FMinMI
Member
Thought you could get 50kW with the CHAdeMO...If you want a 35kW adapter get the chademo one
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Dc combo for USA port
- Thread starter Wkwjsrjal22
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But you can't really get that. 50kW is the maximum you can possibly get. At a low SOC the voltage is too low to get that and you might start out at 35kW, and as the SOC increases the charge rate eventually will increase to ~45kW.
FMinMI
Member
OK. But I would have thought that at a low SOC, it would be faster, then ramp down as the SOC goes up. So you are saying that if I start at 20%, it will be 35kW, but as it goes up, it will stay at 45kW, all the way to 100%? Doesn't seem right. Ironically, I bought one over a year ago used. Never had a chance to test it yet...
FMinMI
Member
Sweet. I am all ears for your findings...
Was it $660 shipped all-inclusive? Or are there custom charges as well?
The CHAdeMO adapter is limited to 125A, but most CHAdeMO sites are limited to ~100A. So you speed is your voltage(SOC) * Amps. So at 350v the most you can get is 35kW. That increase slowly until it peaks at ~40kW @ ~60%, but will still taper toward the top just like Supercharging.
If you have a 350v battery (old 60s/70s/75s, or the special 85 pack) it would be even slower.
Then you must have the good CHAdeMO sites that support the full 125A that the adapter does.
and......a lot of time you are losing ~6-7kW to battery heating.
I took this pic about 1 millisecond after it switched from 48 to 47 KW.
But you get the idea. Yah Could be. I don't use that particular site a lot. (Like almost never as it is in my home town) But we were starting an unexpected tri and just wanted to "tank up" a bit.
And there is a good coffee spot close by. 
I'll be happy if the CCS is a tad smaller. These chademo adapters are bulky suckers. Life savers though. At least in this province.
Power available via CHAdeMO charging is limited by the max Amps (100A or 125A). As a result, the charging curve is totally different from what people experience at superchargers. Charging power in kW is roughly volts*amps, and the charging voltage is dictated by your car's pack voltage, which is low when the battery is empty and high when the battery is full. Charging a Tesla via CHAdeMO, you'll get a higher charging rate the higher your SOC is up to the point where you start hitting the taper imposed by the battery management system. Functionally, if you start charging at 20%, you might get 30-35kW which will gradually rise--as the battery fills up and therefore pack voltage increases--to ~45kW by the time your battery is at 85-90%. After that point, it will taper off just like supercharger as your battery gets totally full.
The exact power values and when you reach them will depend on your car model and battery pack size, as well. So, what you get in reality might be a bit higher/lower than what I wrote above or the point you reach max power might be at a slightly different SOC.
israndy
Supercharger Hunter
I have observed this behavior and find it curious.
You are saying that at 350v when I pull into the charger I am able to put 100 amps into the car and so it charges at 35kW?
Is the charger only putting out 350v? Wouldn't they be trying to charge the car at 400v? If the car is being fed 400v@100 amps I would be getting 40kW the entire time the car is charging until the BMS taper.
But when I pull into a CHAdeMO charger I typically charge at less than 150mph that slowly rises to 200+MPH before the BMS taper at ~85%
I just don't understand the math behind the slow rise, what is causing the speed of the charge to change as the battery fills?
You are saying that at 350v when I pull into the charger I am able to put 100 amps into the car and so it charges at 35kW?
Is the charger only putting out 350v? Wouldn't they be trying to charge the car at 400v? If the car is being fed 400v@100 amps I would be getting 40kW the entire time the car is charging until the BMS taper.
But when I pull into a CHAdeMO charger I typically charge at less than 150mph that slowly rises to 200+MPH before the BMS taper at ~85%
I just don't understand the math behind the slow rise, what is causing the speed of the charge to change as the battery fills?
The charger matches the voltage to the battery pack voltage. It's putting out 100 or 125 amps the whole time up until the taper, but the voltage it is delivering is rising as the pack voltage rises--they're matched. Then it's simply V*A=kW. Once the battery hits the taper, even though the voltage continues to rise as the battery cells fill up even more, the delivered amperage decreases and does so faster than the voltage rises. As a result, the power goes down.
Superchargers and AC charging works basically the exact same way. Only with superchargers, they can output high enough current (amps) to compensate for the low voltage when starting from a low SOC. And with AC charging, the electricity is delivered at a set voltage from the EVSE/outlet determined by the feeder circuit but it goes through the car's onboard charger which converts to DC and adjusts the voltage via DC-to-DC conversion to match the pack voltage.
If I recall how this works:
Basically lithium ion batteries are considered "empty" at 3.0V and they charge using constant current until the voltage goes to 4.2V at which point the charger holds the voltage constant while tapering the current down.
For a 350V nominal pack (3.6V nominal for a single cell) the range is then 292V through 408V. When you're very low in SoC, you'd start your charge at say 293V 125A which gives 36.625kW which seems to approximately match what you're seeing and makes me happy that my maths seem to work out.
Basically lithium ion batteries are considered "empty" at 3.0V and they charge using constant current until the voltage goes to 4.2V at which point the charger holds the voltage constant while tapering the current down.
For a 350V nominal pack (3.6V nominal for a single cell) the range is then 292V through 408V. When you're very low in SoC, you'd start your charge at say 293V 125A which gives 36.625kW which seems to approximately match what you're seeing and makes me happy that my maths seem to work out.
israndy
Supercharger Hunter
Ummm, well, it doesn't stay the same at Superchargers either. You've seen this, right? At Superchargers, it starts off really high and then only goes down.
As people have just been explaining, the Superchargers can send a lot more current, so it's all pretty much being limited by what the battery will allow.
As people have just explained, with CHAdeMO, it's capped on the current level, so it's sending 125A regardless, at whatever voltage the battery can take at that moment. As as batteries get more full, their voltage rises some. So on a pack that is named as one of the "400V" ones, when it is depleted some, it will have maybe 385V or 390V. As it charges up, that voltage rises and rises to about 400V while the current stays at 125A. That means the power in kW and miles per hour number are rising too.
At some point, the tapering curve does take over, though, where the max kW needs to start slowing down, so then you will see the amps start lowering down from 125A, etc.
israndy
Supercharger Hunter
Yes. Also, battery conditioning (heating) will consume a lot of the available power for the first ~half of the charging session. On a Model 3, that’s roughly 7 kW of power that isn’t going into the battery.
Edit: I see that @SigNC already mentioned this
It was $660 shipped, all in. UPS Worldwide Express Saver.
Sadly, I have some bad news to report. I couldn’t get it to work, at least with Electrify America that I tried. Got this error below. They seem pretty responsive so far - promised a refund if they couldn’t get it to work. I was given a software/firmware update package but I can’t get it to show up when connected to my computer, so I’m not able to do that at the moment. That’s where I’m at now.
^^^
The above should probably be reported in Setec CCS to Tesla Adapter, to avoid confusion.
Can you (probably best in the other thread) post a Plugshare link to the above EA site and/or just the address? EA isn't exactly the pinnacle of reliability so it is unknown to me whether that DC FC was working to begin with.
The above should probably be reported in Setec CCS to Tesla Adapter, to avoid confusion.
Can you (probably best in the other thread) post a Plugshare link to the above EA site and/or just the address? EA isn't exactly the pinnacle of reliability so it is unknown to me whether that DC FC was working to begin with.
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