BMW’s CEO Harald Krüger is now confirming the information that was already announced in this website.
“The battery cell technology is evolving. An increase in range of the i3 will come in the 2016. A bigger technological leap is likely to happen in the next three or four years. You can then travel almost twice the distance without a further increase in battery weight.”
The new Samsung SDI’s battery factory in China is already producing the new 94 Ah cells that will be used in BMW i3. BMW i3 has a battery made by 96 cells. These cells have 60 Ah and 3,7 V of nominal capacity and voltage. This gives a total battery capacity of 21,3 kWh (96 x 60 Ah x 3,7 V). If we change the 60 Ah cells to 94 Ah we get 33,4 kWh. This is the total capacity, the usable capacity can vary from 90 % and 80 % of that.
But what does it mean in electric car range and battery capacity. Moving from 60 Ah to 94 Ah cells represents a 57 % increase in capacity. Does it mean an equal increase in range? Not necessarily, but almost. Having a newer cell with the same volume doesn’t mean the weight is the same, higher weight of the car decreases its range/efficiency. But higher battery capacity can improve its discharge efficiency because of the Ragone Curve. For the sake of simplicity we can assume the 57 % increase in battery capacity means an equal increase of the range. We can expect BMW i3 improve the EPA range from 81 miles (130 km) to 127 miles (204 km). Not bad at all.
What can we expect in 2 or 3 years? I can tell you that Samsung SDI already has 120 Ah cells wanting to be used…
The continuous energy density increase in battery cells will make the gas range extender obsolete sooner or later.