Irony

[smkettner]

Why would you not let him put his boost cables to the 12v battery?
Does the manual warn against this?

I think Gudy did the right thing - unless Leaf manually specifically talks about how to use the battery for jump start - I'd not do it either.

If the manual doesn't talk about it - that is a good question to ask Nissan ...

The guy needed a jump. I would tend to want to help him even if there is some risk.
I maybe would have whipped out the manual to check.... and I hope Gudy does and posts the info.

 

[TRONZ]

I thinks we really do need to read the manuel on this one.

 

[LEAFfan]

Does anyone know if the LEAF has a similar arrangement? Wouldn't it be cool to have a few lights on in your house when everyone else is sitting in the dark? If you try to do this, though, I'd recommend buying a pure sine wave inverter.
------------------------------
LEAF SL brilliant silver + Level 3
Reserved 4/20 3:20pm PDT
Ordered 10/1 1PM
Pending

If you do that, it will void your battery warranty. Nissan may have a way of detecting that connection also.

 

[driveleaf]

Sigh. I see my attempt at an analogy was lost. Sorry groundloop, I am not making this up as I go.

Either way, I would firmly stand on the not jumping an ICE out of protection for the leaf. I imagine Nissan lawyers will have written the manual to say the same.

I would be perfectly willing to help the guy outby calling AAA.

 

[walterbays]

The little "motorcycle" battery in a Prius isn't big enough to jump start an ordinary car. http://priuschat.com/forums/gen-ii-...76-jump-starting-another-car-using-prius.html Indeed I carry a 12V lantern battery in my Prius which I can use to jump start the car (start the computer to throw the main battery relay really) if needed. I'd expect Leaf to also have a small battery that could not crank a V6.

 

[garygid]

Probably 8 "D" cells would "boot" the Prius. Possibly even AA cells.

We will have to see what one needs to "boot" the LEAF.
If the BIG 12v battery remains connected to the 12v buss, one might need a noticably "stronger" 12v source to "boot" the LEAF.

 

[Coffee_Slurry]

The little "motorcycle" battery in a Prius isn't big enough to jump start an ordinary car.

That's the Prius. The Leaf has a full-sized car battery.

I still wouldn't jump start an ICE with it, for fear of damaging the Leaf's little DC/DC convertor, but the battery itself probably has 500+ Cold Cranking Amps, like any other car-sized wet lead acid battery.

That said, I have no idea why the Leaf has such a huge battery. Seems like total overkill to "boot" the car.

 

[UhClem]

Gary is right. the Prius cannot jump a regular car which could need a hundred amps.

Actually, it can. I jump started a co-worker's Ford Explorer with my 2007 Prius :lol:

 

[garygid]

It does more than "boot".
It powers ALL the Accessories when in "Aux Mode".

 

[Nubo]

The little "motorcycle" battery in a Prius isn't big enough to jump start an ordinary car.

That's the Prius. The Leaf has a full-sized car battery.

I still wouldn't jump start an ICE with it, for fear of damaging the Leaf's little DC/DC convertor, but the battery itself probably has 500+ Cold Cranking Amps, like any other car-sized wet lead acid battery.

That said, I have no idea why the Leaf has such a huge battery. Seems like total overkill to "boot" the car.

If you ever do run out of traction battery on the road, having a standard-size 12V accessory battery would be useful, to keep the lights on, emergency flashers,operate the e-brake, etc.. And maybe a little entertainment while you wait for a service vehicle.

 

[johnr]

Nissan intended this car for the mass market. And sooner or later some LEAF owner WILL try to help a stranded ICE driver with a jump-start. And the LEAF might or might not be turned on at the time. So if it would be harmful to do this, I'm sure there is a big warning in the manual about it - and if not, then chances are that Nissan has made the necessary precautions. That said, I'm really curious to know for sure!

 

[Coffee_Slurry]

If you ever do run out of traction battery on the road, having a standard-size 12V accessory battery would be useful, to keep the lights on, emergency flashers,operate the e-brake, etc.. And maybe a little entertainment while you wait for a service vehicle.

You're probably onto something there.. might have to have enough power to run the headlights and flashers and carwings for some amount of required time.

 

[LEAFer]

If you ever do run out of traction battery on the road, having a standard-size 12V accessory battery would be useful, to keep the lights on, emergency flashers,operate the e-brake, etc.. And maybe a little entertainment while you wait for a service vehicle.

You're probably onto something there.. might have to have enough power to run the headlights and flashers and carwings for some amount of required time.

Good point. So how does that work in a Prius ?

 

[garygid]

Basically, I think you have to leave the Prius turned ON, or maybe the Aux Mode turns the car "On", but just does not let the car "drive"?

 

[PaulScott]

I've used our RAV to jump ICE cars before with no negative results. I don't recall having the car on, though. I've heard of RAVs being "jumped", too. The aux batteries are needed to get it started, and sometimes a RAV would get a bad aux battery. That worked, too.

 

[LEAFfan]

That said, I have no idea why the Leaf has such a huge battery. Seems like total overkill to "boot" the car.

The reason it has a regular car battery is to run most of the accessories including the LED headlights. It isn't just to boot the car starter.

 

[Herm]

A couple of things.. you guys are assuming that because the LEAFs battery looks like a normal battery that it is, perhaps its not designed to deliver the hundreds of cold cranking amps that normal cars need.. the battery may have been optimized for high capacity and low self discharge (similar to the battery used in a UPS or an alarm). Such a battery may be able to jump start a car (one that starts easily, and does not need to be cranked for 30 secs, and not in winter) but will probably suffer a reduction in its life.

Some Priuses have suffered several thousand $$ damage from improper jumping.. probably a spark at the wrong time fried some electronic box in the Prius. I have seen some people "test" the polarity of a jump connection by briefly dragging the clamp over the battery terminal, if they see a shower of sparks then they switch the polarity.. I just cringe since many batteries explode when this happens, spewing acid all over.. that momentary shower of sparks is enough to damage or destroy some expensive components.

So I would recommend you NEVER jump start another car with a LEAF. I would do it, but not a real jump start.. I would carefully connect both batteries in parallel, turn the LEAF on and let it recharge the dead car's battery (with everything off, and make sure the driver is out of the car so he does not try to "help" you out by attempting a start), let it charge for about 5 minutes, disconnect the cables and try to start the car.. it usually works, assuming the battery is not so far gone and corroded that it cant take a brief charge.

Be very careful when making that connection, avert your face since many lead-acid batteries do explode. Its better if you use modern jump cables, with polarity reversal protection and a way to make a remote connection.

 

[Desertstraw]

I have jump started a Prius with a Prius. There is even special contact points under the hood for doing it. No idea if the Leaf has such contact points but since the Leaf uses a standard 12 volt system I would not be surprised it can do the same. Hopefully the solar option will prevent a Leaf from needing a jump start itself!

By the way the reason the Prius needed a jump was that the hatch was not shut all the way so the interior lights remained on until the 12 volt battery was so low the car would not start. Of course "start" in this case is really "turn on" in the Prius just like I suspect it is in the Leaf.

How did you do it? The only way that I know is on the battery in back..

 

[garygid]

On the 2010 Prius there are special, almost-hidden contacts in the fuse box up under the hood, located more toward the driver's side.

They are not trivial to find or connect to, particularly on a rainy night in the dark.

I suggest becoming familiar with each emergency system on any car you drive, especially if doing night driving. It is hard enough to find things, open things, read the fine print instructions, etc. in the dark.

Same advice for fire extinguishers and flares added the auto or home, and the turn-off procedures for the car, and water, electricity, and gas at home.

 

[ERG4ALL]

My experience with lead-acid batteries is that they can be "dead" for two reasons. First, I would try to determine why the other car's battery is dead. Is the battery okay and someone just left the lights on overnight and the car won't start, or did the person drive up to where they are, got out and ran an errand, and then got back in and the battery was dead. The former case may make it easier to start the ICE. The latter is more problematic. In the latter case it usually means that enough of the battery plates have disintegrated and fallen to the bottom of the battery and caused the plates to short out. In this case, with a direct short in the battery it will take a larger amount of current to get that car started which may overwhelm the LEAF battery.

I asked at the test drive if the lead-acid battery is charged at the same time as the propulsion battery and the answer was yes. Thus, there is some circuitry that takes some current from the EVSE and charges the 12V battery. I'd do like gudy and politely opt out of starting the ICE. Usually, when a lead-acid battery has gone bad there are some signs (age, slow start, different sound when the engine turns over, low electrolyte) that the owner should have paid attention to and didn't.

You also run into another problem when starting a dead battery ICE. That is whether it is an automatic or a stick shift. The majority of ICE cars are automatics. Thus, even if you can get the car started with a jump, you have to keep the RPMs up enough to have the alternator provide enough current to keep the car running. So even if you get it started you have to be throwing the car in gear at other than idle and throwing it into neutral at stop lights and repeating the process until you get to the shop. This can be hard on an automatic transmission. If the tranny has had the same amount of maintenance as the battery the owner may do some damage that will cost more than the tow. Like someone else stated, I'd help by calling a tow truck for them.