Hybrid Vehicle - B-Class: revealing figures
This month Mercedes Benz will reveal their new hybrid vehicle, a converted B-Class which is now powered by a Hydrogen Fuel Cell. Following this, the vehicle will be leased from December this year in California for a test. California already has the so called ‘Hydrogen Highway’, a highway with conventional gas stations which also offer hydrogen on their menu. Although the initial plans for this highway was to have more stations with hydrogen available, the network would be sufficient for driving in California.
Revealing the new B-Class Back to the new B-Class, it has a 136 horsepower electric motor which is powered by 3.7 kilograms of hydrogen. The hydrogen is stored at a pressure of 700 bar and is supplemented by a 35 kW battery (though I assume they mean a 35 kWh battery). The battery is nicely tucked away under the floor, like it is with the A-Class. The total estimated range one can drive is 368 kilometres, which would equal a consumption of 86.4 kilometres per kilogram, according to the article.
I’m not so sure on the figures presented though and I think there has been a typo of sorts in it. Also note that the original article I first found on BenzInsider has disappeared again. However, having done a bit of maths, I’ll share this with you anyway.
As a given reference, the Nissan Leaf has a battery which is 24kWh, providing 160km of electric range. Given that the B-Class would have a 35kWh battery, the full range on the battery would be even more than 160km, but for the sake of comparison, let’s use 160km first and see how things go.
Option A First off, the full range of 368km and not using the battery. This would mean 3.7kg of hydrogen to be used for the total distance, would mean 99km/kg. That is more than what is stated, so there must be some battery power involved.
Option B The total range is said to be 368km. Subtracting the battery range of 160km, that leaves around 200km to be powered by the hydrogen fuel cell. 200km over 3.7kg equals around 54km/kg. Not the mentioned 86.4km/kg still.
Option C Using the provided mileage as a starting point, 86.4km/kg, with 3.7kg would drive you for a distance of 319km. That leaves rougly a difference of 40-50km that is covered by a battery, that sounds more like other hybrids on the market. Comparing with the Prius for example, which has a battery in the order of 3.5 to 5kWh and results in almost 40km.
Conclusion Since the vehicle is a hybrid (a drive train consisting of a battery and a fuel cell), I would expect it to have a battery which is more in the range of 5-6kWh than the stated 35kWh. Moreoever, with a 35kWh the fuel cell would hardly be used at all, assuming the B-Class is also a plug-in. Not really helping to evaluate how a fuel cell would perform for normal drivers.
The lease price of the vehicle will be announced at the moment the B-Class is revealed and includes hydrogen fill ups. So regardless of what the actual figures of hydrogen consumption are for now, the people driving it would be (a bit) less concerned. I’m hoping that upon revealing the B-Class they would announce the actual price, but I’m more interested in the actual specs now to see what they went for.