150kW DC-DC converter option

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ron_b

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Help request to you lucky Taycan owners from a poor person still awaiting his lock date. :rolleyes:

In the video at start of a thread I had for a charging review by Bjorn Nyland on a Taycan 4S with small battery and base 50kW DC-DC converter he got only a 36kW charging rate. He also stated that's what Porsche had suggested would be common, although I don't recall reading that but I intend to find 800 volt chargers 99% of the time I need fast charging anyway.

So my question to owners is would somebody mind trying to charge they're taken at a 50 kilowatt charger like evgo or such and see what they get. I'm curious if the upgraded 150 kilowatt converter will improve the efficiency at 50 kilowatts. This was speculated in some posts above.

Original thread https://www.taycanforum.com/forum/threads/porsche-taycan-4s-79-kwh-charging-test-bjørn-nyland.1382/

Short cut to the offset

Be clear his story was not all doom and gloom from him, at the beginning of the video you will see 220 kw charging which is the peak for the smaller battery. He was also quite impressed that it was still going at 100 kilowatts at 79%.
 

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I’ll test it, but I don’t think it will. I think the optional DC to DC is to allow charging at 400v at FASTER than 50KW. I think the same efficiency issue will be there. But I am not sure he is right, I don’t think that is all from DC to DC conversion loss. That would be a LOT of heat generated and would imply something like 20% conversion loss. On most cars at 50 KW charging you usually don't get the full 50 KW.
 

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Of the 50kW charging stations I connected to on my trip, He's the maximum Observed Charge Rates (that is, what I saw on the center console screen during the session, accuracy not guaranteed):

1590245580853.png
 

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Well there you go, proof that what was reported at 37KW is an anomaly and that DC to DC conversion is not that bad. I think a lot of variances are from charger and conditions of the car/battery.
 
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Of the 50kW charging stations I connected to on my trip, He's the maximum Observed Charge Rates (that is, what I saw on the center console screen during the session, accuracy not guaranteed):

1590245580853.png
I love the detailed data Don, that is spectacular. If I could ask for a future column added would be the maximum current for the station which you can get from the tag on the side. I have noticed that it matters a lot on my Chevy bolt EV. As some stations are 125 amp and some 150 amp. The issue is that to get 50 kilowatts out of these hundred 25 amp stations you need to be right at 400 volts and generally the car does not get the batteries to that level until pretty late in the charge and by then it's often tapering down. Not sure what voltage the dc-to-dc converter requests, but if it is a fixed doubler as opposed to a variable converter then it would be asking for only 360 or 375 volts which may explain your times getting less than 40 kilowatts. But it's hard for me to do a complete analysis without having the raw data.

Also @epirali, I do not think it is quite a closed topic as I thought Don's car had the 150 kilowatt DC-DC converter. So I guess we would need someone with out of the upgrade to do the test and see if they can get this 47+kW which is great! I am quite hopeful though, I believe that the converter that they would use would be well above 90% efficient so I am hopeful.
 

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I love the detailed data Don, that is spectacular. If I could ask for a future column added would be the maximum current for the station which you can get from the tag on the side. I have noticed that it matters a lot on my Chevy bolt EV. As some stations are 125 amp and some 150 amp. The issue is that to get 50 kilowatts out of these hundred 25 amp stations you need to be right at 400 volts and generally the car does not get the batteries to that level until pretty late in the charge and by then it's often tapering down. Not sure what voltage the dc-to-dc converter requests, but if it is a fixed doubler as opposed to a variable converter then it would be asking for only 360 or 375 volts which may explain your times getting less than 40 kilowatts. But it's hard for me to do a complete analysis without having the raw data.

Also @epirali, I do not think it is quite a closed topic as I thought Don's car had the 150 kilowatt DC-DC converter. So I guess we would need someone with out of the upgrade to do the test and see if they can get this 47+kW which is great! I am quite hopeful though, I believe that the converter that they would use would be well above 90% efficient so I am hopeful.
I’ve been doing a bit of research. I think it is to do with the 400 or 600 volt architecture at the station. The 400 is effectively 2 phases meaning the charger on the street is limited in being able to get charge rates above 50KW. But 600 volt and above can deliver more that 50KW so you need the onboard upgrade to receive that. What I’m not sure about is the 800 volt IONITY chargers connected to 800 volt car. I suspect that’s something to do with both being 800 and being able to deliver and accept at 800 volt etc.
 



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