# 2014 Leaf Modules no voltage ??



## Boulder Hybrids (Jan 30, 2013)

A couple months ago I bought a low mileage wrecked 2014 Leaf and harvested the modules out of the battery pack. All were good, and the ones that "have been sitting" for weeks _still_ read over 4V per side.

A couple weeks ago I purchased another complete 2014 pack. The seller says the modules were tested before shipment, and they had appropriate voltage. 

They arrived in Colorado, we removed the bus bars then removed the modules from the Nissan battery box and every single module tested at zero volts. (yes I checked my Fluke and tested on copper terminals not the screw holes)

Does anyone have any idea what happened? I can't see how the cells would die in a 3 day shipment, unless it has something to do with pressure (I'm at 5000 feet, the battery came from near sea level and the Nissan battery enclosure had been cut open before shipment).

Can these cells be revived?


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## 67BGTEV (Nov 1, 2013)

I don't think it can go dead in 3 days. The may not be revived, based on theory.


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## twright (Aug 20, 2013)

Its surprising to me that you read "0" volts. It is unlikely that all of the batteries put out nothing , unless there is some kind of open fuse.

Is there some sort of fusing that has blown?


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## onegreenev (May 18, 2012)

Boulder Hybrids said:


> A couple months ago I bought a low mileage wrecked 2014 Leaf and harvested the modules out of the battery pack. All were good, and the ones that "have been sitting" for weeks _still_ read over 4V per side.
> 
> A couple weeks ago I purchased another complete 2014 pack. The seller says the modules were tested before shipment, and they had appropriate voltage.
> 
> ...


If they are truly at zero volts I'd insist on a refund. Hard to believe that they are all at zero and if they are it is most likely that they we're at that point prior to shipping.


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## dougingraham (Jul 26, 2011)

Something is wrong. Even if you shorted the individual cells with a resistor for a couple of days so that it read zero it will come back up once the resistor is removed. If the pack was discharged when it was pulled from the car and someone discharged it more with a resistor you would never see zero volts on all the cells. Some would still have positive voltage and some would be reverse charged. But even the ones that are reverse charged are going to have a potential.

Verify the meter is working by measuring the voltage of your ICE car battery or the batteries in a flashlight. Make certain you are seeing a connection to the battery terminal by setting the meter on ohms and touching both leads to the same terminal. If someone has sprayed a conformal coating (something like clear coat) on the terminals you might not be able to make a connection.

I am interested to hear what you find when you figure it out.


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## Boulder Hybrids (Jan 30, 2013)

Here's what I get with the recent shipment. Makes no sense that they are all dead. Is there some kind of internal fuse in the module?
http://youtu.be/fmXiUSWy3kQ

This is what I get with my prior shipment; which is what I would expect.
http://youtu.be/bz_GwZ5-S9s


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## dougingraham (Jul 26, 2011)

Boulder Hybrids said:


> Here's what I get with the recent shipment. Makes no sense that they are all dead. Is there some kind of internal fuse in the module?


I watched a teardown video somewhere on youtube where the guy dismantled one of those modules. There could be a fuse but I don't remember seeing one. In fact because of the center tap there would have to be two fuses to see the results you are seeing. And the only other thing I can think of is the meter is not reading correctly. I know it seems unlikely but I have seen this happen before that a person was certain their meter was working and it was not. In the video when you connected the leads I saw it glitch to 0.3 and then drop back to 0.0 which seems a little off.


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## Boulder Hybrids (Jan 30, 2013)

I wish it was my meter...I move the meter probes to my older modules and they test fine. The problem is definitely in the newer set of modules. Does not make sense to me.


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## eldis (Sep 3, 2013)

Boulder Hybrids said:


> I wish it was my meter...I move the meter probes to my older modules and they test fine. The problem is definitely in the newer set of modules. Does not make sense to me.


Try to use some current limiting power supply to get something in. 0.0V can only mean dead short or open contact. With a power supply you should be able to see more.

PS: if they would go through hell, you should be able to see it (or smell it) on them.


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## dougingraham (Jul 26, 2011)

Boulder Hybrids said:


> I wish it was my meter...I move the meter probes to my older modules and they test fine. The problem is definitely in the newer set of modules. Does not make sense to me.


Check the resistance. If it is open circuit then there probably are blown fuses in the modules. If you see some resistance I agree that you should try to put some charge into them with something like a bench power supply. Set the current limit to a few hundred ma and open circuit voltage to 8 volts. When the module voltage gets up over 6 volts you can turn up the current to whatever you can do.

Don't let them sit at zero volts. The copper current collectors go into solution over the next month and that isn't recoverable. The longer you wait the less capacity will remain.

If you have the option to return them you should.

Good luck!


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## Duncan (Dec 8, 2008)

Hi
I have some knackered cells - none of them read zero -

Is it possible that you have your meter set for AC??


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## lithiumlogic (Aug 24, 2011)

I saw a video on EVTV where a very determined Youtuber spent several days cutting one of these modules open like an oversized can of spam, to get the raw cells out for his Ebike project. There's no fuses or BMS inside, so it looks like these cells have been overdrained to the point where copper shunts shorted them out. Should that show up on the voltmeter as a very low impedence connection if you set it to measure resistance across the terminals?


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## dougingraham (Jul 26, 2011)

lithiumlogic said:


> There's no fuses or BMS inside, so it looks like these cells have been overdrained to the point where copper shunts shorted them out.


There are no obvious fuses but the internal connections could be designed to open in a short circuit situation just like the little wires to each cell of a Tesla pack.



lithiumlogic said:


> Should that show up on the voltmeter as a very low impedence connection if you set it to measure resistance across the terminals?


There should be some resistance indicated if it is an internal cell short. There should also be some resistance if the cells have been deliberately drained to zero for shipping? If that is the case they might be recoverable.

Thinking more about this if someone decided sparks were fun they could have used something like jumper cables across the terminals of a cell. I have seen two outcomes with LiPo cells when this happens. First is you get sparks and then one of the inter cell connections opens (fusing current is reached). The second is that a cell goes into thermal runaway and the pack ends up in the driveway. If I were designing modules like these I would have some sort of fusing mechanism in the cell to prevent a fire. Unfortunately, since there is no easy access to the cell internals this will be difficult to fix if the case.


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## pdove (Jan 9, 2012)

Sounds like you got screwed to me Paul.

They just lied to you and never checked them or they checked them months ago when they got the car and then some parasitic load in the vehicle drained them.

Send em back.


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## Karter2 (Nov 17, 2011)

Your best logical option is to push for a refund.
But from an educational point of view it would be useful to find out how there can be 0 volts on these cells/pack.
It just does not sound logical ?
See if you can retain a few cells for "autopsy" inspection ?


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## pdove (Jan 9, 2012)

Karter2 said:


> Your best logical option is to push for a refund.
> But from an educational point of view it would be useful to find out how there can be 0 volts on these cells/pack.
> It just does not sound logical ?
> See if you can retain a few cells for "autopsy" inspection ?



Why would this not be logical? Early on a guy did that to his Tesla by putting it in storage for three months. The electronics ion the car drained it to zero. Once you zero a lithium battery is won't usually come back it shorts out internally.


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## Karter2 (Nov 17, 2011)

Not logical or realistic for all cells to go to exactly 0.000 volts.
It's either a dead short, or an open circuit.... On each cell !??


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