DC Fast Charging Speeds

[AntAstrophY]

Hey all
Once again probably been answered before but I’ll try my luck. I own a MG4 Essence 64 (Australian spec) and I’m currently DC fast charging at a 150kw Ampol AmpCharge station and I’m only getting 75-77kw speeds fully maxed out! Also my battery was at 21%.

Does anyone understand why this is happening?

 

[ReintjeWA]

The lower (and higher) end of your SOC (state of charge) won't allow for the maximum charge rate. I would expect the charge rate to increase the closer you get to roughly 50%, and it'll slow down again progressively towards 100%.

Other than that it could just be the charger itself, there could be a fault, or sometimes one charger shares it's max load across multiple cables so to speak.

 

[gary333]

If it makes any difference I see this on some Tesla Superchargers that are badged as 150kw, however only really charge at the rate you are seeing. I am not sure if this is something set by the shopping centre to restrict the chargers. (This happens when only one charger is in use out of the 12 available so not power sharing issue).

 

[AntAstrophY]

The lower (and higher) end of your SOC (state of charge) won't allow for the maximum charge rate. I would expect the charge rate to increase the closer you get to roughly 50%, and it'll slow down again progressively towards 100%.

Other than that it could just be the charger itself, there could be a fault, or sometimes one charger shares it's max load across multiple cables so to speak.

I agree! It does both of these things in regards to my SoC but sadly it never exceeds those speeds. I’ve tried this at about 3 different stations (2 different brands).

If it makes any difference I see this on some Tesla Superchargers that are badged as 150kw, however only really charge at the rate you are seeing. I am not sure if this is something set by the shopping centre to restrict the chargers. (This happens when only one charger is in use out of the 12 available so not power sharing issue).

I thought about this. The DC chargers app says 100kw. The charger itself declares speeds of 150kw and the car software says 75kw.

What I need is a straight up comparison from other Australian mg4 drivers

 

[gary333]

Could the charger be an 800V unit? This has been mentioned before on other forums I have read that this combination is possible. With the MG being a <400V car it will only be able to pull so many amps thus only be able to charge at half the chargers rated capacity.

Can't you try plugging in to a 350Kw unit? This should give full speed?

What I wrote above appears to the case why you only get half the charge rate

Ampol explains why most electric cars charge up to 75kW rate at AmpCharge EV chargers - Electrifying Everything - by Neerav Bhatt

I asked my contact at Ampol AmpCharge Why is it that at quite a few AMPCharge sites eg Alexandria (Sydney), 400V electric cars can only charge at about

www.bhatt.id.au

 

[siteguru]

I'd highly doubt that a 150kW rated charger will be 800V architecture.

Although reading the article it does suggest this.

 

[Bam Bam]

I think someone else reported this a little while back.

TeslaBjorn does charging comparisons and he always seems to get the official charge speeds. Maybe that is a sign that Norway is living in the future and their chargers are highly capable of delivering full power and only the car sets the limit.

This is the official charging power report on the 64kwh battery MG4 from Fastned as reported by ev-database...

In reality chargers might not match their capacity for one of more of the reasons others have set out above.

I suppose you are worrying that there is a fault with your car, but it is charging at a reasonable rate by the sounds of it. Just half what you were hoping for.

 

[gary333]

I'd highly doubt that a 150kW rated charger will be 800V architecture.

Although reading the article it does suggest this.

According to the company who the OP is referring to:

“All our DC chargers provide the full supported output range of up to 920Vdc. Some of our chargers do have low current cables (200A) in order to help improve overall usability and reliability for individual and concurrent usage at each charging point”.

“With the low current cables if your vehicle’s battery voltage is 800V then you should be able to get up to 150kW of power under the right conditions. If your vehicle’s battery voltage is 400V then this would likely be closer to 75kW”.

“However, charging times are not guaranteed and can depend on your vehicle’s battery size, your vehicle’s charging capacity, the charge state of your battery and weather conditions”. We remain focused on providing a strong customer experience as people transition to EVs”.

“All things considered, we feel higher current cables can have a detrimental effect on customer experience, reliability and safety given their weight. We are consistently monitoring customer feedback as well as technological advancements to ensure we get the balance right”.

 

[Bam Bam]

On our few DC charging experiences we didn't seem to get the maximum speed. About 70kW maximum if I remember correctly on the standard range, which is supposed to go up to 88kW.

 

[Jamesrr]

100% it's 150kW @ 800V.
You see this on heaps of chargers here in Australia.
I get 144kW charging from Tesla Superchargers and the good Kempower units around NSW, ACT and SA but only 70-80ish from the "150kW" 800V units.
Completely expected.

 

[AntAstrophY]

Could the charger be an 800V unit? This has been mentioned before on other forums I have read that this combination is possible. With the MG being a <400V car it will only be able to pull so many amps thus only be able to charge at half the chargers rated capacity.

Can't you try plugging in to a 350Kw unit? This should give full speed?

What I wrote above appears to the case why you only get half the charge rate

Ampol explains why most electric cars charge up to 75kW rate at AmpCharge EV chargers - Electrifying Everything - by Neerav Bhatt

I asked my contact at Ampol AmpCharge Why is it that at quite a few AMPCharge sites eg Alexandria (Sydney), 400V electric cars can only charge at about

www.bhatt.id.au

Ahh! Interesting! Cheers mate. I guess at the end of the game the car targets an end of the market and it’s not the high end

Not that I’m fussed I think 75kW is actually decently fast.

 

[Jamesrr]

Not that I’m fussed I think 75kw is actually decently fast

Yeah, for many circumstances 75kW charge rate is fine. When doing long distance trips it does pay to use the good chargers and get the full speed experience though.

Just out of interest, what were the sites that you only got the slower charge rate?

 

[AntAstrophY]

Yeah, for many circumstances 75kW charge rate is fine. When doing long distance trips it does pay to use the good chargers and get the full speed experience though.

Just out of interest, what were the sites that you only got the slower charge rate?

Oh that was the Arana Hills Ampol in Brisbane. But doesn’t seem to matter which brand I use I get those speeds fully maxed out.

 

[Jamesrr]

Oh that’s was the Arana Hills Ampol in Brisbane. But doesn’t seem to matter which brand I use I get those speeds fully maxed out

The MG4 like many current EVs has a 400V DC system. This means that chargers which are advertised at their 800V capacity will not deliver that rating at 400V.

It certainly does matter which "brand" EV charger you use. That Ampol unit doesn't support supply of 150kW @ 400V. It's a notional 150kW @ 800V.

If you go to one of the open Tesla sites you'll see that your car can charge at up to 140kW (from around 10-50% SoC. You could also go to the Kempower based Chargefox site at Taigum Square and you'll get 100+kW as it's a 200kW@800V unit.

Brisbane is very poorly served with decent fast chargers. There's only the two open Tesla sites and that new Taigum Square site. There are unfortunately lots of those very unreliable and slow Tritium units that deliver 50kW when working, but as often as not, aren't.