How many Amps?

[YuO]

Hi all! Excited new B-class owner here!

I talked to our electrician about installing wall charger and he told me we need to know how many Amps we need....Could not find that information anywhere online or in the manual.....Can anyone elaborate?

Also, the cord my car came with only allows 110v....Is it a norm? They dealership told us we can use it for 110-240V and we didn't think to double-check....Just figured it only works with 110V...

thank you!

 

[blaferty]

A 50 amp circuit will accommodate a 40 amp Level 2 charger.
A plug in type Level 2 charger will need a NEMA 14-50P outlet.
This setup will charge your B in about 3.5 - 4 hours from 0% charge.

 

[mddg]

The amperage you would need on the 240V circuit depends on the charger (EVSE) you get. I have a 40A circuit for my 25A charger. If you get a 40A charger, the charger manufacturer will likely recommend a 50A circuit.

 

[JeffRay]

Welcome YuO, you will enjoy the ride.

I only use the supplied cord for 110v top ups at workplace outdoor regular outlets. All commercial or home chargers will come with their own hookup stuff.

Advice for you. Peruse this forum using the search function. It is highly likely that it will be correct vs. whatever a random MB person tells you. Also, check the manual. In our collective experience, with so few of these cars, dealers don't really know. I am one of a few at the Mercedes owned dealership in Manhattan, NY. They still don't know how to charge the car with a hit rate of about 50%. Also, have been waiting two weeks for my VVC number so I can log into the charge monitor app.

 

[YuO]

thank you guys, very helpful!

Yes, our dealership told us that it's the first and only car they sold

 

[GlennD]

The voltage and current depend on the EVSE. The on board Tesla charger can charge at 40A @240V. This requires a 50A circuit and breaker. The stock supplied EVSE uses 120V at 12A. This is 80% of fifteen amps. That is the usual maximum current available. The car is J1772 compliant so the internal charger will match the advertised current, The most common and cheapest EVSE is a 30A 240V unit that requires a 40A circuit. Many have an unused dryer circuit. This will supply 24A (80% of 30A). The car will be happy with it. It will just charge slower.

I just changed cars. I put a longer 30A cable on my EVSE to reach my VW without stretching the cable. So far I am charging my B at 32A. I may in the future change back to a 40A cable. In my case the OpenEVSE will support that with a simple menu change. Many EVSE's are fixed current so putting a 40A cable on a 30A EVSE is a waste of money.

Buying a EVSE that is larger than the car needs is a waste of money. The EVSE tells the car how much current it can supply. If that is greater or equal than the car needs then it takes what it needs and it ignores the rest. If you charged a volt on a 40A EVSE it would take 14A and it would ignore the rest. If it is less than the car's max then it matches the available current.

Except for Tesla derived cars the maximum current is 32A so there is lots of 30A EVSE's out there at cheap prices. Since Tesla's come with a 40A EVSE 40A EVSE's are a specialty device and you pay a lot more. The exception is the basic JuiceBox and the OpenEVSE. Both support the maximum of the installed cables and switching device. On my home constructed OpenEVSE I have a 63A 240V contactor and a 50A range input cable. It can support cables up to 40A.

 

[TonyWilliams]

Your Mercedes uses a Tesla onboard charger with any voltage between 100 and 250 volts.

The max amperage is 40 amps (which can provide 9.6kW @ 240 volts * 40 amps).

I recommend a 50 amp electrical circuit to be installed by your electrician, with a NEMA 14-50R wall outlet / receptacle.

Then, you purchase a portable charging product like this:

http://shop.quickchargepower.com/JESLA-is-THE-40-amp-J1772-portable-charging-solution-JESLA.htm

Or like this wall mounted product:

http://shop.quickchargepower.com/J-Wall-40-the-premium-40-amp-wall-mounted-J1772-charge-station-JWALL40.htm

 

[wtzouris]

If you want a compromise for price/performance, there is a 32 Amp portable EVSE out there by Zencar:

It can use 120v or 240v, and Charges at 10, 16, 24 and 32 Amps. 8-in-1
Most B-Class users use it on 240v/32 Amps setting with a 40 Amp Circuit
It has a 14-50P connector and a long 25 foot cable to J1772.
It is $349 so it allows a lot of extra budget for adaptors, etc, and it is portable.

http://www.ebay.com/itm/122553970958

 

[GlennD]

All of the Chinese chargers that I am aware of work fine. None have GFCI protection and it is a safety item and not required for charging. Most made in the US have GFCI protection and if you claim J1772 compliant it has to be there per the specs. China really has no controls and they can get away with any claim even UL approved. Most US EVSE's are UL approved. The exception is Tesla, The JuiceBox, and the OpenEVSE units but they all otherwise comply.

 

[blaferty]

Juicebox by Electric Motorwerks is now UL Certified.

 

[GlennD]

Juicebox by Electric Motorwerks is now UL Certified.

That is fine if they have a unit that is certified. It is my understanding that something as simple as changing the input cable requires a big buck re-certification. That is the reason that Tesla did not get their design certified. It is a good unit but they did not want to spend the money. Ul certification is a major expense for a small company. For sure it can never be done for a kit like OpenEVSE.

 

[EchoDelta]

FWIW, I have used a NEMA 14-50 with a JESLA since early '15 and couldn't be happier (I had the setup done for a previous PHEV and another EV). (Note the Jdapter was not available when i got it in 2016).
The tesla UMC is a great base EVSE with the swappable adapters, it is great for both home-base and travel backup, and the J1772 makes it compatible with our vehicles even as they change.

 

[GlennD]

I built us two JuiceBox EVSE's and I have had no problems. A while back they were offering the basic parts cheap. Overall I prefer OpenEVSE but the two I sold were reliable. They were very basic. As supplied they had no indicators at all. They seem to be still working since the people I sold them to have not complained.

 

[GlennD]

The Tesla UMC is a great base EVSE with the swappable adapters, it is great for both home-base and travel backup, and the J1772 makes it compatible with our vehicles even as they change.'
''QUOTE"

To me the Tesla EVSE is just too expensive. When you convert it to J1772 Quick Charge Power sells it for 1K. You can easily buy two EVSE's for that money. I also do not like that they use a 30A Pottor and Brumfield relay at 40A. Granted that is the rated non-switching current but what if there is a problem and the relay opens under load?

 

[Calhroub]

Your Mercedes uses a Tesla onboard charger with any voltage between 100 and 250 volts.

The max amperage is 40 amps (which can provide 9.6kW @ 240 volts * 40 amps).

I recommend a 50 amp electrical circuit to be installed by your electrician, with a NEMA 14-50R wall outlet / receptacle.

Then, you purchase a portable charging product like this:

http://shop.quickchargepower.com/JESLA-is-THE-40-amp-J1772-portable-charging-solution-JESLA.htm

Or like this wall mounted product:

http://shop.quickchargepower.com/J-Wall-40-the-premium-40-amp-wall-mounted-J1772-charge-station-JWALL40.htm

Hi. Regarding the maximum current for the US J1772 based B250e:
Do you have any official data or any other proof that 40A is the maximum the B250e can charge on 240V? In Europe the car supports 11kW with 3 phase 16A charging (Type 2 plug). When I tried to plug my car to a single phase 230V 32A charger it only accepted 16A of the available 32A (software issue or differences on-board charger setup?)

Anyways based on the fact that the on-board charger can receive 11kW, isn’t it possible that the the US versions can charge at 48A @ 230V = 11kW?

I would appreciate it if anyone can point me to any documentation. Thanks.

 

[barsaec]

I have a Juicebox 40a charger connected to a 50a circuit in my garage. Charge times are very short.

 

[GlennD]

Your Mercedes uses a Tesla onboard charger with any voltage between 100 and 250 volts.

The max amperage is 40 amps (which can provide 9.6kW @ 240 volts * 40 amps).

I recommend a 50 amp electrical circuit to be installed by your electrician, with a NEMA 14-50R wall outlet / receptacle.

Then, you purchase a portable charging product like this:

http://shop.quickchargepower.com/JESLA-is-THE-40-amp-J1772-portable-charging-solution-JESLA.htm

Or like this wall mounted product:

http://shop.quickchargepower.com/J-Wall-40-the-premium-40-amp-wall-mounted-J1772-charge-station-JWALL40.htm

Hi. Regarding the maximum current for the US J1772 based B250e:
Do you have any official data or any other proof that 40A is the maximum the B250e can charge on 240V? In Europe the car supports 11kW with 3 phase 16A charging (Type 2 plug). When I tried to plug my car to a single phase 230V 32A charger it only accepted 16A of the available 32A (software issue or differences on-board charger setup?)

Anyways based on the fact that the on-board charger can receive 11kW, isn’t it possible that the the US versions can charge at 48A @ 230V = 11kW?

I would appreciate it if anyone can point me to any documentation. Thanks.

My OpenEVSE has a current meter. It usually said 40-41A so the car will charge at 40A@240VAC.

By the way, my 40A EVSE charges my IonIq at 28.5A. If enough current is available the car sets the current. Any excess is ignored.

 

[GlennD]

By the way both of the Mercedes dealers I have measured had 30A EVSE's at 208V. The pilot was set to 30A and that is what you get.

 

[bananapeal]

i am also curious if this car supports over 40 amps. is it true that they shipped different chargers for European version vs US version? has anyone here used the tesla tap? it should allow higher than 40 amps out of a tesla connection!

has anyone seen an 11.1 kw rate in the wild on a well-endowed level 2 station?

 

[hallcp]

The other wrinkle is that 3-phase chargers are common in Europe, but not in the US. You can see extra pins in the European J-1772 connector for 3-phase charging. With 3-phase they can charge faster with the same amperage per phase. [You have now exhausted my understanding of 3-phase electric power. ]