Use of Nissan Leaf battery in Solar installation.

Thanks for the feedback.

Now I am just sitting at the office watching the battery pack charge.
This morning it was 10% SOC, and now it is 80%SOC(14:00).. should reach 100%SOC by 16:00.
It works flawless and automatic, no need to human input.

If i can get my hand on one more battery pack I might consider expanding.

I assume you are watching capacity on the battery pack - will be interesting to see at what rate it degrades. Yet another good reason to add more storage capacity than needed eh?

I believe the BMS is talking to the Sunny Island via the CAN bus, so it is aware of the SOC of the battery bank, and likely will not drain it down below a certain SOC/Voltage. There is a point of diminishing returns, there isn't much point in having a lot more KW of storage than what the PV array can produce in a day or two... The sun will come up tommorow (bet your bottom dollar, "Annie" ) and resume charging. On the other hand, if you look at winter solar production and several overcast/cloudy days, more storage could be used, but for those few days, it's probably more economical to buy grid power. It's a balancing act, try to be self sufficient to eliminate dependency and cost of grid power, versus the cost of extra battery storage.

hill said:

This is a very slick set up. I'd imagine several will start doing something similar. I hope Nissan doesn't jack up the price on their pack, to slow such projects down.

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This is a used pack, Nissan won't sell you a leaf pack without a leaf to go with it!

Yes this was a used battery pack, 3 years old.
Probably SOH at 80% already.

Today i charged 14KWH in to the pack.
Remember I only use 42 out of the 48 modules that comes with the battery pack.

Also, I only cycle the battery between 3.7V and 4.1V.
As Norway is quite cold, keeping the batteries around 25`C or below should not be difficult.
You have all seen the movie Frozen, right

Last few days they start off at 15`C in the morning and end up at 22`C in the afternoon.
This should be good conditions for a long lifespan.
Besides, now that i have the inverter and BMS i can easily change battery modules in a few years.

There are plenty of Leafs sold as "Parts only" for cheap.

mitch672 said:

I believe the BMS is talking to the Sunny Island via the CAN bus, so it is aware of the SOC of the battery bank, and likely will not drain it down below a certain SOC/Voltage. There is a point of diminishing returns, there isn't much point in having a lot more KW of storage than what the PV array can produce in a day or two...

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I agree with these points and understand them. My question was more on the line of how fast the capacity of the battery will actually degrade (all of them do). I somehow doubt the Leaf battery aging models will fit exactly - if they do then it would be like a full discharge each day (so, consider that 70 miles/day or approx 25K miles/year?) But is the temperature management in this case at all comparable to the Leaf use case?

Knowing how quickly the capacity will (or won't) degrade in this configuration could have significant impacts on calculating ROI for the solution.

"offpist" stated he payed about $2K for the pack. i just watched one sell on eBay for about $2,300 used, so there is your used pack cost, with BMS and not deep discharging/overcharging it's likely to last a number of years

Wow, this is phenomenal work!!!! You are truly green now! :mrgreen:

we don't have solar on our house yet, but hope to have it in the near future...however I would be more interested if there is a way to plug in our house into LEAF and use it's battery pack as a back up if the power goes out to power our AC( or gas furnace in the winter),TV,Lights.

I remember seeing Nissan showing similar concept, wonder if they made any progress on it? Or how would one go about making it into DIY project?

="JeremyW"... Nissan won't sell you a leaf pack without a leaf to go with it!

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Nissan will, but only if you already own a LEAF.

But Nissan says it will require a used battery pack in exchange, and only give you a ~$1,000 trade-in value for it (which seems to be way below current market price) for that used battery pack.

I wonder what Nissan will do when the first LEAF owners demands a replacement pack purchase, without giving Nissan back their OE battery pack?

edatoakrun said:

I wonder what Nissan will do when the first LEAF owners demands a replacement pack purchase, without giving Nissan back their OE battery pack?

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They won't sell them one, simple as that. The terms of the sale dictate they give the old pack up.

JeremyW said:

edatoakrun said:

I wonder what Nissan will do when the first LEAF owners demands a replacement pack purchase, without giving Nissan back their OE battery pack?

Click to expand...

They won't sell them one, simple as that. The terms of the sale dictate they give the old pack up.

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Interesting. Then I wonder why they bother with the whole "$1K credit for old pack." Why not just reduce the cost of the transaction by $1K and call it a replacement/upgrade only offer. Seems like some sort of marketing baloney going on there....

JeremyW said:

edatoakrun said:

I wonder what Nissan will do when the first LEAF owners demands a replacement pack purchase, without giving Nissan back their OE battery pack?

Click to expand...

They won't sell them one, simple as that. The terms of the sale dictate they give the old pack up.

Click to expand...

I doubt that Nissan can (legally, in many or most markets) dictate the pack return, given the lack of any such disclosure in the statement Nissan provided and required that lessees/purchasers sign.

But I don't think the question is likely to come up for me, or many others.

By the time I want a replacement pack, I expect I'll probably have other aftermarket options, which will allow me to keep my OE pack, If I want to.

offpist, thanks for sharing. If you have time.... What part of earth do you reside? Are you an EE, or energy consultant, or how did you come about the knowledge and skill to complete this task? Like others, I am interested in the technology and in the future, installing a like project...

I live in Norway, as mentioned before.

The technical solution with inverters optimized for increased self-consumption is already provided by SMA.
Anyone can buy it and connect in their house i guess.

All i did was implement the Nissan Leaf Cells in this system.
And when i found an BMS that could communicate with the Sunny Island then rest was just plug and play really.

I don't have a engineer background, just always been interested in electronics.

offpist said:

I live in Norway, as mentioned before.

The technical solution with inverters optimized for increased self-consumption is already provided by SMA.
Anyone can buy it and connect in their house i guess.

All i did was implement the Nissan Leaf Cells in this system.
And when i found an BMS that could communicate with the Sunny Island then rest was just plug and play really.

I don't have a engineer background, just always been interested in electronics.

Click to expand...

Thank you again. Also presume when you ski, you do so off trail....

Hi.
As i mentioned earlier I was considering expanding with more cells.
So today i took some calls and found a company tearing down a totaled Leaf.
They still had the battery pack laying around..
Actually he had to check if they had thrown it away yet..

So he was like, come and pick it up and you can have it for $400.
Picking it up tomorrow
How great is that.

BUT he did not know the condition of the cells of course, its been laying separated from the car without charging for over a year now. So there is always the chance the pack has been flat for a while and therefore defect.

I will take it apart on the spot and measure cell voltage.
If its really low I will leave it there.

I guess there is no way to measure the voltage without opening the whole thing?

If that works out for you it could be an awesome deal!

Makes me wonder how many Leafs are in junkyards waiting for someone to just ask for the battery....

Oh and another thing.
The manufacturer of the BMS is asking for discharge curves @ different loads to make the calculations of SOC a bit better. Now it is a bit off.

(0.3C, 0.5C, 1C, 3 C, 5C @ 25°C) and temperature (0°C, 10°C, 25°C, 40°C @ 0.5C or 1C ).

Has anyone seen this data somewhere?

If it's not an S model I would love love love the telematics module. I'll pay for shipping and whatever they charge for the module. Maybe even VCM or something else if you can get the parts cheap.

I went to check on the battery pack and the voltage was still 3.88V! So it should still be in good condition, an only $400.

It took me about one hour to take it apart an get it loaded i my company car, an VW caddy maxi.

Now I have fitted a total of 70 modules in my rack.
That should give me about 30 KHW of usable storage.