Onboard charger: 19.2kw vs 150 kw/400v - which do I need?

[Scandinavian]

example:

• EVSE (external charging hardware) reports to car it can do 16 amps (20 amp breaker)
• EV charger inside the car sees this an understands this but goes ahead and "pulls current" for 32 amps

@daveo4EV , I thought the Porsche Mobile Charger Connect easily could reduce the current supplied to the vehicle? It is one of the menu items. And I also think that the Tesla Wall Connector has some rotary switches that can limit the current? At least that is what I have used to limit the current drain during the nights in winter time. I use a number of heat pumps to heat and store warm water at these times. By reducing both the above EVSE current I have avoided to pull too many amps? Maybe there is a difference in regions ?? It would be scary else since I can draw up to 36 kW on 3 phase supply. And I have seen 32 -34 kW being drawn at times, but then the car chargers have been throttled to about 5 - 6 kW maximum each.

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[daveo4EV]

@daveo4EV , I thought the Porsche Mobile Charger Connect easily could reduce the current supplied to the vehicle? It is one of the menu items. And I also think that the Tesla Wall Connector has some rotary switches that can limit the current? At least that is what I have used to limit the current drain during the nights in winter time. I use a number of heat pumps to heat and store warm water at these times. By reducing both the above EVSE current I have avoided to pull too many amps? Maybe there is a difference in regions ?? It would be scary else since I can draw up to 36 kW on 3 phase supply. And I have seen 32 -34 kW being drawn at times, but then the car chargers have been throttled to about 5 - 6 kW maximum each.

NOTE: to date I have never ever heard/seen/rumored an EV that behaves in this manner and it wold be a serious manufacturer defect if it did and a recall would certainly be in order - this is a hypothetical thought exercise.

please remember the post was a ”thought experiment“ what would happen _IF_ the car “IGNORED” the amp limits reported by the EVSE - to date I’ve never seen a vehicle do that.

I’m simply pointing out that since EVSE’s are mostly just a pass through device - there would be nothing in the EVSE that would prevent the vehicle from pulling more power than the EVSE reports could be pulled.

 

[schad]

The circuit breaker protects the EVSE. It would be redundant and unnecessary to have anything additional in the EVSE, other than possibly a fuse for the control circuit, but this would likely be supplemental overcurrent protection vs branch circuit overcurrent protection (different standards).

This is not correct. The purpose of a circuit breaker is to prevent the wires in the walls from overheating to the point that they can cause a fire. Any other protection offered is incidental to that purpose.

For example, a QO-style Square D 20A breaker will, when subjected to 32A (1.6x rated current), take ~100 seconds to trip. That's plenty of time to release the magic blue smoke of an EVSE that doesn't have its own fuse. The same breaker won't trip in <1 second until ~160A (8x rated current).

Consider the common scenario of a 32A EVSE that is installed on a 50A circuit. You can run 40A on that circuit all day long without ever tripping the home's breaker. But if the EVSE tolerates 40A without breaking the circuit somehow, something will eventually overheat and cause a fire. This is not at all an unimaginable series of events. I can't imagine any reputable testing agency putting their seal on a device where this scenario was only prevented by software on an uncertified device (the car).

I certainly want an EVSE to be engineered such that it will fail-safe in an overcurrent situation. Ideally this would be by a blown fuse or tripped breaker inside the EVSE itself. Failing that, the EVSE should self-destruct in a safe manner that permanently breaks the circuit. Probably most EVSEs use this latter method, but I don't actually know that for sure. Mine was open when the electrician was installing it and I didn't see a fuse anywhere.

 

[Jhenson29]

This is not correct. The purpose of a circuit breaker is to prevent the wires in the walls from overheating to the point that they can cause a fire. Any other protection offered is incidental to that purpose.

For example, a QO-style Square D 20A breaker will, when subjected to 32A (1.6x rated current), take ~100 seconds to trip. That's plenty of time to release the magic blue smoke of an EVSE that doesn't have its own fuse. The same breaker won't trip in <1 second until ~160A (8x rated current).

Consider the common scenario of a 32A EVSE that is installed on a 50A circuit. You can run 40A on that circuit all day long without ever tripping the home's breaker. But if the EVSE tolerates 40A without breaking the circuit somehow, something will eventually overheat and cause a fire. This is not at all an unimaginable series of events. I can't imagine any reputable testing agency putting their seal on a device where this scenario was only prevented by software on an uncertified device (the car).

I certainly want an EVSE to be engineered such that it will fail-safe in an overcurrent situation. Ideally this would be by a blown fuse or tripped breaker inside the EVSE itself. Failing that, the EVSE should self-destruct in a safe manner that permanently breaks the circuit. Probably most EVSEs use this latter method, but I don't actually know that for sure. Mine was open when the electrician was installing it and I didn't see a fuse anywhere.

I’d probably avoid putting blue smoke in your EVSE to start with. Can’t let it out of it isn’t in there. ?

But I think you may have been missing my point that the parts of the EVSE that are affected by the vehicle load are line/load wires and some contacts. What are you gong to put in to protect it that you don’t already have upstream?

I would agree that having a plug-in EVSE that isn’t rated for the maximum current for the receptacle it’s made to plug into is a problem. In that case, I would agree it should have additional OCPD for the vehicle load.

But not generally otherwise.

 

[Mysta]

I think 400v 150kw will be good if Tesla does indeed open up charging. Especially when you consider how much importance Tesla buyers put on 'tesla supercharging network' and the fact that Taycan could likely hold 150kw to 80-90%

 

[daveo4EV]

I think 400v 150kw will be good if Tesla does indeed open up charging. Especially when you consider how much importance Tesla buyers put on 'tesla supercharging network' and the fact that Taycan could likely hold 150kw to 80-90%

no tesla can run a charge at 150 kw fir as long as a Taycan - this will likely expose weaknesses in the current superchargers - also superchargers are a/b split load and shared if 2cars are charging if one gets more than the other until the other one starts to taper - if one car doesn’t taper the slow stall will be stuck with slower speeds for longer than normal - it will be interesting to watch this play out

 

[Mysta]

no tesla can run a charge at 150 kw fir as long as a Taycan - this will likely expose weaknesses in the current superchargers - also superchargers are a/b split load and shared if 2cars are charging if one gets more than the other until the other one starts to taper - if one car doesn’t taper the slow stall will be stuck with slower speeds for longer than normal - it will be interesting to watch this play out

Well they are swapping to v3 fast so in that case it will be funny to see Taycans charging to 80% before Tesla charges to 60

 

[shelt]

I just modified my almost-frozen 4S order to include the 150kW/400VDC charger option. I'm pretty sure Tesla will follow through on opening their chargers, especially after the infrastructure bill. Tesla superchargers are everywhere in California; EA not so much (yet anyway). Seems like a cheap bet relative to everything else on the car...

 

[Jsherid!]

I just modified my almost-frozen 4S order to include the 150kW/400VDC charger option. I'm pretty sure Tesla will follow through on opening their chargers, especially after the infrastructure bill. Tesla superchargers are everywhere in California; EA not so much (yet anyway). Seems like a cheap bet relative to everything else on the car...

I may add a separate thread on this--I just got confirmation from my sales rep (Luke Manning at Grapevine Porsche) that the 400V option is worthwhile if/when Tesla opens their chargers to other brand vehicles.

From: REDACTED, Scott (PCNA-O2) <REDACTED@porsche.us>
Sent: Monday, August 23, 2021 2:50 PM
To: Luke Manning
Subject:RE: Sheridan_ Special Order Deposit Agreement (2).pdf

Well then, I thank you for your patience, sir.

Hypothetically, if Tesla was to open up their Supercharging network to other electric cars, then yes, a Taycan customer would be using the 400V charging capability that’s built into every Taycan.

That being said, if the customer is looking for improved 400V charging performance, then the 150 kW/400V OBC option is a worthy consideration. Being that your customer already acknowledges that it is a relatively low-cost option, I’d implore you to check that box on the build. This would potentially lead to triple the charging performance over the standard 50 KW/400V OBC. This could also benefit the customer at other 400V charging stations (ChargePoint, EVGo, etc.) where their output is greater than 50 kW.

I hope this provides the clarity you’re looking for to inform the customer. Please let me know if you need further support, sir.

Safe travels out there.

 

[Jhenson29]

I may add a separate thread on this--I just got confirmation from my sales rep (Luke Manning at Grapevine Porsche) that the 400V option is worthwhile if/when Tesla opens their chargers to other brand vehicles.

…reread what they said…

Hypothetically, if Tesla was to open up their Supercharging network to other electric cars, then yes, a Taycan customer would be using the 400V charging capability that’s built into every Taycan.

You got confirmation that it uses 400V (which we already knew), not that the option would be useful with super chargers.

The fact is, it will require some kind of adapter and there’s no confirmation the adapter will allow more than 50kW.

It may, it may not. I don’t know.

 

[Jsherid!]

To clarify—the two previous posters are correct there is no guarantee that having this will allow you to charge at 150kW but without it you are definitely limited to 50kW on a 400V charger. For less than $500 on a expensive car I’ll take that bet.

 

[jvincent]

The fact is, it will require some kind of adapter and there’s no confirmation the adapter will allow more than 50kW.

It may, it may not. I don’t know.

I got the same impression. Musk has already said that the non CCS2 Tesla markets (like the US) would use an adapter. There are no adapters currently available that can flow more than about 80kW on a 400V system (200A). They would have to somehow make an adapter that has active cooling to go much higher. Chances of charging at 150kW at a Supercharger? Not good.

EA has had their issues, but I would not bet against their planned growth since every automaker (except Tesla) has hitched their wagon there.

In a pinch, I'd rather endure the wait at a 50kW EV-GO charger than the conversation at a Supercharger.

 

[whitex]

…reread what they said…

You got confirmation that it uses 400V (which we already knew), not that the option would be useful with super chargers.

The fact is, it will require some kind of adapter and there’s no confirmation the adapter will allow more than 50kW.

It may, it may not. I don’t know.

Furthermore this is Elon we are talking about (long time Tesla customer here). Tesla opening the supercharger is likely solely so they can get grants/funding from the infrastructure bill which requires that the network is usable by more then one manufacturer car (actual wording doesn't require more than two). Remember when Elon got grants from the government for developing a battery swap station? He deployed exactly one of those station open limited hours only to people who pre-signed up, but that met the grant qualification criteria. You don't see him talking about battery swapping any more, do you? The supercharger opening could be similar, one adapter available at a few superchargers might meet the minimum criteria to get government grants. The adapter might not be limited, as that might trigger unfair competition accusations, but if there is only one of them and only at a few superchargers, that could happen.

All that said, I still think $460 is worth a gamble here. Even if Tesla limits the adapter availability, there may be people who start making them to sell (just like TeslaTap) and Elon might not want to stop that, if for no other reason than to not have his grant revoked.

 

[Mr. 2021 Taycan]

Lots of interesting opinions and thoughts in this thread. The big question to me is why Porsche doesn't just include the 150kw charging ability in every Taycan as stock. (Hey Porsche, the nickels and dimes get painful not just financially, but as evidence of disrespect for the legitimate needs of your customers.)

This is a very boring video with some good insights into charging about half way through: . Basically, you want the 150kw charging ability if you want access to DC "fast" charging outside the VW 800v network (Electrify America/Ionity). And yes, this will require a 150kw capable adapter for use with the Tesla charging network. Without the 150kw charger in your Taycan you will be able to get a max of 50kw on a 400v DC "fast" charger.

So, presuming the DC "fast" charging network expands (Tesla opens up and other providers), the 150kw charger in the Taycan will offer "fast" charging at many more charging stations outside the VW network. This will take time to mature so buying the 150kw charging functionality now is a bet on the future.

 

[SergeyIndy]

I may add a separate thread on this--I just got confirmation from my sales rep (Luke Manning at Grapevine Porsche) that the 400V option is worthwhile if/when Tesla opens their chargers to other brand vehicles.

From: REDACTED, Scott (PCNA-O2) <REDACTED@porsche.us>
Sent: Monday, August 23, 2021 2:50 PM
To: Luke Manning
Subject:RE: Sheridan_ Special Order Deposit Agreement (2).pdf

Well then, I thank you for your patience, sir.

Hypothetically, if Tesla was to open up their Supercharging network to other electric cars, then yes, a Taycan customer would be using the 400V charging capability that’s built into every Taycan.

That being said, if the customer is looking for improved 400V charging performance, then the 150 kW/400V OBC option is a worthy consideration. Being that your customer already acknowledges that it is a relatively low-cost option, I’d implore you to check that box on the build. This would potentially lead to triple the charging performance over the standard 50 KW/400V OBC. This could also benefit the customer at other 400V charging stations (ChargePoint, EVGo, etc.) where their output is greater than 50 kW.

I hope this provides the clarity you’re looking for to inform the customer. Please let me know if you need further support, sir.

Safe travels out there.

I wanted to see if anyone on the forum has any new information related to availability of 400v/150kW charge points to make use of the optional 150kW upgrade. I added the option to my build totally realizing that chances are of Tesla opening this up are not realistic, still no adapter exists to plug into a 400v to get 150kW, and any new 150kW stations that are going up will be 800v but just out of curiosity if I am looking for one as emergency backup (even if it is a 50kW kind) along my route, what I would be looking for in the search on the map.

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