[Tahoe_Hybrid]

Originally Posted by Isaac Zachary

Very probable.



The hydraulic hybrid was never intended to be a means to store massive amounts of energy but to work exclusively as a traditional hybrid that helps save fuel through regenerative braking. It only makes (made) sense on stop and go vehicles. Vehicles that cruise down a highway wouldn't benefit much from the regenerative braking.

At the time there weren't any Li-ion hybrids or EV's. The only thing that came close were the NiMH hybrids, namely the 1st Gen Honda Insight and the 1st and 2nd gen Toyota Prius. The NiMH hybrids were said to get up to 20% or 25% regen efficiency and weighed more per unit of power.

By comparison, the hydraulic hybrid systems that had been developed and tested at that time were 70% to 80% efficient at regenerative braking and were light enough to be easily adapted to commercial vehicles that normally need all the weight savings they can get in order to haul their cargo. For an example, on a full sized bus the hydraulic hybrid system might mean you would lose one passenger in capacity. (This is why many have serious doubts about a Tesla or other company produced battery electric semi truck. The added weight of the batteries displaces the weight of the cargo that can be carried.)

Anywho, for hybrids at least maybe the lithium ion battery caught up to and surpassed the hydraulic accumulator in power to weight ratio or effiency (I've seen claims of Tesla regen being 85% or even 95% efficent although I have serioius doubts.) Even if li-ion batteries don't surpass it in those aspects, they definitely do in terms of energy density, making li-ion batteries better for certain applications.

For an example, anything plug-in (hybrid or pure EV) would benefit from a li-ion battery. Also when traveling over mountains a lithium EV or hybrid system would help soak up energy while regening down the pass. These are things that cannot be done in a hydraulic hybrid.

I think what attracts me to the hydraulic hybrid idea is that it isn't affected as much by cold weather. My NiMH hybrids suffer quite a bit during the winter, and I'm sure a lot has to do with battery temperature since I can warm up the engine and catalytic converter, keeping the heater off, and still drive around without the engine ever wanting to shut off. And in our Nissan Leaf the cold still took a huge toll on range even when trying to hypermile without turning on the heater.

the issue with lithium is it bad for the environment, creates waste and can catch fire... Zero waste option