Charging your LEAF in a SHTF scenario

[DaveinOlyWA]

That is "up to" my neighbors best perfoance is like uhh "something" I forget but it not 100% and that high rate was only available like 4 hours a day so if L1 took 20 hours then a solar option might take 2-3 days

 

[keydiver]

How long would it take to charge the LEAF with that option?

Since the panels can crank out 1800w, It should be the same as any L1 charge.

The problem is that only the inverter can crank out 1800 watts. The solar panel is only 90 watts! How many amp hours is the internal battery?
IMO, the best way to do it would be to put together your own setup.
1) as many panels as you can fit or handle in an emergency situation. http://www.sunelec.com" onclick="window.open(this.href);return false; is my choice for panels
2) a solar charge controller that is compatible with your panels and battery sizing, and has a low voltage load cutoff to protect the batteries. I have a Morningstar ProStar 30M that I use for an emergency setup.
3) at least one, but preferable several deep cycle batteries to hold the charge until you need it. I have converted to good sealed AGM type batteries so I don't need to worry about watering. The more batteries you have, or the bigger they are, the better, because you won't cycle them as deeply while charging so they will last longer. If I recall, its best not to discharge them lower than 50%.
4) a minimum of 2000 watt 120 volt inverter to provide the AC for your factory EVSE.
Of course, you can "go large" on any of the above, and have enough power for a Level 2 setup to charge in half the time if necessary.
But, what you first need to do is calculate how many kWh you need per day, so you can calculate how much battery storage you need, and then from that calculate how many panels you need, which is also based on how many solar hours per day your area receives.
For me, in a SHTF scenario, I'd probably like enough power to drive at least 20 miles per day. At 4.5 miles/kWh, that's 4.4 kWh. At 85% charging efficiency, I would need 5.2 kWh into the EVSE. Then, based on 85% efficiency of my inverter, I would need 6.15 kWh of battery storage, which is a fairly large and expensive setup, especially if you only want to cycle them down to 50%. In South Florida, that works out to ~1.4 kW of solar panels to produce that much power per day, not a small setup for emergency use. We're talking about 5 or 6 230-270 watt panels.
The other option, which is much more practical IMO, is to have the large gridtied system, with a smaller battery backup inverter to spoof it, and just charge during the daytime when the gridtie system can produce enough for charging. That's my plan.

 

[kubel]

no power at all and you want to charge the LEAF? i would save all the solar to preserve your food supply. the LEAF should regen at nearly all voltage values by simply turning the wheel backwards while in drive.

Backwards while in drive? Wouldn't you need to go forwards?

I was thinking the biggest obstacle would be finding an energy source (whether wind, or flowing water) that could overcome the speed at which the car idles. With no resistance (jacked up), I wonder if it would be like a gas car and idle at a very high speed.

 

[TomT]

Electric cars don't idle. They have an artificial amount of torque applied to simulate the creep of a conventional automatic. It is something I hate and ironic in that ICE manufacturers have worked on all kinds of schemes over the years to eliminate creep...

I was thinking the biggest obstacle would be finding an energy source (whether wind, or flowing water) that could overcome the speed at which the car idles. With no resistance (jacked up), I wonder if it would be like a gas car and idle at a very high speed.

 

[videographer]

Dumb question: If the S really HTF, where would you want to be driving to 20 miles roundtrip a day? It would seem that any trips you make would be one-way affairs (e.g., to get as far away from the S as possible.) Personally, I think the Leaf would make a dandy UPS to keep the refrigerator running, and I hear that Nissan has released a module in Japan for just that situation.

 

[davewill]

Dumb question: If the S really HTF, where would you want to be driving to 20 miles roundtrip a day? It would seem that any trips you make would be one-way affairs (e.g., to get as far away from the S as possible.) Personally, I think the Leaf would make a dandy UPS to keep the refrigerator running, and I hear that Nissan has released a module in Japan for just that situation.

Ding! This would be the scenario where being able to use the LEAF as battery storage for my PV array and letting me run the house off the grid would make great sense. If I thought I could make that lash up for a reasonable price, I'd invest "just in case". However, driving the car anywhere would put a damper on that scenario. I'd either be driving during the day, and not charging the car up for that night, or I'd be driving around at night and leaving the house with no power. However, I'd have a charged car to use if that emergency hit where I just HAD to drive somewhere.

 

[DaveinOlyWA]

actually i am surprised given the ingenuity of this board that someone has not tried to jack up the LEAF to rig a pulley to the wheels. how much force would be needed? the creep on the LEAF does not provide that much torque. it wont roll up my driveway (in fact, i roll back which is not bad since all cars do...or at least all i have tried)

i am guessing some gearing along with a flywheel would be needed and i have to agree with someone who stated that in this scenario, you would only venture out for food i am guessing, so to the local grocery store to forage for the canned goods since by now, the rats would have gotten everything else. all this assumes the environment is still friendly enough for these trips. if not, why bother? its only a matter of time and probably not very much of that either but like any "Swiss Family Robinson" type movie, we have to have a fighting chance right?

so for that, the LEAF would provide several advantages; a renewable AND clean power supply, no fumes to deal with. a way to exercise (after all, you might become stir crazy eventually just sitting there) by setting up a stationary bike setup. it is conceivable the average garage would already have most of what you needed already.

 

[Metalman]

Do you think jacking up and then connecting the drive wheels directly to a windmill/watermill like device would provide enough power to turn the wheels fast enough to regen?

Possible? Yes. Do I think anyone will be able to do in any sort of practical way, no. I'm guessing the speed and force you would need on the wheels to get any kind of a charge is far more than what anyone is considering.

You want to charge the Leaf with an exercise bike?? It would be far more efficent to tow the Leaf with the bike than try to charge the battery with a bike and then drive the car. Why not just ride a bike where you need to go? It would be much more dependable in a situation like this.

 

[smkettner]

If you were determined to charge via the EVSE port, using GM's voltec L1 EVSE unit might actually be of some help since it has a lower amp settIing of 8 amps, which might be somewhat easier to produce on a SHTF scenario than the 12 amps required by the Panasonic L1 unit.

Also Leviton 120 L1 is switchable 7 or 12 amps 120 volts. My Prosine 1800 inverter seems to overheat with the Nissan L1. But the Leviton is too much $$ for just in case.

 

[DaveinOlyWA]

Do you think jacking up and then connecting the drive wheels directly to a windmill/watermill like device would provide enough power to turn the wheels fast enough to regen?

Possible? Yes. Do I think anyone will be able to do in any sort of practical way, no. I'm guessing the speed and force you would need on the wheels to get any kind of a charge is far more than what anyone is considering.

You want to charge the Leaf with an exercise bike?? It would be far more efficent to tow the Leaf with the bike than try to charge the battery with a bike and then drive the car. Why not just ride a bike where you need to go? It would be much more dependable in a situation like this.

whoa!! what?? wait a second... i need to clarify something here.

if you jack the LEAF up, put it in drive and it spins at say 4 mph with no load all i have to do to generate power is to make it spin at 5+ mph correct?

because jacking it up, putting it in drive then spinning the wheels backwards would be EXTREMELY difficult to do without some big time rigging and a lot of starting torque...

or am i way off?

 

[Nekota]

Take a 55 gallon drum and insert a couple of tires with axle bearings (wheels) to provide a means to support and rotate the LEAF front wheels. Power the drum with a motor using v-belt driven pully. The motor could be a 2 to 20 HP IC engine (e.g. lawn mower) or a DC electric motor. In the case of the DC electric motor you could use the DC from solar panels to power the DC motor. Place the emergency brake on and put the LEAF in reverse then apply power to the drum rotation system. Adjust motor speed for regeneration level. If you can island the inverter from the disconnected grid, a universal AC/DC motor could provide the power from the AC from the PV inverter.

 

[smkettner]

Or walk or bike.

 

[planet4ever]

I was thinking the biggest obstacle would be finding an energy source (whether wind, or flowing water) that could overcome the speed at which the car idles.

Electric cars don't idle. They have an artificial amount of torque applied to simulate the creep of a conventional automatic.

Quite true, Tom, and quite beside the point. What you have to do is reach the speed and power where the car supports any significant amount of regen, and in my experience that is many times faster and more powerful than any creep speed and energy.

But Metalman and smkettner have it right. The only practical forms of transportation in kubel's scenario are walking and biking, unless you happen to have a horse (or camel, llama, burro, ox, etc.) in your back yard.

davewill is also right, though, that the LEAF would make a very good storage battery for a solar electric array. My 7kW array of panels often generates 25-30kWh on a sunny spring or summer day. Personally I would never allow or support direct DC/DC charging from solar panels to battery, but solar -> house inverter -> EVSE -> LEAF charger -> battery would work just fine. All you need is a 60-cycle signal generator to fool the inverter into thinking it is connected to the grid. Going in the other direction it seems like it shouldn't be too difficult to tap DC voltage coming out of the battery before it goes through the car's inverter, and feed that to the house inverter.

Ray

 

[TonyWilliams]

Going in the other direction it seems like it shouldn't be too difficult to tap DC voltage coming out of the battery before it goes through the car's inverter, and feed that to the house inverter.

Ray

So, we micro-inverter guys are out of luck?

 

[planet4ever]

Going in the other direction it seems like it shouldn't be too difficult to tap DC voltage coming out of the battery before it goes through the car's inverter, and feed that to the house inverter.

So, we micro-inverter guys are out of luck?

Well, I guess you could try to find some 15-pole double-throw switches so you could dynamically rewire groups of them in series every night. :lol:

(400v/15 = ~27v, which I think your micro-inverters would like.)

Ray

 

[davewill]

... the LEAF would make a very good storage battery for a solar electric array. My 7kW array of panels often generates 25-30kWh on a sunny spring or summer day. Personally I would never allow or support direct DC/DC charging from solar panels to battery, but solar -> house inverter -> EVSE -> LEAF charger -> battery would work just fine. All you need is a 60-cycle signal generator to fool the inverter into thinking it is connected to the grid. ...

It would be useful to build an OpenEVSE and program it for this purpose. you would want to dial the EVSE's pilot up and down as your solar array's output and/or the house's draw changed during the day. You'd have to be careful to avoid drawing more than the solar is producing as that would cause a brownout, and obviously you want to store as much of the excess output during the day as possible.

So, we micro-inverter guys are out of luck?

You'd just need a separate inverter to run the house from the car's battery...which is probably a better solution, anyway. I see problems with sharing the inverter...you'd end up have to manually shut everything down during the two daily switchovers and would have to be careful not to allow the solar system to brownout badly.

 

[Metalman]

Now this would work.
http://www.youtube.com/watch?v=_xUSPaJFy3g
I've been in there when it's operating and it's pretty neat. I would think there is plenty of power there to charge a Leaf. Drive on set of rollers and you're all set.

 

[Nekota]

Do you think jacking up and then connecting the drive wheels directly to a windmill/watermill like device would provide enough power to turn the wheels fast enough to regen?

Possible? Yes. Do I think anyone will be able to do in any sort of practical way, no. I'm guessing the speed and force you would need on the wheels to get any kind of a charge is far more than what anyone is considering.

You want to charge the Leaf with an exercise bike?? It would be far more efficent to tow the Leaf with the bike than try to charge the battery with a bike and then drive the car. Why not just ride a bike where you need to go? It would be much more dependable in a situation like this.

Windmills for LEAF power?

World's First Wind-Powered EV Charging Station Debuts in Spain

Not a direct connection to the wheels but when I saw the article I remembered this comment in the thread.

http://www.ibtimes.co.uk/articles/20120816/world-039first-wind-powered-charging-station-debuts-spain.htm" onclick="window.open(this.href);return false;

 

[derkraut]

Now this would work.
http://www.youtube.com/watch?v=_xUSPaJFy3g
I've been in there when it's operating and it's pretty neat. I would think there is plenty of power there to charge a Leaf. A drive on set of rollers and you're all set.

You guys crack me up!! :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

 

[Metalman]

Bringing this up from the dead.
I found these on YouTube. They may put the charging with a bike into perspective.http://www.youtube.com/watch?feature=player_embedded&v=7l_RbsLYCVA
http://www.youtube.com/watch?feature=player_embedded&v=C93cL_zDVIM