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Old 05-23-2014, 06:07 PM   #15 (permalink)
redpoint5
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Quote:
Originally Posted by ConnClark View Post
Its probably in the unicorn corral because there is no real fuel saving to be achieved by doing so.
But it hasn't been shown that there is no fuel savings.

Various sources suggest that lead acid batteries have about a 50% charge efficiency. There is an inverse relationship between charge efficiency and state of charge. At about 50% state of charge, the charge efficiency is over 90%. However, lead acid batteries are normally operated at nearly full charge, which has a charge acceptance efficiency of 50%.

Capacitors have almost a linear charge efficiency of 95+ percent. This should translate into fuel savings, albeit very small.

I'll also note that LiPoFe4 batteries are more efficient than lead at accepting a charge, especially near the full state of charge. I believe they are somewhere around 80% efficient.

No unicorns here, just science.
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