Simple answer (already raised)... Conservation of Energy. No energy cycle is perfectly elastic, all energy conversion incur some loss.
Lets just guess on the efficiencies, you can fill in your own numbers later if you like.
- Regen - 95% - Mechanical efficiency of the electric motor generator converting kinetic energy (motion) to electricity.
- Battery Charge - 95% - Chemical efficiency of turning electricity into chemical potential energy (this is how batteries store charge).
- Battery Discharge - 95% - Chemical efficiency of turning chemical potential energy into electricity.
- Assit - 95% - Mechanical efficiency of the electric motor generator in converting electricity into kinetic energy.
That translates to a 77% (95% * 95% * 95% * 95%) round trip efficiency. So you only get 77% of the energy you try to store, back when you need it. It suggests that you shouldn't try to use it, if replacing it has such a toll.
Don't confuse this with Thermal Efficiency. That's a different subject. This assumes you already have the energy. Do you use it or store it. I say use it.
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