I was looking at a video of the Taycan motorised charge port and the thing that struck me was how huge the socket and connector is. So many pins! How is that Tesla can create such a svelte simple connector whilst others have a bunch of pins, sometimes even double stacked like CC? Are Tesla just that much smarter or will they be unable to take advantage of faster charging speeds etc. later on?
why are Tesla charge connectors so much smaller than CCS etc.
- Thread starter angelman
- Start date
Tesla made some fundamental tradeoffs by the smaller connector. They basically made it so the switching from DC to AC charging has to be done by the charger circuit, since the Tesla pins handle both DC and AC. CCS/J1772 completely separated the pins so you don't have to do any internal switching, you just have the DC charging pins directly connected to the DC circuitry and the AC pins connected to the AC circuitry.
Also, keep in mind Tesla uses the 'Type 2' connector in the EU since they handle 3-phase power. Same compromise as in the US, but it's larger since it has more pins for additional 3-phase power support. The Type 2 connector is larger than the US Tesla charging port.
I believe CCS is also rated for 1000V usage, whereas the Tesla ports are only rated for up to 500V. This has to do with separation distance between the two pins so therefore the CCS is inherently going to be a bigger connector. The Taycan is the first car I think that is supposed to utilize the 1000V, so it actually needs the CCS separation.
If Tesla ever decides to move to a 1000V system (currently they use 500V), then the connector would need to be redesigned. There's not a ton of reasons to actually move to a 1000V system for cars, as far as I can tell. For trucks (semis, etc), the higher voltage could be very useful since you no longer need to use such large connectors. Honesty, it seems to me the 1000V that the Taycan is advertising is mostly marketing than anything else.
Also, keep in mind Tesla uses the 'Type 2' connector in the EU since they handle 3-phase power. Same compromise as in the US, but it's larger since it has more pins for additional 3-phase power support. The Type 2 connector is larger than the US Tesla charging port.
I believe CCS is also rated for 1000V usage, whereas the Tesla ports are only rated for up to 500V. This has to do with separation distance between the two pins so therefore the CCS is inherently going to be a bigger connector. The Taycan is the first car I think that is supposed to utilize the 1000V, so it actually needs the CCS separation.
If Tesla ever decides to move to a 1000V system (currently they use 500V), then the connector would need to be redesigned. There's not a ton of reasons to actually move to a 1000V system for cars, as far as I can tell. For trucks (semis, etc), the higher voltage could be very useful since you no longer need to use such large connectors. Honesty, it seems to me the 1000V that the Taycan is advertising is mostly marketing than anything else.
Eno Deb
Active Member
The maximum current that can be safely used with the Tesla connector may also be more limited (since the contacts are smaller). So far Tesla never exceeds around 320A (which at 375V provides 120kW power), although EPA documents and teardowns suggest that the Model 3 may be able to accept over 500A. Tesla doesn't publish the specs for their connector, but it may be the bottleneck that limits the charge rate. The CCS connector, on the other hand, is specified for up to 500A.
The Porsche is supposed to use 800V for charging. We'll have to see how long they can sustain those very high charge rates, but if the charge curve looks anything like what we've seen on the Audi SUV, it may actually shorten charge times very significantly.
Tesla should be changing to the CCS charger in North America soon. They have already done that in Europe.
Thanks for this great breakdown of the different systems.
In summary Tesla could make their connector smaller because they have a more integrated/sophisticated onboard charger compared to other EVs which may not even have an onboard charger (why Tesla can just plug straight into a 14-50 outlet).
Tradeoff maybe that in the future Tesla won't have access to very high Voltage chargers but they may not really be that practical or useful at least in the near or mid future..
More or less correct summary?
Eno Deb
Active Member
Not really. All EVs have an onboard charger, but it is not being used when DC charging (the whole point of DC charging is that the power isn't restricted by the internal charger). And charging from a 14-50 outlet is nothing special (it's very slow compared to a supercharger or CCS charger).
I think what @Kirby64 was referring to is that Tesla's proprietary connector requires a high-power relay in the car to be able to switch the connector's power pins between the AC onboard charger and the DC circuit (which goes directly to the battery). CCS, on the other hand, has separate pins for AC and DC charging.
Last edited:
You're right, the CCS connector seems specified for higher overall current potentially. It's unclear what Tesla can potentially push through their connector though. Time will tell. The charge port is a pretty small piece though; if it really is the bottleneck, I wonder how difficult it would really be to retrofit that into older cars? People replace them in the Model S all the time.
Regarding charging voltage, that ultimately has absolutely no effect on how fast a car can charge. Obviously higher voltage means getting to higher total power is easier since you need less current, but if I charge at 800V my total power input still doesn't change, I just potentially use less current. You can't beat the C rate of a battery. Charging at 350kW is going to annihilate the Taycan's battery, I think, unless it's only for very very short periods of time.
There is legislation in effect in Europe, with additional requirements imposed in individual countries related to charging that have forced Tesla's hand. What made it easier was that Tesla already used a modified Type 2, so they didn't have to make any changes for AC charging.
In North America there is no push on DC charging standards, Tesla is dominant, the next best sellers are CHAdeMO-based, the major deployers of CCS are two companies that exist only because companies had large fines, and Tesla doesn't use J1772 for AC charging.
quantumslip
Member
Side question, how do cars with the 800V battery charge on the 400V chargers? Do they have some internal DC-DC booster, or is the battery structured in a way where it can charge off of 400V directly (slower than off of a 800V compatible charger of course).
It probably switches between one bank and another. Adding a DC-DC to go from 400->800 would be cost prohibitive I imagine.
And just wait until the Asian countries and CHAdeMO becomes the cable that Tesla has to accept. CHAdeMO is also a lot more prevalent in the US than CCS.
The interesting thing is that CCS comes from the continent that isn't known for making EVs.
Eno Deb
Active Member
But that's really the point of 800V charging: to increase the power without having to increase the current and thus requiring even thicker and more expensive cables.
I'm not a battery expert, but I read somewhere that this is largely a matter of cooling. There is a video on Youtube that shows a Taycan prototype charging at [email protected], so almost 250kW, with a SoC of ~25%. That's already more than twice of what Tesla can currently do. Assuming it can be sustained for a while, cutting down supercharger stops from 40 to 20 minutes would be great progress in my book. Watch from around 18:30:
Eno Deb
Active Member
There are various ways to implement 800V charging. One option is to partition the battery into two cell groups of 400V each, and then use a contactor to switch the pack between a serial (800V) and parallel (400V) configuration.
Cooling matters but there's no way to pull heat out of batteries fast enough past a certain point. Tesla already charges at ~1.5C for the Model 3. Higher C-rates will lower the lifespan of a battery. It's possible they're using some sort of different battery tech that won't degrade even after even higher C-rates, but I'll remain skeptical. 250kW is almost 3C, which is way way higher than what Tesla does. I'm not saying it's not possible, but I am saying it's possible that Porsche is just making the compromise to have the batteries degrade more if supercharged (or whatever).
ℬête Noire
Active Member
Also it would introduce efficiency losses (and thus there would be more heat the shed while charging, too, which again means more $ for extra HVAC capacity or heatsink fins or whatever).
ℬête Noire
Active Member
The only way they could do that is combine it with what VW is doing with the I.D., a bunch of battery capacity on top that they never actually fill. One consequence of that is what they'd end up with the curb weight of a similar function kWh Tesla looking positively lightweight.
EDIT: As a side note has anyone seen a Taycan curb weight spec mentioned anywhere? I didn't watch that video, do they mention it there? I don't speak German, and Youtube is insisting on only Deutsche CC.
I haven't seen one yet, I assume that it hasn't "leaked" means that the Taycan is going to tip the scales pretty high.What Porsche will have done here to allow this sort of rate at all will have been to greatly reduced the volume density of their battery. That means a much higher % of their car's interior volume is taken up with battery pack and accompanying cooling system. I believe that's the battery density trade-off (rather than battery weight density) that Musk meant said he didn't want to make.
Eno Deb
Active Member
Nope, he doesn't mention the curb weight.EDIT: As a side note has anyone seen a Taycan curb weight spec mentioned anywhere? I didn't watch that video, do they mention it there? I don't speak German, and Youtube is insisting on only Deutsche CC.
And that's another point. Going CCS won't help Tesla in China or Japan. It's also not the same plug as used in Europe, Australia or New Zealand, so it won't even provide the logistical benefit of reducing the number of plugs variations used.
Tesla just had a "bad" month in the USA and it still sold 5 times the number of CCS equipped BEVs.
By the time CCS BEV sales match it, Tesla will have even more cars sold, more Supercharger coverage, and more Supercharger density.
The _only_ time Tesla would switch to CCS would be if they find their current plug is inadequate and they want a new design. But then, if they deliver the SR, and continue to get high volume, they could use any design they want.
Similar threads
