Batteries from a Leaf?

[Redbearded]

Hi all,

So I'm looking at putting some massive power in my new rolling home and one of the possibilities I'm considering is using the batteries out of a Nissan Leaf... They have 24KWh of power per car and I figure that if I get a pack out of a wrecked car I'll have up to ~18KWh available if I use the whole pack (I'm still debating if I want/need this much, and if I want this much weight in the trailer). The cells are discussed here and look to be about 8.4lbs each and there are 48 prismatic modules in the whole pack, which is just over 400lbs of batteries, lol. I'm pretty sure that will be overkill for me and my needs, but the price is hard to beat for a power source that potent (the whole pack is ~$2-3000). There is a family installing this setup in an old GMC bus on youtube which is where I 'borrowed' the idea from. They have it set up with for a 48 volt system which if I used all the cells would most likely copy. For a 48V system this would give 375Ah, at 24V it would be 750Ah, and at 12V 1500Ah... 


Previously I was looking at using some of the LiFePO4 batteries for my trailer, but given the layout of these cells, and the price point for the available power it seems like a simple choice. What do you all think? Any reason to not go with this kind of a setup? I also have a guy fairly local to me who tears the leaf packs apart and puts them in some smaller EV applications.

The plan for my setup at this point is to go with about 12-1300W solar (4 household panels with some mild solar tracking (still in the rough design stages)) and set the system up so I never have to plug in to charge. I'm actually thinking about not even installing a charger and just leave the system to be self sustaining from the solar alone. I would prolly go 48V for the battery and put in a 12V converter to provide for the trailer vow voltage system. Then install a nice big inverter that has high efficiency to power all the everyday goodies. Plus there are some A/C systems that run off 48 volts which may be interesting down the road

As always, thoughts and feedback are always appreciated!

 

[Van-Tramp]

The big question is, what are you doing that you feel the need for that much battery capacity? Considering the cost, and the over-complication of what normally is a simple idea (solar + battery) is there something pushing you this way beyond “because I can”?

 

[Weight]

Here are some photos following a fire caused by Chevy Volt batteries jury-rigged into a golf cart. In the thread there are many false ideas as to the reason the batteries exploded. Please do not use any but LiFePo, (lithium iron). http://www.rvnetwork.com/topic/130830-more-of-our-fiver-fire-photos/

 

[MrNoodly]

Here's a video about guys converting an old Honda to electric drive using, among other things, the battery pack from a Leaf. You can see it's a large T-shaped thing. That could affect where you could fit it.

 

[Headache]

I like a lot of power having the comforts of home. I also like creative use and stuff that isn't built with a credit card. However, make sure you know what you are doing and know those batteries better than you know your family. Your life as well as others depends on it.

In full disclosure I'm an AGM kind of gal. I'm lazy that way.

 

[John61CT]

I would used the big prismatic LFPs.

Much lower risk of thermal runaway (Boom Bad!), much less kludgey DIY engineering, nice standard 12 or 24V output, and cared for properly, **much** greater longevity.

The day will come when open source + OTS hardware control units will be out there long enough to make these EV packs plug and play, but I think a ways away yet.

 

[highdesertranger]

I agree with Headache. you better know what you are doing. highdesertranger

 

[Headache]

If the OP is up to the task(short of being an electronic engineer) or has unlimited access to people that know how to do it(for e.g. the Seattle Electric Car Club is pretty much all DIYrs) then by all means spin that bad boy up.

It's super awesome to have that brainstorm and think how happy you'd be to make that happen. It's a grand sense of accomplishment. I'm not going to scare you out of doing it nor am I going to just assume I know you and therefore project my beliefs onto you. That's BS.

Instead I hope you have that kind of knowledge or are self aware enough if you don't because otherwise we may be nominating you for the Darwin Awards and I don't want to do that.

 

[John61CT]

Someone with the prerequisite skills or mates would not be asking here based on YouTubes.

Plenty of DIYers are game to do this sort of thing, and most won't die as a result.

Doesn't mean that 99.99% of them aren't rolling the dice!

It truly does require solid specialist engineering-level knowledge to end up with a result that is actually safe.

 

[Headache]

Don't say that around the electric car club guys.   They have no trouble setting the ass-u-me crowd straight.  Seen it.

 

[Redbearded]

My education is as a mechanical engineer, and I will not be doing anything that I will not have vetted fully. I may even just buy one cell of a leaf and short it out to see how actually dangerous they actually are, or find someone who has done that testing before. I have access to a few buddies who are electrical engineers so I'm not too worried. If there is real danger I'll just go back to the LiFePO4 setup, but from what I'm reading the chemistry used in the Leaf batteries is muck less volatile than the Tesla chemistries and there are fewer cells so the chance of a cascade failure is less due to fewer parts. Obviously more research need to be done and will be, but I am mainly concerned with broad brushstroke knowledge and concerns people have. I know I wouldn't want to use something like used 18650's as that has too many uncontrolled factors and cell balancing would be problematic without huge investments of time and money.

 

[John61CT]

Yes that last is IMO a purely hobbyist / science project approach.

If you do get it sorted (EV pack safely used as House bank) you'll also want to go into "production mode" with a new or only slightly used set, as their overall cycle longevity is a very small fraction of LFPs.

IMO 10%, maybe 20%.

That may well improve as we learn more on how to care for them for longevity.

We're still only under ten years on experimenting with LFP.

 

[ftrr]

This guy and his family have done what you are talking about in a vintage bus. Beginning From This Morning on YouTube. https://www.youtube.com/channel/UC-xTux7NNRrOTE_74WbU5cg I am also interested in using leaf modules in a solar system. He did a 48V system.