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Old 01-20-2011, 03:47 PM   #7 (permalink)
mnmarcus
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Quote:
500 KW seconds versus 300 W hours.
3600 seconds per hour.
500 kW seconds -vs- 1,080,000 W seconds (which would be 1,080 kW seconds) would mean the avg. Li-on pack would dis/charge 2x as fast as the best hydraulics? Someone has made a mistake there.

But dropping the /kg units changes what we are talking about completely. Or is it 500 kW*sec/kg ? That might make more sense to me. That would mean you'd need twice (by weight) the accumulator to equal a Li-on pack...

So 2 identical engineless vehicles except ones has a 200 kg Li-on with an extra 200 kg "equalizer" weight added and the other has a 400 kg hydraulic accumulator. Say also each's motors are magically the same. They are fully charged and take off at max acceleration in a straight line until their respective packs are empty. IF discharge rates are the same they would run the same distance neck and neck till there packs were empty, right? Then the BOTH switch to recharge mode and start filling at max. The hydraulic recharges to only 80% because of inefficiencies until stopped while the electric charges to only about 25% in the same amount of time (but has not stopped?) The main advantage being that you can charge the accumulator more fully in the same amount of time than the Li-on?
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