Mercedes-Benz B-Class ED Battery Larger Than Expected – 36 kWh, 104 Miles Of Range Available

JUN 23 2014 BY JAY COLE 59

Mercedes Benz B-Class ED Battery (now known to be 36 kWh in capacity) Is Readied For Installation In Germany

Mercedes Benz B-Class ED Battery (now known to be 36 kWh in capacity) Is Readied For Installation In Germany

A few days ago we noted that the Mercedes-Benz B-Class Electric Drive online configurator was now online for America.  This meant that US customers could now build and price their own customized plug-in Mercedes.

As part of that, our earlier story speculating that the electric B-Class would have an option for more range was realized.  Specifically, an additional 17 miles of range was available to be had…well, for $600 more anyway.

Amongst the community, the conversation immediately became “how was the extra 17 miles achieved?”  Was it strictly through conservation methods, or was it allowing a greater depth of discharge inside the battery, which had been declared to be 28 kWh by Mercedes earlier?

The answer? Neither.

Mercedes-Benz Describes B-Class Electric Drive Range Package

Mercedes-Benz Describes B-Class Electric Drive Range Package

According to Terry Wei in the Mercedes-Benz USA product and technology communications department in a statement to AutoBlogGreen, while other manufacturers quote the total battery capacity of their vehicles (for example 16.5 kWh in the Chevrolet Volt, 24 kWh in the Nissan LEAF), Mercedes had only quoted the usable amount of capacity to the driver in their specs.

The B-Class ED Is Expected To Hit US Dealerships Next Month - Now With 87 Mile EPA Range Rating

The B-Class ED Is Expected To Hit US Dealerships Next Month – Now With 87 Mile EPA Range Rating

In reality the Mercedes-Benz B-Class ED has a 36 kWh pack.

In ‘normal use’, or for those without the $600 optional range package, just 77% (28 kWh) of the battery can be used during a daily drive.

Considering an EPA range rating of 87 miles (previously thought to be 85 miles), the extra 17 mile package means up to an additional 5.5 kWh is made available (less enhanced efficiencies), for a total of up to 33.5 kWh put in play – or 93%, which gives the all-electric B-Class a true 104 mile range.

Those 104 electric miles are 23 greater than its main competition from BMW in the form of the all-electric i3 (81 miles), and 32 more miles than is found in the BMW i3 REx – which has a 72 mile EPA rating.

As for why Mercedes decided to give the car a stated 87 mile EPA rating and stress using the ‘extended range’ mode sparingly in their literature, Wei says that it was because Mercedes didn’t think most would need it…and that those ‘extra’ miles available in the $600 package will fade over time with use.

“Eighty-seven miles is plenty for your average EV driver, but when you want to have 100+ in the tank, you can. It will take an extra 1.5 to two hours to charge to the new “full” on an EVSE with between 24-40 amps. Basically what you are doing is using, early in life, any excess capacity in the battery.”

The Mercedes rep also spoke a bit on prudent usage of the extra miles, as noted the disclaimer to “only be used on a limited basis”.

“We don’t recommend that folks do this all the time, and we can’t really make a suggestion as to how often,” the rep added, but AutoBlogGreen got the impression that it sounded like using the feature even once a week would not be all that damaging to the battery pack, and figures the $600 is well spend.

We would agree.


Categories: Mercedes


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59 Comments on "Mercedes-Benz B-Class ED Battery Larger Than Expected – 36 kWh, 104 Miles Of Range Available"

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Put a quick charger in it, and I buy it!

better lease it, its german.

Huh? Whats the story behind this?

In the US, German cars have a reputation of having exorbitant repair costs after the warranty expires.

Dr. Kenneth Noisewater

Parts and labor on modern German vehicles are expensive, and they require lots of them, particularly out of warranty.

This makes the B-class ED much more attractive to me — range similar to the Rav4 EV, but in a far more desirable package, and in what I hope is not simply a compliance vehicle. I think it is clever to hide battery degradation in this additional 5.5 kWh of capacity, so that the base range is maintained for what one might hope is the lifetime of the vehicle. Since this is a Tesla pack, can we assume that degradation will be similar to what Model S folks are seeing, which is very little so far?

Well folks, what’s your take then?

A MB ED with 100+ mile range and the looks of a “regular car” or a BMW i3 with an REx and suicide doors?? 😉

I guess it will come down to the fact that some people are BMW people, and some are MB people. But for the many of us who just want a decent EV, BMW sure looks like they have trouble on their hands.

This is just weird. Is MB that confused about how important range is that they have to resort to this “button” crap??? That they have to obscure the true SOC?? Why bother at all? Just use the 33.5 KWH and give the user a way to control the amount of charge. It kind of reminds of the old VW beetle reserve gas thingy. That went away because people are smart enough to figure these things out.

Look at how the gold standard EV goes. No confusion about how much you are charging. No obfuscation of the SOC.

gold standard == Model S

If you charge an electric battery to 100% full regularly then you damage the long term life of the battery. It’s the same on a mobile phone. So batteries normally charge to about 95% and they call that 100% full. This means the end user doesn’t over charge the battery. They are saying it won’t hurt to over charge the batteries sometimes to they let you over charge it with a button that allows a 1-off over charge of the battery.

So why is it that MB can only get 87 EPA miles out of 28 kWh *usable*, while Nissan can get 84 EPA miles out of 24 kWh *total*? Is the MB really 20-25% less efficient?

I assume the MB B-Class has a much higher curb weight than the Leaf.

Curb weight:
B-Class ED: 3,858 lbs
Leaf: 3,326 lbs
i3: 2,635 (BEV) / 2,899 (REx) lbs

It’s no coincidence that this is also the order of efficiency. It will be interesting to see the official MPGe numbers, but I bet the B-Class ED will be one of the least efficient EVs on the market. Light-weighting is one of the keys to get good range without requiring a heavy monster of a battery.

Actually, I think that efficiency tracks CdA and coasting ability more directly than it does weight.

Well, in this case opposite is true: The B-Class has a better CdA (0.59) than both the Leaf (0.65) and the i3 (0.69). So the car with the worst CdA out of the three has the best efficiency. 😉

Remember that drag only make a big difference at higher speeds, which is not the typical driving condition for EVs today.

But it is at higher speeds where I care more about range. A cab driver or pizza delivery guy may spend several hours driving at low speeds, but when I need range, it is invariably because I am going somewhere on the freeway.

CdA matters but so does curb weight. The heavier car takes more energy to get to a given velocity than a lighter car. Even aggressive regen only recovers some of that energy. Bu

Rolling resistance is also a factor and those skinny i3 rutt-catchers make a difference.

I agree with Neal. The i-MiEV weighs less than the i3 but is less efficient. The i-MiEV is NOT a very aerodynamic vehicle.

At what DOD does the Leaf operate, is your question. Mercedes evidently did what Chevy did, which is to give folks a battery and extend its cycle life by conventionally allowing a minimal discharge (77% MB, 65% Volt). The Tesla uses up to ~90%, to get 265 miles (the EPA rating), but otherwise isn’t typically charging to deliver those miles. All these figures have NOTHING to do with efficiency. They help battery LIFE.

Efficiency = Miles / (DOD% X kwh storage), not simply Miles / kwh.

The MB then = 3.1mi/kwh, or 32kwh/100miles if you are a kludgey EPA sticker.

This is big news! Kudos Mercedes.

Its the winter months that matter, and this news puts 70+ miles in the bag. The thick pack shape will be a plus, for heated garages.

I look forward to the 2015 ‘winter comparo’.

I recall someone mentioning extended range last July. 😉

Mercedes is charging a $600 premium to switch on an extended range feature that both the Tesla Model S and RAV4 EV already have as standard.

I’m sure there are better ways to earn a profit.

This is probably related to trying to match the i3 on price. Pretty sneaky way to get there, but it will work for the marketing people…

Both the B-Class and the i3 have their seat heaters as extra-cost options. The LEAF and the i-MiEV have that standard. They are trying EVERYTHING they can to lower the apparent price of the vehicles.

Power memory seats are standard, on the MB.

The $600 include rear camera and parking sensors

Well, waddia know? Thermal insulation and a direct heating defroster gains that much range? I hope they also have the regen levels set with paddles, and that it includes free-wheel coasting. This is on the Smart ForTwo ED, so I would imagine that it is on the B-Class, as well.

And the option to charge to 100% instead of a more conservative level is reasonable. Though I’ll bet they just make it standard, because most people will spend the extra money; having spent a lot of money on the car already.

I thought according to the American Chemical Society the sweet spot for charging was around 60% to get superior longevity in battery life. It appears the MB B and the Chevy Volt engineers are choosing this path with a minor twist from MB. They are giving a button to try and discourage regular use of the higher charge.

How does the specifics of the battery warranty read?

Well, first, Mercedes isn’t the first to advertise useable capacity. Toyota does with the Rav4 EV, and also advertises the standard and “extended” charge levels of 35kWh and 41.8kWh without charging $600.

This battery size was my guess the last time this was debated… it seems that I got lucky again:

Mercedes B-Class ED battery

36.0kWh total – 100% SOC
33.2kWh usable- 95.0% SOC
28.0kWh usable- 80.0% SOC
1.0 kWh unusable- 2.7% SOC

I also predict 3.7 miles per kWh at 65mph on level roads without heater use (LEAF gets 4.0, Rav4 EV is 3.4).

Mercedes B Class ED:

33.2kWh usable- 122 miles (almost 200km)
28.0kWh usable- 103 miles (a bit over 160km)

For comparison:

Range at 65mph (100km ground speed) on dry, hard surface level road with no wind or cabin climate control with new condition battery at 70F:

LEAF – 4 miles per kWh (250 wattHours per mile) * 21.3kWh = 85.2 miles

B-Class ED – 3.7 miles per kWh (270 wattHours per mile) * 33.2kWh = 123 miles

Rav4 EV – 3.4 miles per kWh (295 wattHours per mile) * 41.8kWh = 142 miles

@Tony: as ever, great analysis. Thanks.

Tony, I have driven my B-class for almost 1,000 miles and I can confirmt hat your analysis is correct. Careful (not fanatic) driving gets me 3.8 mi/kWh and over 100 miles of range before using the range extender

This is great news. A real shame it’s not super-charger or other QC capable. That would give a B-Class ED driver to go any where within major metro areas (San Diego/Los Angeles, Greater Bay Area).

Seems like an odd omission, given the small OEM cost and large utility.

Well, they are saying next year but if it is SAE rather than Chademo, they might as well not bother…

What if it was next year with Supercharger?

I am saying that a bit rhetorically, because obviously the decision to go with Frankenplug has likely already been made. Automakers are not good at short term changes.

If BMW and Nissan both jump ship to Supercharger, though, the Frankenplug world will crumble fast (not that there is much to crumble to begin with).

At about 1.7C, the B class can only take about 55 kW, or roughly as fast as the fastest combo CHAdeMO/CCS EVSEs. Pretty much a waste to try to DCFC this model.

Instead, they should offer dual charger option for 80A J1772 AC charging and the option to have a Tesla connector so that it is compatible with the Tesla 80A HPWC.

I follow your logic, but where are you going to find dual 10kw HPWCs? Even giving the MB B-Klasse a 10kw single on board charger is a waste, if you go on plugshare and try and find one. One could “picnic” at a 14-50 NEMA / campgrounds, but I’d rather wait on a 6.6kw Chargepoint unit (18miles/hr), near a mall, downtown, or a grocery store.

For sub-150 mile summer trips, I could see some content with a single 1-2hr stop, but this ultimately begs for more 50-135kw infrastructure. Units this MB can’t use.

The hpwc goes to 20kw (80A 250V).

..but where is someone going to take their MB ED, to find 20kw when they need it, which will be on the road not in their garage? Public infrastructure plans for 20kw A/C do not exist.

Guys, the car ALWAYS controls the charge, so this car will just fine with any available DC charge standard.

There are THOUSANDS of those around the world (CHAdeMO is near 4000 worldwide) and there are close to ZERO of the 80 amp J1772 / Tesla HPWC / Roadster HPC (70 amp).

They aren’t going to add an expensive onboard charger, but they might pop on a CHAdeMO port, at least for Japan. The CCS is dead-on-arrival in my opinion, particularly if BMW might jump ship to Supercharger. Of course, it’s dumb to offer the car without any quick charge standard, so offering CCS is only slightly less dumb.

I hope they bother since with this car plus CCS I could do almost all of my private longer trips.

I say still bother if it’s SAE (esp. for the CA market). The infrastructure will be developing in parallel, but not having a DC charging connector will impact the car for the rest of its useful life.

People keep forgetting that the CHAdeMO infrastructure was not built overnight. 2 years ago it was just as bad as CCS is right now. And I expect the car to last way longer than 2 years.

I would certainly get whatever DC charge port they offer, and hope for an adaptor to the standard that is still around in 5-10 years.

Terrific news, but where is this new info coming from? I just turned around for a minute to pick up my glass of wine and there is now an official EPA number of 87 mile range? Is the 36 kwh an extrapolation from the 87+20%=104 miles which can only come from 36kwh or has MB actually fessed-up on the battery size?

The 36 kWh battery is confirmed by Mercedes.

As for the ‘new’ 87 mile EPA rating (versus the 85 EPA estimated we have seen in print), Terry Wei (the Mercedes rep who works product and tech PR) is using that number…so until we see the official rating from the EPA in about a week’s time, we are going with that.

…but this is Mercedes, and apparently numbers can change on a whim, (;

Could it be that Tesla’s batteries aren’t too big on power density so it needs to build much larger packs than a hydrogen hoaxing client interested in an 80 miles compliance car is really interested in?

Maybe MB lost its nerve in the end and decided to make the extra capacity available to make it stand out from its main competitor (i3) more.

I bet more people will get the Mercedes than the RAV4 in a similar time frame.

$40k for a BMW or Mercedes or $50k for a Toyota.. The Toyota is history once again anyways.

Maybe the third time they decide to make an electric RAV4 it will stick around?

Or maybe for fun a hydrogen RAV4 for the ~12 stations in Cali and ~$9/kg hydrogen and 20 minute refuel time. What type of mpg does the hydro mobil get? Also; how big is the battery pack in the hydro buggy(it does have one)?

Show me a crash test of the 10,000 psi tank too. It’s got to be loud sitting inside when the tank ruptures?

Except the Rav4 has more range and $16,500 off the lease price. Of course, the Mercedes will still sell more because they are a CA compliance vehicle.

Many more people will buy the B-Class over the RAV4-EV for one simple reason: The RAV4-EV is not available outside of California.

When you go from 38 million Californians to 319 million Americans, you’re bound to sell more vehicles.

Mercedes B class ED will outsell the RAv4 EV in California.

Outselling Rav4 EV won’t be hard. Since Mercedes doesn’t yet have its 9 CARB-ZEV credit hydrogen car ready yet, they’ll want to stock up on as many credits as they can with the measley 3 credits this car gets.

They need these sold in CARB-ZEV “coalition” states – California, Connecticut, Maryland, Massachusetts, New York, Oregon, Rhode Island and Vermont, plus the headquarters state of New Jersey (seems silly to do this state to me). The chances of them seriously sold in other states is VERY unlikely, regardless of what they say now. VERY, VERY UNLIKLEY. See below as to why:

Model year — % of ZEV credits required

2012 ———— 0.79%
2015————- 0.79% (first year Daimler to comply)
2018 ———— 2.00% (first year “traveling provision” goes away)
2019 ———— 4.00%
2020 ———— 6.00%
2021 ———— 8.00%
2022 ———– 10.00%
2023 ———– 12.00%
2024 ———– 14.00%
2025 ———– 16.00%

One thing to note is that FCV traveling provisions continue after 2017.

I’ve a hard time figuring out why CA is so pro-foreign OEMs and so against home grown Tesla.

In what way is CA against Tesla? The state needs to push most automakers – Tesla is moving forward of their own free will. Taking away the battery swap extra credit makes sense to me.

It will be interesting to see which automakers are in a jam when the steep ZEV ramp (+2%/yr) starts in 2018. I suspect that Tesla will start realizing more revenue from ZEV credits by 2020 as other automakers can’t match the ramp and they start running out of their own banked credits.

Not coming to Canada….BOOOO!

This is a true 100-mile range EV. As Tony says, it should easily do 3.7mi/kW, so this is great news for anyone who feels range anxiety in a Leaf or anyone thinking the BMW i3 w/ extender is only option. The interior of the Benz is much, much nicer than the RAV, and I’m guessing its road manners are gentler as well.

I am also sad that it lacks QC, but it’s not a deal breaker if you need a longer-range urban commuter.

The battery of my Mercedes Benz B-Class E is dead,Can somebody help me find one in America?