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Discussion Starter · #1 ·
Hi,
I bought my car 1 month ago and has never been able to charge the battery above approx. 330 km.
If I set maximum charge level in Mercedes ME app to 80% I am able to charge to about 270km.
If I set maximum charge level in Mercedes ME app to 100% I am able to charge to about 330km.

I have talked to many MB dealers and all says this depends on my driving pattern.
This does not make sense for me, the charging level has never been higher than 330km from day 1.

Someone with same experience?
Is it something wrong with my battery?

Best regards,
Per Kristiansen
 

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What does your trip meter report with regards average consumption?

The displayed range calculation goes something like this:

Range = 80 * SoH * SoC / recent_consumption * 100

where
SoH is State of Health - indicates how tired your battery is getting
SoC is State of Charge - how high you've charged it (80%, 100% etc)
recent_consumption - average consumption rate over the last recent(*) usage in kWh/100km

(*) - as far as I know nobody knows how "recent" is defined, but my guess is it's over the last 100 or 200 kms (somewhere around there).

So there's actually two numbers in that equation that the onboard computer knows but doesn't share with us: SoH and recent_consumption. You can get an approximation of recent_consumption by using the "From Reset" trip meter. I reset mine each time I charge, and I often charge roughly ever 200 kms (give or take).

So, enough algebra - let's plug in some numbers to make it real. Let's assume your SoH is still 100% since your car is new, and let's assume your recent_consumption is 23.7 kWh/100km and that you've charged the battery to 80%:

Range = 80 * 100% * 80% / 23.7 * 100
= 270km.

So it really is the consumption number you need to focus on, not the indicated range. As the dealers mentioned that varies wildly with driving patterns (city traffic Vs high speed Euro motorways), weather, ambient temperature, wheel size, tyre pressure, roof racks, running boards etc. etc.
 

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Or for another scenario, imagine you bought a second hand EQC and the battery is down to 85% of its original capacity, but you got one with 20" wheels, runner boards and no roof racks. Most of your motoring is around town, you run the tyres fairly hard and live in a sub-tropical climate. And let's assume all of that results in a consumption of 20.1 kWh/100km.

Range = 80 * 85% * 80% / 20.1 * 100
= 270km.

Both scenarios result in the same range you're seeing - one with a pristine battery, the other with a battery that's starting to age.
 

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Hi,
I bought my car 1 month ago and has never been able to charge the battery above approx. 330 km.
If I set maximum charge level in Mercedes ME app to 80% I am able to charge to about 270km.
If I set maximum charge level in Mercedes ME app to 100% I am able to charge to about 330km.

I have talked to many MB dealers and all says this depends on my driving pattern.
This does not make sense for me, the charging level has never been higher than 330km from day 1.

Someone with same experience?
Is it something wrong with my battery?

Best regards,
Per Kristiansen
I have written numerous posts on several EV forums on this topic. There is nothing wrong with the car rather it is a misunderstanding of the realtionship between range in khw per km and the amount of energy that requires from that available in the battery for the given SOC. So when you charge you out x kwh in the battery up to a max of 80.
how far that will gin km depend on your efficiency or consumption per km which in turn depends on driving style, geography and traffic conditions and temperatures etc.
I am not able to write in more detail currently but will try to locate a previous posting which discusses this at length.
 

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Discussion Starter · #5 ·
What does your trip meter report with regards average consumption?

The displayed range calculation goes something like this:

Range = 80 * SoH * SoC / recent_consumption * 100

where
SoH is State of Health - indicates how tired your battery is getting
SoC is State of Charge - how high you've charged it (80%, 100% etc)
recent_consumption - average consumption rate over the last recent(*) usage in kWh/100km

(*) - as far as I know nobody knows how "recent" is defined, but my guess is it's over the last 100 or 200 kms (somewhere around there).

So there's actually two numbers in that equation that the onboard computer knows but doesn't share with us: SoH and recent_consumption. You can get an approximation of recent_consumption by using the "From Reset" trip meter. I reset mine each time I charge, and I often charge roughly ever 200 kms (give or take).

So, enough algebra - let's plug in some numbers to make it real. Let's assume your SoH is still 100% since your car is new, and let's assume your recent_consumption is 23.7 kWh/100km and that you've charged the battery to 80%:

Range = 80 * 100% * 80% / 23.7 * 100
= 270km.

So it really is the consumption number you need to focus on, not the indicated range. As the dealers mentioned that varies wildly with driving patterns (city traffic Vs high speed Euro motorways), weather, ambient temperature, wheel size, tyre pressure, roof racks, running boards etc. etc.
Hello,
thank you for detailed description.

Last average consumption is 27,8kWh / 100 km.
What is the first digit: "80" in your calculation based on?

I bought my EQC 1 month ago, the car was driven 8500 km, I can't understand that battery health shall be bad.

When I charged for the first time max. charge level become 320km (Mercedes says teoretically 410km), - the car had no driving pattern from my side, was it based on the earlier owners driving?
Why is it not possible to reset driving history totally and charge to a higher level?
This is incomprehensible for me, I can understand that range will vary depending of driving pattern, but I can't understand why it is not possible to charge a car never used before
to a higher charge level.


I
 

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Discussion Starter · #6 ·
I have written numerous posts on several EV forums on this topic. There is nothing wrong with the car rather it is a misunderstanding of the realtionship between range in khw per km and the amount of energy that requires from that available in the battery for the given SOC. So when you charge you out x kwh in the battery up to a max of 80.
how far that will gin km depend on your efficiency or consumption per km which in turn depends on driving style, geography and traffic conditions and temperatures etc.
I am not able to write in more detail currently but will try to locate a previous posting which discusses this at length.
Thanks for your answer, see my comments in other post too.
My big question is why was is not possible to charge my EQC to a higher level the first time I used it?
 

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Last average consumption is 27,8kWh / 100 km.
That's pretty high and I think explains the low range numbers you're seeing.

What is the first digit: "80" in your calculation based on?
That's the quoted usable battery capacity in kWh (the size of the tank, if you will).

I can't understand that battery health shall be bad.
Judging by the numbers you've quoted, I'd say your battery is very healthy.
 

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(oops.. hit post reply before I intended)

the car had no driving pattern from my side, was it based on the earlier owners driving?
It's based on the most recent 100 (maybe 200?) kms driving. It has no concept of ownership.

I can't understand why it is not possible to charge a car never used before
to a higher charge level.
I think you might be confusing "charge level" and "range". I'm sure it's charging the battery to the level you request (80%, 100% etc.). The range it then displays is based on the formula above. Given it ages it out over a hundred or so kms, the previous owner's history is long forgotten.
 

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Thanks for your answer, see my comments in other post too.
My big question is why was is not possible to charge my EQC to a higher level the first time I used it?
Cannot easily find previous postings sorry.
You need to find the 2 trip meter figures, the from reset which will show the average consumption over a long period in my case 22.8kwh/100km over 13967km.
The from start is your last journey/journey over the previous 4 hrs of driving and mine from today is 20 .5 kWh/100km.
I charged to 50% this evening and the range is shown as 195km. X 2 becomes 390km fully charged.
So to have a range of 195km at 50% SOC means the car expects an efficiency of 20.50kwh/100km which is the efficiency I achieved today.
When you charge you do not put x km of range in the car you put in x kWh of energy which dependent on all the conditions of driving will deliver x no of km.
So looking at your stats the car seems to think it will be used at 25kwh/100km. The range on the WLTP tests are 361 to 420km ie 22.16.kwh/100km to 19.04kwh/100km but that is best scenario WLTP the real world is different.
I use the Mercedes’ eco coach app well worth downloading if in your country and that shows over the last 5 days my consumption was 21.6kwh/100km but the group average ie all those who subscribe is 23.8kwh/100km. From that you can see I am within the WLTP figures but the group average is not so some must be well above. If I make short journeys mainly uphill I will def have much worse efficiency.
coming back to your issue you can reset figure from reset from the onboard computer or the app but you will see the average consumption it is showing and when it started ie for the full mileage of the car or from a recent reset. Also look at the last trip data from your last journey this will then let you see how it relates to the suggested 25kwh consumption. Also check the consumption as you drive using the on board computer it is possible to have a display of consumption since start check the manual it will tell you how to do this.
if the car says your consumption is lower then you may be able to make some judgement on the state of health of the battery but beware as the car starts taking into account your driving the range may actually adjust. also be aware the car excludes power used for heating etc so there is some minor discrepancy. Using the EQ button you can see from the consumption screen how much the ancillaries and the heating etc use sometimes it is little sometimes a lot.
I really recommend you download the Mercedes’ eco coach app as it helps a lot to monitor consumption, battery care etc and you can earn points to offset charging costs or carbon.
I doubt there is anything wrong with your car, it is merely the way the car like all BEVhas been sold has left a confusion as to what it means in relation to max range at a full charge. We would have the same issue with ICE had they been soL d in the same way but they were sold on the litres per 100km figure not range!
am happy to clarify anything if it is not clear😉
 

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Forgot to say the max available battery charge is 80kwh so if I achieve 20.5kwh/100km that is 80kwh/20.5kwh = 3.95 x 100 = 395 km
To achieve 410km with an 80kwh battery means an efficiency of 80kwh/410= .1951x 100 = 19.51kwh/100km and in summer on the right journey I have indeed surpassed that figure of efficiency!
it is complicated but not once you understand the concept and realise it is no different to a petrol or diesel car. Sadly the way the cars are sold has mislead people to think the actual range is a guaranteed figure dependent on the no of kwh in the battery which of course it is not anymore than the no of litres of petrol guarantees a specific range something we all understand.
Eventually like me you will be comfortable knowing how much range you have from your consumption or anticipated consumption on that journey dependent on speed temp etc.
 

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Discussion Starter · #11 ·
Forgot to say the max available battery charge is 80kwh so if I achieve 20.5kwh/100km that is 80kwh/20.5kwh = 3.95 x 100 = 395 km
To achieve 410km with an 80kwh battery means an efficiency of 80kwh/410= .1951x 100 = 19.51kwh/100km and in summer on the right journey I have indeed surpassed that figure of efficiency!
it is complicated but not once you understand the concept and realise it is no different to a petrol or diesel car. Sadly the way the cars are sold has mislead people to think the actual range is a guaranteed figure dependent on the no of kwh in the battery which of course it is not anymore than the no of litres of petrol guarantees a specific range something we all understand.
Eventually like me you will be comfortable knowing how much range you have from your consumption or anticipated consumption on that journey dependent on speed temp etc.
Thank you for good explanation.
So my biggest "problem" is perhaps that I mostly do short driving tours mostly that result in this high consumption?
Good advices for bringing this down?
I don't think my driving pattern is very uneconomical, and I am a careful driver (no kick downs or hard driving).
I normally drive in "Comfort" mode, will it make big difference to mostly use "Economic" or "Fuel saving" ?
 

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A good starting point is the Consumption screen to at least determine where the energy is going. On very short trips you might find a lot of it is going into overheads like charging the 12V battery and cooling or heating the cabin. Yesterday I did a 76km trip all at sea level, mostly 110km/hr on the motorway, with some slow urban stuff at each end. The ambient temperature was 32C for most of the trip, the cabin temp was set to 22C and the seat cooler was on.

Gauge Personal luxury car Font Auto part Speedometer


Automotive design Car Vehicle Speedometer Gauge


The air-conditioning is impressively efficient and effective once things have settled down. But had I taken a snapshot just 5 minutes into the journey, way more (as a percentage) would have been lost to charging the 12V battery (Other Instruments) and cooling down the cabin. So if all your journeys are 5 minute journeys it can have a big overall impact.
 

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And incidentally, had I maintained that average for another 100kms or so, and then filled it up, I'd expect the range to show 437km (80 / 18.3 * 100).

Alas, by the time I returned home and did some other running around it's now climbed to 20.5 kWh/100km - I suspect I had a slight tail wind on the way out, which turned into a slight headwind on the return. If I filled up now I'd expect the range to show 390km (80 / 20.5 * 100).

If I had consumption similar to your 27.8 kWh/100km I'd expect a full tank range of 288km (80 / 27.8 * 100).

All those calculations assume a battery SOH of 100%. At 18 months, and 28K kms my battery is probably a little less than that now, i.e. it's full capacity is probably a little less than 80kWh, although not enough for me to notice.
 

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By way of comparison, here's a short trip today under virtually identical conditions and settings as yesterday's trip:

Font Auto part Circle Science Space
Sky Font Science Audio equipment Technology


Only 77% of that energy was going into moving the car, compared to yesterday's 92%.

If I just did trips like that for a couple of hundred kms, and then filled up, I'd expect the range to indicate 280km (80 / 28.6 * 100).

I hardly ever exclusively do tiny trips like that (average since new is 20.6 kWh/100km) but even if I did, the range wouldn't bother me so much - it would just mean plugging in every 4th day instead of every 5th. I only care about range when I'm doing long distances and in that case I consistently get about 380km from a full tank. That's probably helped by our sub-tropical climate and strictly enforced 110km/hr speed limit on motorways. It's seems the consumption difference between 110km/hr and 130km/hr is pretty significant.
 

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I had to do a double take on the consumption screen shot as it all looked back to front to me as of course I have a LHD and you have a RHD and Mercedes’ have turned the screen so the displays are in the âme order ie other consumption is furthest away.
I always drive in comfort, air con on and always in dauto so the car and I use the limiter to make sure I do not break the speed limits a habit I adopted when I was applying for nationality here (since granted) as I thought having anything registered with the police was not a good idea!
With dauto the car will glide a lot ie use no power. Have a look at the energy flow screen as this shows if the car is using power, gaining power via regen and also if it is 2 or 4 drive. It is quite impressive how the car is changing all the time but it does help inform you how to get the best economy. I do not drive specifically to obtain good economy so I will overtake and always go to the max speed limit (obvioulsy if appropriate) but I drive in particularly friendly conditions for achieving good efficiency. Short journeys will indeed mean the range shown will be reduced BUT that does not mean you will not get more range on the day you go on a longer journey and you see a much better consumption figure as you progress. The range does update as you are driving so you will see it reduce less the lower your consumption goes and indeed on some journeys I see km added as I am gliding and using less power but a steep hill will see them reduce.
Spend a little time taking note of what is happening and you will get a feel for it all and it will become instinctive to know the sort of range you will achieve and how much battery % you may need for a given journey. also the intelligent navigation will plan a route and tell you when you need to inc charging.
hope this helps
 

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Thank you for good explanation.
So my biggest "problem" is perhaps that I mostly do short driving tours mostly that result in this high consumption?
Good advices for bringing this down?
I don't think my driving pattern is very uneconomical, and I am a careful driver (no kick downs or hard driving).
I normally drive in "Comfort" mode, will it make big difference to mostly use "Economic" or "Fuel saving" ?
Sorry forgot to say I have never used economic I tried it but it seemed odd.
 
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