Slow DC charging with CCS - why?

[chasemarmot]

I'm wondering if anyone can shed light on a slow charging experience I had today using a CCS adapter at a non-Tesla DC fast charging station. I arrived with 30% SOC and plugged into a Shell Recharge CCS station rated at 100kW. Charging began at 130kW! But by 45% SOC charging slowed to 33kW and stayed there until I reached my goal of 80%. I have used the CCS adapter at other stations and it has sustained charging rates >50kW. Why so slow today? I can think of two possible reasons:

1) A problem with delivery from the station. But this seems unlikely since it was delivering 90-130kW for a few minutes. Also, I was the only car at the station - no power sharing.
2) My Model Y's Battery Management System throttled back on the power it would accept for some reason. It was very hot day (98 degrees) and the car had just driven 180 miles. Was the battery too hot to accept charge at a faster rate?

I like the increased charging options the CCS adapter allows. But this slow charge was a bit of a disappointment. Superchargers will usually slow me down to 25kW but only after the SOC gets high say above 70 or 80%.

Thoughts?

 

[Fourdoor]

The charging station cable has a thermistor in the plug, if it gets too hot it throttles the charging speed. I would guess that if you checked the plug it was hot to the touch. The same thing happens on V2 superchargers in hot sunny weather, some people wrap a wet rag around the charge cable end for evaporative cooling to maximize charging speed.

Keith

 

[GtiMart]

I don't believe a 100kW charger could have given you 130kW. Are you sure you haven't looked temporarily at charging speed in mph?
The 100kW units are typically 200A @ 500V. Since your Tesla maxes out a 400V, the best you can get there is 80kW, and you get less if your soc is low as the car might only request 375V then...

 

[chasemarmot]

The charging station cable has a thermistor in the plug, if it gets too hot it throttles the charging speed. I would guess that if you checked the plug it was hot to the touch. The same thing happens on V2 superchargers in hot sunny weather, some people wrap a wet rag around the charge cable end for evaporative cooling to maximize charging speed.

Keith

Thanks Keith, I'll try that out. Just to be clear, some people wrap a wet rag around the charge cable/plug at the end that attaches to the car (and in this case the CCS adapter)?

GitMart: Yes, I'm sure it was kW, not miles. I haven't used miles since the day I purchased the car. Who knows, maybe the Shell Recharge app is wrong and it is actually a 150kW station.

 

[Fourdoor]

Thanks Keith, I'll try that out. Just to be clear, some people wrap a wet rag around the charge cable/plug at the end that attaches to the car (and in this case the CCS adapter)?

GitMart: Yes, I'm sure it was kW, not miles. I haven't used miles since the day I purchased the car. Who knows, maybe the Shell Recharge app is wrong and it is actually a 150kW station.

To be clear, I don't know of anyone doing this with a CCS cable, let alone with a CCS cable and CCS to Tesla adapter... I just know of people doing it with V2 Superchargers in hot sunny weather and figured it is worth a try with the CCS. And yes, it is around the end that plugs into the car, plug into the car first, then wrap the wet rag around the end.

Keith

 

[chasemarmot]

An update to my original post. I had another slow CCS charge experience on the northern california coast when the station/plug was clearly not too hot. Arrived at Shell Recharge DC station rated at 200kwH. Arrived SOC 35%, ambient temps in the 60s, yet the car only charged at 40kW. I had even told the car I was going to the nearby tesla SC, so it had pre-conditioned. I think the BMS must be limiting the charge rate at 3rd party stations for some reason. Kind of frustrating to be at a 200kW station only pulling 40kW. I'll keep experimenting with CCS DCFC. Maybe it's something peculiar to Shell Recharge.

 

[LoneStarEve]

35kW or so is what the charging stations drop down to if the cable overheats or if they lose the signal from the temperature sensor in the cable handle.
There is an epidemic of this issue going on at the moment and why owning a Tesla vs a CCS car makes life so much easier.

 

[avs007]

A lot of the EA chargers in northern California are busted. A few months ago, I drove thru California, and used EA with great success. A few weeks ago, I did the same drive, and ended up using SC instead, because the same EA chargers I used a few months ago, wouldn't charge faster than 30kw. Most likely a busted thermal sensor in the CCS handle. I even checked plugshare plugins at the time. Some of the stations were reported that all stalls only outputed 30kw

 

[TonyS852015]

Hello,
European Tesla S driver here (2015 S85). I used to charge at SC V2 starting above 100kw and maintaining a steady 90+kw charge power until I would reach the last 20% (for a 100% charge).

I installed a CCS adapter plats week to be able to charge at SCV3 … guess what ? Since that installation (tesla does install a part in the car to limit the in power to 150W ok understand this), but since then 55Kw max form the start at SCV3 or even at SCV2 !

Not happy with this and did the tests in different SCs in France and Switzerland. Exactly same problem. So I’ll reach out to tesla next week and ask for an explanation (will post it here), but if they cannot fix this and get le the initial 90KW+ at SCV2 like I use to get, I’m switching back to non-CCS adapter.

 

[MacO512]

I've heard the same that many CCS chargers temperature sensors break and are maxing out at 30-40kwh. Can't imagine trying to do a road trip in a rivian or hummer with their big batteries, those things will need 2 hours of charging for every hour on the road.

 

[chasemarmot]

I think what several people in this thread have noted is the most likely culprit: a failure of the charger to get the information it needs from the temperature sensor leads to a protocolized down-regulating of the kw output to the 35-40kw range. It would be nice if this problem fades away as chargers get updated and kinks get worked out. It takes a lot more time to charge at 40kw than at 80 or 120. This would also indicate it's not a problem on Tesla's end, but I suppose could be a problem with the tesla/CCS adapter.

 

[Azov]

I am experiencing the same issue with IVY charger in Canada. Maximum I am getting is 45kW. The station is rates for 350kW.

 

[avs007]

I am experiencing the same issue with IVY charger in Canada. Maximum I am getting is 45kW. The station is rates for 350kW.

What was your starting state of charge, what's the outside ambient temperature, and how long were you driving before you pulled in to charge?

 

[Midnightsun]

Did you use your CCS adapter at the IVY station or the convenient Tesla plug they offer so you can plug directly into the Tesla without using YOUR adapter? The IVY Tesla incorporated plug is restricted to 50kw as it uses the Chademo protocol so all Teslas can charge there. If you use your CCS adapter and the CCS machine, you should be getting much faster charge rates than what you saw.

 

[Abdul.shaikh]

I have had the same issue l. Preheated the battery before arriving at a ivy charge station in Canada. Station rated for 150kw but max 68kw charge speed using the ccs adapter. Seems like tesla is throttling third part chargers. Tried at multiple locations with same result. Max I've gotten is 87kw at a 350kw station ( 2023 model x)

 

[GtiMart]

No ccs throttling that I've heard about, and some YouTubers get good speeds. KW is voltage * amps. Voltage is dictated by your battery and is maximum 400V when you are nearing full. All depends on the max amps of the charger. Most ccs chargers have a max of 1000V but a low max amps, which is why our Teslas don't charge that fast on them. To contrast, a v3 supercharger pushes something like 680A at peak.

Apart from that you need a toasty battery and a charger that's not broken.