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Re: Could a Leaf rescue another Leaf?

Tue Sep 06, 2011 10:58 am

Yeah, charging via regen towing is an old idea that works, but is a bit hard on the car.
There are some who have made gasoline powered "pusher" trailers so that you can temporarily add a "range extender" too.
Neither of the ideas are anywhere near mainstream right now.

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Re: Could a Leaf rescue another Leaf?

Tue Sep 06, 2011 8:12 pm

Stunt822 wrote:So the best way to rescue would be to - park as soon as you have VLB warning, and get towed by strap - getting juice from regen. Even with another Leaf.

I would second what Herm said earlier on this:
Herm wrote:You are not supposed to tow with a Leaf, but I'm sure you could if you are careful and keep it slow. Use a towing strap and not a chain. Dont mess around with tow regen to recharge the dead leaf.

Trying to use battery power from one LEAF to drive regen to charge a second LEAF has got to be terribly inefficient. You could get both cars a lot farther by towing slowly in neutral.

However, do be aware of the warranty, which Herm also alluded to:
This warranty does not cover damage, failures or corrosion resulting from or caused by:
  • Failure to operate the vehicle in accordance with the OWNER’S MANUAL.
  • Misuse, such as overloading, using the vehicle to tow, driving over curbs, or using the vehicle as a power source.

I believe in being nice to other LEAF owners, but you are not going to talk me into voiding my power train warranty by towing your LEAF. I'll be happy to call the free towing service for you if your cell phone isn't working.

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Re: Could a Leaf rescue another Leaf?

Tue Sep 06, 2011 8:39 pm

Join Plugshare and you'll never be more than a few miles from a charging dock. Well, that's the theory anyway.
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Re: Could a Leaf rescue another Leaf?

Thu Sep 08, 2011 9:10 am

planet4ever wrote:I believe in being nice to other LEAF owners, but you are not going to talk me into voiding my power train warranty by towing your LEAF.

Just don't cause damage, and there will be no problems:)

Again, for people who treat car as a black box with steering wheel - towing is prohibited! You have to know what you are doing. And even Nissan doens't say towing is not allowed - they say if you damage it - they aren't paying. Fare.

Why I would use some regen, if being rescued - get some buffer to get up the driveway, or probably up few blocks from main road, so I could let other person go. I agree on total inefficiency of such charge - i'd estimate 30% of efficient, vs when towing in neutral (lossed on conversion, charge and discharge)

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Re: Could a Leaf rescue another Leaf?

Thu Sep 08, 2011 9:46 am

i think the original idea behind the OP was wondering if there was a way to transfer some charge from a fully charged Leaf to a depleted Leaf. this towing conversation is ridiculous.
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Re: Could a Leaf rescue another Leaf?

Thu Sep 22, 2011 12:04 am

DaveinOlyWA wrote:there were people in the netherlands?? or Norway maybe that recharged a Leaf by towing. they actually added two bars.

In the Netherlands. You can see the video on Youtube: http://s.meulie.net/n15dtz 8-)

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Re: Could a Leaf rescue another Leaf?

Thu Dec 22, 2011 12:03 am

pasowino wrote:What about a chadmo to chadmo DC cable that can connect the two cars together? I'm sure there is some firmware setting that doesn't allow reverse current flow from the DC QC port, but with a little ingenuity and the right cable, I suppose it seems possible to share a few KWH with another leaf.

Something like that would be fast relatively simple. The problem is that a mostly fully charged battery has the same terminal voltage as a mostly depleted battery. There's no voltage to push significant current between batteries.

The answer for this is to include a voltage booster that also handles large currents. The voltage boost might not need to be very great.

Something like this already exists for 12V cars. A special cable plugs into the cigarette lighters of two cars (one needing a jump, the other fully charged). This "cable" includes a voltage booster to raise the 12V from the source battery to 13.8V to charge the dead battery.
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Re: Could a Leaf rescue another Leaf?

Mon Dec 26, 2011 8:04 pm

The LEAF's Battery Pack is about 395 volts when full, and under about 300 when near empty.

It only takes about a 10v surplus to drive 50 amps into the pack, and a drop of maybe 10v to supply the 50 amps from another pack.

So, approximating that a 20v difference might make 50 amps flow, a 100v difference might make 250 (or 1000) amps flow, way too much to be healthy for either battery.

Now, adding a 2 ohm (5000 watt) resistor in series between the battery packs might limit the current to something like 40 amps ... which might actually make the "rescue" workable.
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