Fastest DC Charging Speeds

[JBorn]

What is everyone's fastest charging speeds they've gotten so far on Ultra-Rapid DC chargers? (i.e. 350kW). I have the 77kWh variant - 72 reg model.

On Thursday, I was pleasantly surprised when I got my highest ever charging rate - Peaking 14%/168kW at Ionity Stafford (6 x 350kW)

It started charging quickly stepping up to 158kW at 4% charge and gradually climbing up to about 14% before peaked and slowly dropped. There was 2 other cars charging at the time.

About an hour earlier I had charged at Gridserve Strensham - after driving carefully at speed limits to get there, for as short a time as possible to reach a decent Ionity charger - up to 37%, as I was only getting 78kW from a "360kW" charger. I think the rapid charge may have heated the battery though, as the power bar was up to almost full afterwards, for much longer into the low percentage range... usually mine starts to reduce the blue power bar visibly below 37%

For the final 5 miles before I reached the Ionity charger in Stafford I repeatedly floored the accelerator... and let the car slow down, and repeated this until I got there. I think this probably helped the battery warm up. I could hear a cooling fan going what sounded like flat out when I got back to the car, and when I sat in the car there was quite a loud humming as if a coolant pump was running, which stopped shortly after I got in.

When I bought the car it was advertised as 135kW charging for my battery... so pretty happy that it has exceeded that. Although it is now mentioned on some websites that it can charge at 175kW so not sure if it is a hardware or software update, or a typo. I have seen a German reviewer get 170kW though, so maybe it is to do with the quality of the charging network.

Up until Thursday though, I have been getting max speeds of about 95/105/125/135kW on various different rapid chargers at the peak speed. I find that it generally seems to be consistent when you go back to the same charger.

[tuppaware]

Yeah I get about the same speed on mine. Bang on the money for the charging curve.

[QuasarBorn]

High charge rates is something I seem to struggle with in my 58KWh. I have used many Fastned chargers and never got any more than 44KW and that is at different times of year and around 30%soc. Gridserve are pretty consistent with high 60s but the best I've had was from a Porsche charger at Carnforth with 110KW output. got me from 9% to 60% in 19 mins which I really cant complain with! haha

[JBorn]

High charge rates is something I seem to struggle with in my 58KWh. I have used many Fastned chargers and never got any more than 44KW and that is at different times of year and around 30%soc. Gridserve are pretty consistent with high 60s but the best I've had was from a Porsche charger at Carnforth with 110KW output. got me from 9% to 60% in 19 mins which I really cant complain with! haha

Screenshot 2024-02-05 121039.png

My first few rapid charges were like that too, I've had to do it more frequently during my first winter, I only had one during the summer, which is when the battery would usually be at optimum temp

I reckon after starting percentage, battery temp seems to be the next biggest thing affecting charging speed from the cars side.

Of course, some chargers are just terrible too - I was at a 120kW Instavolt a couple of weeks ago, charged from 4% - 12% at 62kW, it wasn't improving.

I had somewhere to be so I changed to a Chargepoint 150kW across the road and Bingo... 135kW straight away!

At the time that was the fastest my car had ever charged

I've also had 44kW off a BP Pulse which was rated at 150kW, 67kW off a 350kW charger with many other empty stalls, etc. A few weeks ago it maxed out at 95kW at ionity Cullompton, next week same charger it got to 125kW.

With all of this my battery percentage was similar, so the only thing I can put it down to is battery temp

Hopefully one day they will add a pre heat option to the software. The hardware is already there for the charge schedule preconditioning, so it should be possible...

[QuasarBorn]

My first few rapid charges were like that too, I've had to do it more frequently during my first winter, I only had one during the summer, which is when the battery would usually be at optimum temp

I reckon after starting percentage, battery temp seems to be the next biggest thing affecting charging speed from the cars side.

Of course, some chargers are just terrible too - I was at a 120kW Instavolt a couple of weeks ago, charged from 4% - 12% at 62kW, it wasn't improving.

I had somewhere to be so I changed to a Chargepoint 150kW across the road and Bingo... 135kW straight away!

At the time that was the fastest my car had ever charged

I've also had 44kW off a BP Pulse which was rated at 150kW, 67kW off a 350kW charger with many other empty stalls, etc. A few weeks ago it maxed out at 95kW at ionity Cullompton, next week same charger it got to 125kW.

With all of this my battery percentage was similar, so the only thing I can put it down to is battery temp

Hopefully one day they will add a pre heat option to the software. The hardware is already there for the charge schedule preconditioning, so it should be possible...

With charging outputs from whatever chargers, I seen something on an American YouTube video about going round different chargers and the author found that certain charger cables were only rated for certain loads so a 400Volt car would only get half the charge rate of a 800Volt car (cos physics I=P/V) so that's something I'm going to look out for when fast charging. The max figure may also be for 800V cars, not 400V cars

[JBorn]

I've seen that or a similar video too. Yes 350kW is only achievable for 800v charging architecture, as the cables are not rated to take the amperage it would need to charge a 400v battery at 350kW. Instead, they increase the voltage to increase the overall wattage.

A lot of american chargers seem to have cables rated to only enough amperage to draw 80kW on a 400v architecture. However the cable is usally thinner too when rated for lower amperages, and most UK chargers have cables akin to an elephant trunk - unlike the ones shown in that video.

I haven't managed to see the max amperage on any cables but I guess to achieve 170kW on a 400v battery, you would need 170,000W / 400v = 425A (someone please correct me if I'm wrong)

Whereas 425A drawn on the same cable at 800v (425A x 800v = 340,000W (aka. 340kW)

Often from looking at charging provider responses to complaints on charging stations - such as my local BP Pulse, it seems that a charger can get slower and slower as some kind of fault, and needs to be physically visited by a technician to fix it. I can't really picture in my head how this is physically possible as I would have thought it is on or off, although a giant fuse getting looser and looser in it's connection does come to mind...

I know that some Tesla chargers can put more through a cable than the cable is rated for by monitoring the temperatures, so maybe faulty chargers are really a faulty sensor which is throttling the kW as a safety measure. Who knows!