[ThatPhilBrettGuy]

I 'think' I can guess the answer and apologies if this has been covered before/well known. But anyway :-

Just got a new Mercedes 300DE. Love the car and went in with my eyes open about what the real electric range would be, so all good there. It's the charging that's a bit odd. With the supplied Type 2 to Type 2 cable tried a couple of 7.2kw points that comments show (off ZapMap) that 7.2kw was possible. 3.6kw on both. Noted that the connector mentions 20A.

So they've given me what I assume is a cable that can only do 3.6kw. So, off to a local Mercedes garage and they were very good, confirmed it was the usual cable supplied with the car and tested it on their point....7.2kw.

So how and why? Is it that the Mercedes point is 3 phase and the others only single phase? And the crucial question, if I buy a 32A Type 2 cable will that open up more 7.2kw points?

Thanks for any help!

 

[dk6780]

You have answered your own question. The 3P+N+E means three phase, but with each being limited to 20 amps. In reality the 330DE will only use two phases, each at 3.7kW, hence the 7.4kW rating of the car. If you use a 32 amp single phase cable it will also charge at 7.4kW.
You will find more charge points in the UK capable of charging at 32 amps single phase than you will 3 phase.

 

[HandyAndy]

Interesting! Googling this Ev gets me this info:

and the label on your Mennekes deffo shows a 3-phase 20A device. 20A is actually the current rating for the wire used in 16A Type-2 cables. I'd say your dealer was charging using a 3-phase EVSE, and I'd expect that cable to only give you 3.3 kW when used on a UK single-phase 7 kW EVSE. And I think that using a full 32A single phase cable would get you the full 7 kW. I'd have a chat with your dealer about these details - they ought to know what they're selling! I think your analysis is absolutely correct.

 

[ThatPhilBrettGuy]

You will find more charge points in the UK capable of charging at 32 amps single phase than you will 3 phase.

Thanks, my straw poll of 2 suggests you're right.

And I think that using a full 32A single phase cable would get you the full 7 kW. I'd have a chat with your dealer about these details - they ought to know what they're selling! I think your analysis is absolutely correct.

Yup, although dealers knowing their product? I definitely get the impression that it's all a bit new to most of them and as soon as you exhaust their 1 days training you're on your own. As usual I'm sure there's someone in the company that knows the actual answer, but getting to them is hard.

For example, regen. There's a meter that shows you the regen amount. Now, when you get to the end of the scale are you then into mechanical braking? Not expecting an answer here, just an example of the gaps.

Maybe I'm odd and 99% of people don't care and just drive...

 

[MarkAlexHarris]

Speaking as a Mercedes owner (and rating them as one of the best customer service organisations for passenger cars that I have ever dealt with) I can confirm that the expertise exists but is often so deeply buried in the organisation (in Germany) that it takes months to find the answer to any technical question of any complexity

 

[Spiny]

It would be worth plugging into a 11kW or 22kW post with the 3phase cable as some cars actually have 3 off 16A chargers and switch to using 2 with a 32A single phase cable.
If may be like the 3 phase pug 208 and charge at 11kW on 3 phase which would be a nice bonus.

 

[dk6780]

99% of people don't care and just drive...

That's exactly it. Hence they can get away with employing vacuous suits in the dealership who provide whatever the current fashion is. For the vast majority of punters they don't need to know and are one step ahead in their knowledge. When they meet someone who knows or is interested it is just too hard and they move on to the next easy sale.

 

[dk6780]

It would be worth plugging into a 11kW or 22kW post with the 3phase cable as some cars actually have 3 off 16A chargers and switch to using 2 with a 32A single phase cable.

Don't forget that this is a PHEV with only 13.5kWh of battery capacity, so the bean counters in Stuttgart have only allowed two charging units not three. The engineers have deployed them as efficiently as possible to allow them to work to their max on either the 7kW single phase or the more common at home on the continent than here 11kW 3 phase.

 

[Spiny]

Don't forget that this is a PHEV with only 13.5kWh of battery capacity

I'd love to have even 7kW charging with my 10.2kWh PHEV.
Seems a shame as faster charging might encourage more people to actually charge these and drive an extra mile or 2 on electrons.

 

[dk6780]

as faster charging might encourage more people to actually charge these

Wishful thinking when in the main they can't even be bothered to plug them in overnight at home when they get a hugely subsidised charge point.
Moving my thinking on, perhaps OLEV should ask for their money back if the unit isn't used for say three days a week.

 

[ThatPhilBrettGuy]

Just an update. Bought a 32A cable and went off to the local Pod Point. Original Mercedes supplied cable - 3.7kw, new cable - 7.2kw.

So as we all thought really. It's a shame as it would mean that anyone putting a home charger in is going to be slow charging. Probably not a great issue as the battery would fill up over night, but for on the go charging, generally....disappointment.

As dk6780 says, bean counting most likely.

But all sorted and now plugging in when out and about is even more worth it. I agree Spiny faster charging was one of the reasons I like the Merc. Apart from Range Rover P400E's most PHEVs seem to be 3.7kw max. Stupid really.

 

[dk6780]

So as usual the dealership missed the point - the supplied cable only works properly on 3 phase which few homes have and even fewer public charge points support. Clearly neither the dealership nor MB UK understand what is required in the UK - despite the engineers in Germany having gone out of their way to produce an elegant and flexible solution.

 

[HandyAndy]

I'd be inclined to raise this with the Merc dealer, if at all possible. Suggest you go carefully through whatever the glossy brochure for the car states, also what's on their website. That chart I posted above clearly shows a nice piccy of Merc cable, about to be plugged in, and teh table states 1-phase 32A gets you 7.4kW charging. The clear implication is, that given a 7kW EVSE single phase, you simply plug in and get 7kW charging. But, is this a Merc-sourced doc?

If their docs do nothing to dispel this belief, i.e. there are no asterisked weasel-words or similar around, then I think you have a good case to pursue them for a 32A cable. If you can win that case, it would be a brilliant precedent for Merc to up their game properly, and for other EV mfrs to take note. It's unacceptable to assume a Continental solution is suitable for UK market.

Of course, they might respond by trying to provide a single-phase cable with 32A rate but only 1 phase wired in, so 2 fewer conductors than a 3-phase, but again that chart suggests to me that you must be capable of 3-phase charging, where the EVSE offers it. So they shouldn't get away with a kluge like this, if they try it.

If they cave in, and give you a proper 32A 3-phase cable, then you can flog the one you (I assume) bought!

 

[ThatPhilBrettGuy]

Yeah, I'd already been down the specs route and it only every says 7.4kw, not how. The dealer is contacting Germany to see what they have to say...not holding my breath but let's see. They're rare in the PHEV world giving away a type 2-2 cable anyway so in some ways I'm no worse off than most. The dealer themselves have been good and I'd buy off them again. The price was amazing...

The car itself I love. Quiet, comfortable and being the estate great for carrying stuff even with the battery lump. A few shortish trips out and about in Plymouth over the last few days and the diesel didn't kick in once. I'm doing something right anyway!

 

[dk6780]

It might be considered unreasonable not to specify that 7.4 is only available on 3 phase using the supplied lead given that 90% plus of UK charge points are single phase. But if you are happy then that is the main thing.

 

[ThatPhilBrettGuy]

It might be considered unreasonable not to specify that 7.4 is only available on 3 phase using the supplied lead given that 90% plus of UK charge points are single phase. But if you are happy then that is the main thing.

It's the age old issue of detail isn't it. You can charge at rate X....unless Y and Z and etc etc. The EV community seems generally aware of what charging rates can and cannot be, for example if it's roasting hot. But when the masses have to deal with this...hhmmm lots of education needed and the cars saying in plain English (or languages are available ;-) ) what it's doing and why.

Yes I'm happy with the car, mostly as it's exactly what I expected it to be. I knew what the range would probably be and why so that's all good, and on the long journeys we do have the option of old fashioned mode and 600 miles range....

 

[cah197]

Some of use charge at 20 amps or less at home and have much larger batteries.

3.5 kW at home with a PHEV really shouldn’t be an issue.

 

[chrchri91]

Hi, I've a GLC 300e and the same question : how work the 7,4KW charging with 2 phases.
The cable is 20A max. When I plug it on a 3 phases chargeur (22KW), it charge at 7,4KW.
When I plug it on a 1 phase chargeur (7,4KW), it charge at 3,7 KW.
I've got a other cable 32A with 3 phases, and it is exactly the same (3,7KW with 1 phase).

So there is 2 possibles options for the 7,4KW charging on 3 phases charger :

• it uses 400V (between the 2 phases it has) with 18,5A (400 x 18,5 = 7400).
• it uses the double phase-N 230V with 16A each, so 2 x 230 x 16 = 7400.

The problem with the second option : threre is 32A (2x16) in the N cable.

 

[Chickster]

I would ask Mercedes to reimburse you the cost of your new cable.

 

[Ralkbirdy]

3 phase are at different phases, so 3 x16A does not give 48A, as some are positive and some negative, and one probably neutral at different moments.