Quote:
Originally Posted by Logic
In an EV it seems a shame not to buffer the batteries with supercaps.
Capture more regen energy and save the battery from high discharge rates when accelerating.
Perhaps the power added doesn't offset the extra weight and space.
Apparently this is called Hybrid Energy Storage System (HESS) and is a thing still.
All this could use its own topic.
|
The main issue with supercaps in conjunction with EVs and hybrids is that you can't really put them in series.
If you put two battery cells in parallel, you double their amp hours. If you put two in series, you double their voltage. Both result in doubling the watt output, and double the stored energy.
If you put two capacitors in parallel, you double their capacitance (equivalent to amp hours in battery cells), but if you put them in series, you double their voltage, but also
halve their capacitance, so you don't double your energy storage. For a 300 volt hybrid, you would need 100-120 supercapacitors in series, which would divide their capacitance by 100-120, effectively making them useless.
I am not sure why large capacitors have never scaled up in voltage, but there is probably a good physics reason for it.