Roll system for Quick charging with Regen Brakes

[harryjpowell]

Not sure what planet people live on, but I think that most everyone would pay to eRefuel something close to what their alternative would be. 70-80 mile charge is roughly 2-4 gals of gas, so at 3.50 your talking about $7 to $14.00 for a QC.

Remember this is only to get between your normal L2/L1 home/family or recreation etc. with a few stations around I can justify getting rid of my second car for the occasional $10 QC to move my leaf on longer trips. The cost of a second car is well covered. you could probably even factor that "benefit" into a bit extra on top of a QC.. Your surely going to cover whatever operating expense, Natural Gas/Solar/Grid, at those rates so its just a question of the asset investment and maximizing some additional margins...

If you expect free stuff like QC's you must be part of the Occupy WS movement, who probably won't afford a leaf anyway. "pointless idea in general and not worth discussing" as a previous poster said are just the attitude to hamper development and thinking outside the box. No offense but feel free not to comment..

 

[Nubo]

I find the roll charging system to be worth considering since the "electric powertrain" in the LEAF is reported by Nissan as up to 95% efficient (SAE Vehicle Electrification Feb 2011) at about 6000 RPM and 125Nm torque.

Even if that were true, a roll-charger doesn't add anything beneficial to the equation. Whatever electricity is captured through regen is still less than the energy input to the roller motors. On top of the losses attributable to regen, there will be losses converting electricity to motion by the roller motors, bearings, tire rolling resistance, etc... Why sustain all those losses and mechanical wear when you can just plug the vehicle directly into the power grid?

The one advantage is access to a 30KW charge power already built into your vehicle for a 45 minute equivalent DC quick charge. As for wear on the tires, remember this is rubber on steel which is very similar to fan belts on pulleys, so the tire wear would be much lower than typically expected for roads. Another factor is one can resort to other sources of mechanical energy - not just electricity. For example flywheels or compressed air to store energy and there are times when the power grid will not be available. I don't think it's the best system for charging but it has possibilities and provides another way to charge the battery.

If there's already that level of power available to run the roller, converting it to DC for L3 charging will be a better option.

I have an indoor trainer for my bicycle and I have learned to use it with old tires because it does wear them; particularly the tire deflection is greater than rolling along pavement. The sidewalls are stressed. But there's more wear -- you are wearing the vehicle's drive train, transfer case, wheel and motor bearings. The roller device also has wear items, bearings, motors...

Flywheels may well have a role, in that they can accumulate energy over time and then dispense it quickly. But this is best done by using regen at the flywheel - producing electricity. And so we get back to simply plugging the car into the electricity source.

 

[Nekota]

And so we get back to simply plugging the car into the electricity source.

Those bike "fans" use a very small diameter shaft which is usually knurled as well and I'm not surprised it's extra rough on bike tires.

I'm afraid we are going to be waiting for the simple :roll: 60KW DC power source for a very long time

 

[DaveinOlyWA]

i had to think that this thread was started on a "in case of emergency" situation.

iow; this is not a discussion on a viable long term solution. a more of a "what if?" thing.

also. one thing that i am not sure of is the car's ability to regen at that high a rate for that long of a time period.

sure it can QC that fast but QC can go much higher than regen can so wondering if the circuitry would be the same or have the same capability. i would have concerns that extended run times at high regen could be detrimental.

granted we have several people here who have done it (including me) for 5-10 minutes on long hills but at the same time, getting back 2 bars in 10 minutes is not the same as getting near a full charge in 45 minutes.

QC is DC to DC. regen is AC to DC.

dont have the knowledge of how the car handles this so any thoughts on that?