# Forums

## Single vs. Dual Charger theoretical max. charging performance

To clean up some of the misconceptions around the wonders of dual charging I attach a table of the theoretical maximum charging to expect given a certain connection. The connections are the ones you find in "the wild" in Germany. For you own country, assume that single chargers can do 3 phases with 16A max. Or 1 phase with 40. Dual can do 3 phases with 32A max. Or 1 phase with 80A, but I doubt that you will find more than 32A or maybe 40A because of the cables required.

1x230V/16A
Single, Dual 3,7 kW
1x230V/32A
Single, Dual 7,4 kW
3x230V=400V/16A
Single, Dual 6,4 kW
2x230V=400V/32A
Single 6,4 kW, Dual 12,8 kW

Unless anyone proves me wrong that means that dual charging in Germany only has a benefit if you have a 400/32A connection. For everything else, incl. 3 phase 230V/16A, a single charger does exactly the same.

And, none of this numbers is 11 or 22kW.

Cheers!

PaceyWhitter | 10. Juli 2013

I'm sure that Tesla will provide a European spec HPWC that will be able to produce 20kW.

In the US there is also no standard plug that would provide the 240V/80A that the HPWC produces.

RZippel | 11. Juli 2013

The chargers have the following spec:

11 kW: 85-256V, 45-65 Hz, 3Phase 16A or 1Phase-40A (Optional 22kW: 3 Phase 32A and 1-Phase up to 80A)

No matter what Tesla provides with the HPWC, the voltage will be 230 (per phase, or 400 effective for 3) and so the max. charging see above.

230V/80A requires a new link into the house (typically 100A here) and I got a quote for that from my provider, around the cost of the car ;-)

So I don't expect that we will ever see a HPWC for Germany that is more than a nice design replacing the socket because you just don't get anything more than 400V32A and that only requires a 20€ socket you can buy at Amazon...

Btw., my Model S is scheduled for December and I still struggle to upgrade my socket in my garage to 400V/32A... No I have decided that is not an issue, just don't like the wrong expectations.

In my Tesla shop the Tesla guys claimed the cars would already be charging faster than what I calculated, but plugging them in after the test drive produced EXACTLY what I predicted... in this case 1 phase / 32A...

Cheers!

tobi_ger | 11. Juli 2013

RZippel
Are you sure that the test car you plugged in was actually a EU version with 3-phase support?

Brian H | 12. Juli 2013

tobi;
Unless it was a prototype, they didn't exist.

tobi_ger | 12. Juli 2013

Brian H
Exactly why I asked, as RZippel shouldn't have been suprised of the 1 phase / 32A at the time.

tes-s | 12. Juli 2013

Perhaps Germany will have to upgrade their residential electric infrastructure to support home charging of EVs.

tobi_ger | 12. Juli 2013

tes-s
Not needed for "regular" charging (houses have 230V/16A lines here; some have additional, more powerful lines as extras). It's just that the current MSs in Germany basically have the US-chargers, not the ones with 3-phases support.