally drop to around 175 Watts.
Shortly after this, it will finish the balance and automatically place the wall box back into standby mode.
This behaviour can be witnessed on a home energy meter, if you can be bothered to stick around and watch it !.
Ask me how I know ?‍ .