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Discussion Starter #1
We have a B250e and it's our first EV. When we first bought the car from Mercedes in Solihull, it came with a charger box that you could plug into a standard 3 pin socket at home. Charging time was as expected, around 9 hours for a full charge.

I was under the impression (from many sources) that the B250e could charge at 7kW, bringing the 100% charge time down to ~4 hours.

Mercedes B 250e
Mercedes B250e Electric (2015) Charging Guide | Pod Point
https://www.mobilityhouse.com/int_e...enz/mercedes-benz-b-class-electric-drive.html

Therefore I had a home charge point installed by EVChargers, pulling from a separate 32A spur from the consumer unit.

It's taken us a while to realise that it's still only charging at 3kW. I tried the car in a neighbour's wall box, and again, only 3kW. We also tried a local McDonalds charge point, and still only 3kW. When my wife popped to the local Mercedes dealership and tried their charge point, hey presto 7kW, but from a 3 phase supply.

So, based on the info from those sources I mentioned above, I have had the car checked by Mercedes. They cannot find any faults with the car, and are now claiming that the B250e will ONLY charge at 7kW from a 3 phase supply....

So who is correct? All the 'non-Mercedes' web sites, or the Mercedes technician?

Does anyone else get 7kW from their single phase wall box??

If Mercedes are correct, then I'm disappointed that EVChargers were more than happy to sell me a home charge point, when there's absolutely no benefit in having one for a B250e!

Quick answers would be most appreciated as the car is with Mercedes and I don't want to accept the car back if there's something wrong with it.

Thanks.
 

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The mercedes has three 16A charging modules. This system is common to many Tesla models.

In the USA, these are all wired together, allowing a charge rate up to 40A, or about 10KW. This is because in the USA, three phase supplies arent all that common, and the type 1 charging socket used in the USA is single phase only.

In Europe, these three charger modules are each connected to one phase of the 3 phase type 2 charging connector. Again this is due to the layout of electrical distribution, especially on the mainland, where many countries run three phases to each property, but with much lower maximum current.

Thus when a European B250e is connected to a single phase supply, only one charger is powered, and the car only charges at 16A. If its connected to three phase supply, you'll actually get an 11kw charge rate, and it'll charge the car in about 3 hours.

The really odd thing, is that in a Tesla equipped with this system, it somehow automatically switches the charger configuration, such that it CAN charge at 7kw on a single phase supply. I presume whatever additional relays/contactors are required to achieve this, are missing on the B250e implementation.

A few people have experimented by modifying the charge cable to supply a single phase to two of the three phases in the connector, and the car does accept this and charge at 7kw, however this is seriously non standard and extremely dangerous if someone were to use that modified lead on another EV.
 

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If Mercedes are correct, then I'm disappointed that EVChargers were more than happy to sell me a home charge point, when there's absolutely no benefit in having one for a B250e!
Also, even stuck at 16A, its still a good bit faster than charging with a granny lead, not to mention safer. Plus you've got a charger that CAN do 32A for whenever you get your next EV at some point down the line.
 

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We got a 7kW charger fitted on the OLEV grant when we had B250e for 7 months. We knew it would only charge at 3.3kW but that was still a lot faster and safer than the granny at 2.3kW. Getting 7kW was to be future proof for a "proper" Type 2 EV ;)

Despite the stupid charging, short range and breaking down once, we thought the B250e was OK. In terms of local driving, we both prefer it to the i3 we currently have but the i3 120Ah does make long journeys viable :)

Incidentally (being mad) we actually did do a couple of long journeys in the B250e to use up some of the lease miles. We charged at 11kW on 22kW posts including the free EH one at Leicester MSA and used a Polar Rapid in Milton Keynes. Normally I would "tut tut" at sipping 11kW from a Rapid, but they arent exactly scarce in MK :D
 
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Forgive my ignorance but what's EH at Leicester MSA.

As for Polar, I signed up for it for the free 3 months, but when it came to pay for the 4th month I cancelled as I'd never used one in those first 3 months. Having an ICE car as well as the BEV, we never use the BEV for any longer journeys.
 

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Forgive my ignorance but what's EH at Leicester MSA.

As for Polar, I signed up for it for the free 3 months, but when it came to pay for the 4th month I cancelled as I'd never used one in those first 3 months. Having an ICE car as well as the BEV, we never use the BEV for any longer journeys.
Ecotricity has sixteen 22kw AC free posts, mainly at service stations, however we tried to use the Michaelwood a couple of times recently but it had no power. You have to register for a RFID card from this page https://www.ecotricity.co.uk/for-the-road/charge-your-vehicle/ac-medium/registration-form which will allow you to start charging. You need your own cable.

The list of where they are is here: How to charge your car
 

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Forgive my ignorance but what's EH at Leicester MSA.

As for Polar, I signed up for it for the free 3 months, but when it came to pay for the 4th month I cancelled as I'd never used one in those first 3 months. Having an ICE car as well as the BEV, we never use the BEV for any longer journeys.
EH electric highway, i.e. Ecotricity
MSA motorway service area.
Common parlance around these parts.
 
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Maximum charge rates for B250e

-Granny charger/3-pin plug ~2.4kW
-Single phase wall/public charger 3.6kW
-Three phase charger 11kW (normally advertised as 22kW AC chargers with 2 available sockets)
-AC head of rapid 11kW (emergency use only...)

Typical range:

-summer 80-100 miles
-winter 55-70 miles*
(this is sub-70mph and driven sensibly - reduce accordingly if you're beefing it or fast motorway)

Add 10-15% if you charge with with extra range mode (assuming car has it)

*Every start from very cold will eat about an extra 2-3kWh within the first 10 miles heating the cabin and battery pack, so a commute range with no charging during the day may be as little as 50 miles total in sub-freezing weather.
 
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