DeathStar

Just bought a very gently pre-owned 11 month old EQS580. My 4th EV. Fantastic car, couldn’t be happier!

I do have an issue with AC charging it. Seems like it starts at >9kW but slows down over time to <7kW.
I’m i the US using 240V 2 phase chargers. Tried different chargers, here at home and at work that all worked great with my Audi e-Tron, so it Must be the EQS.

Any ideas?

Utopia Texas

I do not know the reason why but my 2023 EQS 580 SUV charges that exact same way here at home.
I charge 20%-80%. Must be in the software and battery temperature management. Did not notice this last Winter and my area is now seeing 95F-101F temperatures lately.

nath_h

I've had several EV's, also. I've always had variability with Level 2 charging over time. Usually we're talking about overnight charging on Level 2, or a long time at work, so it really won't make a ton of difference. The EQS might be changing the speed for reasons regarding optimizing the battery health?

On a side note, we're on a road trip right now in our EQS. It has been awesome! On a 350 mile leg down, we charged once for about 10 minutes, just to be sure we had plenty of power. I think we could have made it without stopping. And, we tried no regeneration for the first time...the car just rolls and rolls and rolls, due to it super low drag. The range was far closer to the stated range when we left, unlike our Jaguar, which seems to eat up power much quicker than stated/starting range on the highway.

hlothery

Check your breaker capacity on that line, and make sure your charger is set to that appropriate capacity. A 40amp circuit (ie a 40 amp breaker) will charge at about 7kW. However, my 240v line with a 50amp breaker and my ChargePoint set to 50 amps charges at 9.4/9.5kW. The car is capable of that, but adjusts depending on the power it is fed.

guess2098

that is exactly same thing happens to me. I dont really care because overtime the cable and plug gets pretty hot if it is running at its max rate (240v 40A) with my taycan. but with Mercedes, 40A in 1st hr and slowly goes down to 30A, cable and plug are warm not hot which I dont really worry about it. maybe add about extra 1.5 hr of charge time

AppleFan1

The electrician I hired also installed a 50 amp circuit and I get uninterrupted 9.4kW.

DeathStar

I have tried 3 chargers, 2 at work an one at my house. All 3 chargers are 40A, wired to 48A circuit breakers with the correct cables to support uninterrupted 40A currents. Other EVs charge just fine without degradation over time. It’s the EQS, I’m sure. At work, we are sharing the chargers between multiple cars and the slow EQS blocks others from charging. I’m sad to see that a 2023 still has that issue.

hlothery

[QUOTE=DeathStar;8798381]I have tried 3 chargers, 2 at work an one at my house. All 3 chargers are 40A, wired to 48A circuit breakers with the correct cables to support uninterrupted 40A currents. Other EVs charge just fine without
Something is wrong. My circuit (50amp breaker) delivers 40amps of current. My EQS charges at 9.5kW. Your situation doesn't make sense. The EQS has a 9.6kW charger built in. I would have it checked out.

AppleFan1

[QUOTE=hlothery;8798397]I have a stand-alone circuit breaker with ChargePoint wall mounted charger just for the EQS charging. Maybe the problem with the OP is that he doesn’t have the stand-alone breaker. If he does, I have no clue why he’s having problems.

guess2098

btw, both of my EQS580 SUV and sedan acting the same way like yours. same charger to my Taycan doesn't. I dont think it's the car issue. there are people has same posted on other forum too.
my charger is made by Porsche, it can adjust output amp but I think all the chargers have same option

hlothery

[QUOTE=AppleFan1;8798401]This is the same as my setup, and could be the solution to the OPs problems.....not sure. But, unless something is malfunctioning, I am having trouble understanding how the EQS could be at fault here,

Utopia Texas

As I stated above I believe the EQS slows the KW down related to how hot the batteries become during charging as a safety mechanism. I am on a 50 amp breaker here at home and it’s over 100F where the EQS is parked. My charging sessions lately start at over 9KW and as the charging gets closer to finish at 80% it drops to the 7KW range. I’d bet those of you getting a 9KW charge the whole time have cooler relative temperatures where you are located. The cable directly out of my charger is registering 145F.

hlothery

I'm in San Antonio. I have actually not noticed what the charge rate is right toward the end of charging. Most of the time it is charging in my garage (very hot) at 9.4-9.5kW. I look at the time predicted, and that usually is very close. I'm charging now, so I'll try to watch it tonight.

Addendum: So, temp today 100 degrees, Heat index 108....probably a little hotter in my garage. Charged from 41% to 80% in a little over 5 hours. 9.5kW most of the time, slowed to 8.8kW after 73% reached. Never lower than that. Not arguing.....just FYI. I would suggest circuit problems if this is not happening for others. My experience with the EQS charging, both at home and commercial, is that it is fast.

DeathStar

hlothery, thank you for your observations. I will try to get this resolved at my local Mercedes dealer.

Diesel Benz

No knowledge here but I'm thinking of the car spending a decent power for battery and charging electronics cooling towards the end of the charging session (the plug providing 9.5 but the battery only gets a portion of that which is reported at the cluster and mercedes me). @hlothery charged the car when it was pretty hot but not from 20% to 80%, perhaps the battery did not get as hot as for the OP. This assumes that the OP also charged at quite high ambient temperature, not sure how much difference it makes.

My plug-in hybrid has a much smaller battery and charges at 11 kW up to 80% SOC but I never charge at 100 F.

Jonate1971

Check if Eco-Charging is on. This may be the issue.