 Battery 2
kfz-tech.de/PME79
Quick sentences are poison for a sensible technical discussion. One such comment should be briefly highlighted here: The significantly higher weight of a purely electric car is therefore not significant compared to the
consumption of a combustion engine, because this would be recouped through recuperation. In addition, cooling air flows through the engine room of a combustion engine, which also causes losses.
The fact that the losses in aerodynamics are significant under completely different circumstances than those caused by high weight is not taken into account here at all. Surprisingly, the consumption of an electric car
increases more at higher speeds than a vehicle with a combustion engine.
No, they will never be completely alike. Just take the VW Golf as a basis. As an ID.3 it consumes around 20 kWh at 120 km/h under good conditions, and as a diesel it consumes around 5 liters/100km. Both are values from
the on-board computer. If the diesel consumes 5.5 liters, we add the charging losses of the ID.3. Overall, the calculation obviously works out in favor of the electric car, because 20 kWh corresponds to around 2 liters of
diesel in terms of calorific value.
The electric motor is supplied with energy that is much easier to convert into movement. The combustion engine's energy is packed much more densely. In this comparison, a 50 liter tank would correspond to a 500 kWh
battery weighing around 4 tons. If we calculate the weight of the tank generously at 50 kg, the electric car carries 80 times as much tank weight with the same range, although it saves some of it on the engine and a lot on the
clutch, transmission and, for example, the exhaust system.
The electric car also needs a certain amount of airflow because hardly still any of them are cooled solely with air. Liquid cooling seems to be extremely important, especially when charging, in order to guarantee a high initial
value and, in particular, a certain stability of the charging power. By the way, do you know why the consumption stated by the manufacturer multiplied by the range often results in a higher battery capacity than the existing
one? Because charging losses are often taken into account here. This leads to the paradoxical case that the WLTP value, which is already set far too low, should actually be even lower.
What else is constantly being cited as an advantage for electric cars? Oh yes, the recuperation. Quite incomprehensible, because people act as if this were a unique selling point and thus only be possible with electric cars.
Do you know that there are even sets for retrofitting something like this to a normal car by replacing the generator and adding an additional control system? Don't do it, because such systems are not very effective.
Now we want to separate one occurrence of recuperation, namely that which occurs when braking more or less sharply. You can easily understand this. You just need to stop the time when you do something like that. Just
as a guide: braking sharply from 100 km/h to zero takes about 3 seconds. So now you can think about how an incredible amount of energy can be recovered during this time. You know what, we just forget about that part.
Apparently it is still not implemented at Tesla.
Now we come to the part that rightly makes fans of electric cars so proud: the long downhill journey. Can the combustion engine hold its own here? Only with effort, so that one has to ask whether it is worth it, for example, for
living in a lowland. You would have to install a battery of at least the size of the expected energy recovery, or better, twice as much. Plus an electric motor on the crankshaft and/or perhaps even better on the turbocharger.
Admittedly, not exactly cost-effective, but comparably effective in case of recuperation.
So in the mountains, the electric car secures points because there is no additional effort required for recuperation. But what is it like in the relative flatlands? There are now not only automatic transmissions, but also electric
clutches with a costing function. The variant with the engine switched off is even more cost-intensive because various auxiliary units have to be electrified. But anyone who is confronted with such a system will first notice at
how many places in normal traffic 'sailing' is possible.
However, if you shy away from all of these additional expenses and still want to do something for consumption or rather the environment, recuperation is a thorn in your side anyway. Sure, it's convenient to drive completely
with just one pedal, but is it always fuel-efficient? Probably not, as driving experience shows, where almost every time you release the accelerator pedal you also take the gear out of gear. Admittedly, the engine continues to
run, but with a consumption that is sometimes well below one liter per hour.
No, once you've practiced it, you won't notice anything. After a while, you will no longer be aware of the fact that you should not stubbornly maintain this driving style without frequently looking in the rear-view mirror. What you
notice is how often people brake unnecessarily in normal traffic, even though it's already moving slowly enough. And if you then take a closer look at your consumption, especially in city traffic, you will get a feeling for the
importance of recuperation and how much of it can already be achieved with a normal combustion engine.
kfz-tech.de/YME42
| 
