Actual charging time almost 2X longer vs predicted.

[MattU]

I was just charging at an Electrify America station. I arrived with charge of 37% and had target charge of 85%. The initial estimate was that target charge would be reached in 15 minutes (which is about what I'd expect). The session ultimately took 28 minutes. The estimate did continuously update over time but was continuously over optimistic. Thoughts on what was going on here?

Thanks!

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[daveo4EV]

https://www.taycanforum.com/forum/t...my-taycan-charge-as-fast-as-i-want-it-to.779/

there are soooo many factors that go into charging speed for any given charging session

with out logs from both the vehicle and the charging station it's impossible to tell where the the charge rate was being adjusted…

from your two pics it doesn't seem overly "slow" for your given circumstances (SOC starting at 37% being a major factor - maximum charge rate only occurs below 35% SOC)

temperature is the "main" consideration (battery temp and outside temp)
the next main consideration is battery SOC and where you're at in the charging taper curve
then you have what the charging stall is capable of providing in terms of power

the 5% to 80% in 21 minutes is the ideal/optimal behavior (Porsche's official written claims) - but it's aspirational in nature but not common in terms of real world performance…its' rare but possible - I have personally experienced it in Taycan and Macan when all the conditions are right - so it is achievable in the real world…just not "common"

I recently charged from 10% to 80% in 26 minutes at a 150 kW station in Aptos, CA - this is only 5 min slower than "optimal" for a 350 kW station - so again in the ball park and not unreasonable.

you're 26 min stop for 84% is in the ball park of 'expected normal' charging stop and normal performance given all the myriad of variables that go into a fast charging session and it's performance.

 

[Throb]

Having had two Taycans before my Macan Turbo, I would say the Macan charges slightly quicker than the Taycans, even though on paper they should charge at roughly the same rate.

 

[MatC21]

I guess depends if you had the facelift or not. Pre facelift is probably slower, the new facelift is definitely faster.

 

[MattU]

Of course I'd like to see the car charge as fast as possible, but my issue here was more about the inaccurate prediction of charge time. The car should have almost all the inputs it needs in order to make a good prediction. It knows: indoor and outdoors temps, SOC curve, input voltage.

 

[PrudentOcean]

I've only charged at Electrify America L3 chargers (no L2 at home) and the completion estimates have always been spot-on for me.

Did you use a shared charger? Maybe a vehicle charging next to you impacted the current that the charger could deliver.

 

[Petzi]

Of course I'd like to see the car charge as fast as possible, but my issue here was more about the inaccurate prediction of charge time. The car should have almost all the inputs it needs in order to make a good prediction. It knows: indoor and outdoors temps, SOC curve, input voltage.

but the car can not know the ability of the charger. it gets the information about the type of the chartger and its nominal capabilities. if the charger can not deliver the expected chartging performance it will last longer. how should the car predict the behevior of the charger? i think we all agree that the macan is able to charge from 10-80 in 22min. should it take longer for your car all the time., you have a technical probnlem.

 

[MattU]

but the car can not know the ability of the charger. it gets the information about the type of the chartger and its nominal capabilities. if the charger can not deliver the expected chartging performance it will last longer. how should the car predict the behevior of the charger? i think we all agree that the macan is able to charge from 10-80 in 22min. should it take longer for your car all the time., you have a technical probnlem.

Thanks, @Petzi. It seems pretty straightforward for the car to measure directly what the charger is delivering or for the car to query the EA network for the capability of the charger.

 

[MattU]

I've only charged at Electrify America L3 chargers (no L2 at home) and the completion estimates have always been spot-on for me.

Did you use a shared charger? Maybe a vehicle charging next to you impacted the current that the charger could deliver.

Thanks @PrudentOcean. There were cars in all of the adjacent chargers but there was only a single cable coming from the charging unit I was using. This was labeled as a 350kW charger. On the PCM display (the posted screenshots) the max I saw was 120-130kW. I'm not sure what to expect on the display given a 350kW EA charger. Do you remember what you saw displayed?

 

[EdInSanDiego]

Well the 15 minute target is just plain wrong and nonsense. You were charging at 121 kW at the time and wanted to add 48% of usable capacity. Total usable is 95 kW-h so you wanted to add around 46 kW-h. If we incorrectly pretend the car would consistently charge at 121 kW then that would take 23 minutes, but of course the rate of charge will always slow down after 80% so obviously the real time would be slower than that.

 

[PrudentOcean]

Thanks @PrudentOceanOn the PCM display (the posted screenshots) the max I saw was 120-130kW. I'm not sure what to expect on the display given a 350kW EA charger. Do you remember what you saw displayed?

I’m writing this while sitting at a EA 350 kW charger and it is currently supplying about 100 kW.

 

[PrudentOcean]

Also check if the screen says “Balanced Charger” somewhere. If it does (like on the charger I just used) then you are sharing the available capacity (up to 350 kW in my case) with another charger.

My phone didn’t capture it well but it is in the upper left.

 

[Etmaniac]

Does the voltage also not have an impact? Ionity in EU are 800V chargers, Tesla V3 and below 400V.

 

[Was87911]

I had my first charging session in the wild yesterday on the free EA network. I plugged into a 350kw charger with 25% and target of 90% trying to burn up as much of my 30 free minutes as I could. It was in the wee hours of the morning so so one was waiting on the chargers for me to squeeze out those last few drops. The charge started at 195kw and dropped to 70.6kw by the time my 30 minutes was up and only made it to 87%. Since the charge started at "only" 195kw from the 350kw capable charger, is it of much benefit to seek out the 350kw charger vs a more common 150kw? If it is more about the car's ability to take a charge than the charger's ability to give it, is there a benefit to chasing the higher powered chargers?

 

[seabird]

Of course I'd like to see the car charge as fast as possible, but my issue here was more about the inaccurate prediction of charge time. The car should have almost all the inputs it needs in order to make a good prediction. It knows: indoor and outdoors temps, SOC curve, input voltage.

Doesn't look like it was inaccurate, though. The initial estimate in the first minute of plugging in is based on what the car asked for from the charger...and when it didn't deliver that, the estimate was revised.

50kW in 15 minutes is possible at 200kW+, which is possible at 37% SOC on a 350kW charger. The only thing that didn't happen here is the charger delivering 200-240kW as it should have.

At 120kW, that charge taking closer to 28 minutes is exactly when it did finish.

This was labeled as a 350kW charger. On the PCM display (the posted screenshots) the max I saw was 120-130kW. I'm not sure what to expect on the display given a 350kW EA charger.

You can expect up to ~250kW depending on the condition of the car, the charger, and the local power supply.

Getting only 120kW means that there was something limiting availability at the charger. Either there were too many other cars charging at too high a rate at the station, there was a cable cooling problem, or the unit was de-rated because of some other issue outside you or the car's control.

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