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Re: Used Leaf Batteries Used for Large Scale Power Storage

Posted: Thu Feb 13, 2014 11:29 am
by edatoakrun
Previous thread on-topic:

Repurposing of LEAF batteries in stationary applications


http://www.mynissanleaf.com/viewtopic.php?f=7&t=15816" onclick="window.open(this.href);return false;

Re: Used Leaf Batteries Used for Large Scale Power Storage

Posted: Thu Feb 13, 2014 12:15 pm
by johnrhansen
Is there an amount of degradation to where the leaf battery pack's loss of capacity levels off somewhat? What would it be? Just trying to find out how long they would last in a stationary application.

Re: Used Leaf Batteries Used for Large Scale Power Storage

Posted: Thu Feb 13, 2014 12:34 pm
by hill
RegGuheert wrote:Nice find! It's good to see that some used EV batteries finding a second life.....snip.....
I guess it's nice .... 16 premature deaths of Leaf traction packs ... unless they were one of yours.
:lol:
.

Re: Used Leaf Batteries Used for Large Scale Power Storage

Posted: Thu Feb 13, 2014 12:42 pm
by RegGuheert
johnrhansen wrote:Is there an amount of degradation to where the leaf battery pack's loss of capacity levels off somewhat? What would it be?
I cannot detect any slowing. One owner lost their fourth bar in about the same time as their second (from the previous bar under similar conditions).
johnrhansen wrote:Just trying to find out how long they would last in a stationary application.
It depends on the application. For PV, the cycling may limit the further life. But for backup storage, you could perhaps keep it at 50% SOC in an air-conditioned space and get many years of life.

Also, let's consider that future batteries may have different (much slower) degradation rates at end of life in their EV role. Further consider that in the future the capacity may be higher at the beginning of life.

Re: Used Leaf Batteries Used for Large Scale Power Storage

Posted: Thu Feb 13, 2014 1:02 pm
by aqn
johnrhansen wrote:Is there an amount of degradation to where the leaf battery pack's loss of capacity levels off somewhat? What would it be?
RegGuheert wrote:I cannot detect any slowing.
A couple of highly coarse data points:
First bar: 16 months/10034 miles
Second bar: 11 months/6479 miles (at 16513 miles)
I hope the accelerating trend does not continue... A casual glance at the "real world losses" tables seems to indicate accelerating timeframe of subsequent bar losses but maybe it was just my skewed perspective.

Re: Used Leaf Batteries Used for Large Scale Power Storage

Posted: Thu Feb 13, 2014 1:39 pm
by dgpcolorado
aqn wrote:A couple of highly coarse data points:
First bar: 16 months/10034 miles
Second bar: 11 months/6479 miles (at 16513 miles)
I hope the accelerating trend does not continue... A casual glance at the "real world losses" tables seems to indicate accelerating timeframe of subsequent bar losses but maybe it was just my skewed perspective.
Accelerating? Given that the first CB is a 15% loss and the second is a 6.25% loss, a casual look at your bar loss seems to suggest a slowing trend, not an accelerating one.

Of course, timing with regard to summer heat makes a huge difference. My capacity was declining steadily over the summer but a few months ago, with the onset of cold weather and battery temperatures at about 2 to 10ºC, the decline stopped dead. I expect it to resume as the weather warms. So, drawing straight lines across seasons isn't useful IME.

Re: Used Leaf Batteries Used for Large Scale Power Storage

Posted: Thu Feb 13, 2014 1:41 pm
by GaslessInSeattle
I'm afraid to say it, but I think the high hopes of using the first generation of Leaf batteries for energy storage are going to be shattered by the reality that these batteries appear to not just be wearing out gradually, but out right failing. A combination of dynamics, mostly heat, is leading to dramatic, accelerated decay. The decline curve is so harsh that I suspect they will be worthless, at least the ones replaced under warranty. they will most likely have to be recycled rather than re-purposed. I figure Nissan has one more real shot at this before the market turns away, hopefully this time, their heat tolerant batteries are actually heat tolerant. Feeling very good about trading in my 2012 loan for a 2012 Lease...likely washing my hands of Nissan in 2015 when the Lease runs out, unless things have really made a turn around with much more range at least as an option and much more durable batteries.

Re: Used Leaf Batteries Used for Large Scale Power Storage

Posted: Thu Feb 13, 2014 2:37 pm
by RegGuheert
dgpcolorado wrote:I expect it to resume as the weather warms. So, drawing straight lines across seasons isn't useful IME.
Agreed. I have concluded that until we get better data from someone with LEAFspy, the best we can do is to look at losses between bars 1 and 2 and between bars 3 and 4, and then only if they occur in the same season. I have only found one such data point::
As an example, consider member "cyellen" who experienced the loss of bars one and two during the summer of 2012 and bars three and four during the summer of 2013:
Bar 1 to 2: 73 days and 1400 miles
Bar 3 to 4: 64 days and 1500 miles
Just one data point (since we don't have much data), but it makes it clear that capacity loss does not slow down with degradation. Does it accelerate? It's not clear, but perhaps.

Re: Repurposing of LEAF batteries in stationary applications

Posted: Wed Mar 19, 2014 8:33 am
by edatoakrun
Given the preceding comments, I expect some of you folks are far too full of um...disinformation RE Leaf battery life to accept this, but you just might want to consider the estimate of typical~75% capacity after 14 years (in European climate conditions, and with a typically lower miles driven per year than in the USA, I would expect).

...Charging to the future

“Affordable and reliable batteries could have a second life in data centres and in the home, starting around 2020,” Nissan’s director for corporate planning, Redmer van der Meer told TechWeek at the launch of GreenDataNet.

Electric cars still have a tiny share of Europe’s car market, but each one holds a battery that can deliver 24kWh of energy. At the end of its life, that battery could be added to a big stack at a data centre, to provide back-up and also power that could smooth the peaks of demand, reducing the data centre’s load on the electric grid.

Van der Meer reckons an electric car will have a lifetime of around 14 years, after which time the battery’s performance will have degraded, but it will still hold around 18kWh. If electric cars take a significant share of Europe’s vehicle market, then there will be a sizeable number of battery modules available – though it will take hundreds of them to power a data centre for any length of time...
http://www.techweekeurope.co.uk/news/eu ... ies-141648" onclick="window.open(this.href);return false;

Re: Repurposing of LEAF batteries in stationary applications

Posted: Thu Mar 20, 2014 12:10 am
by ydnas7
edatoakrun wrote:Given the preceding comments, I expect some of you folks are far too full of um...disinformation RE Leaf battery life to accept this, but you just might want to consider the estimate of typical~75% capacity after 14 years (in European climate conditions, and with a typically lower miles driven per year than in the USA, I would expect).

so the first thought that comes to mind

50% of vehicles will not have 70% battery capacity after 14 years
temperature and distances, nederlands

Why don't people see a forecasted gradual degradation issue as a 50% liklihood of occurance? then look around, and guess who is on the wrong side of the 50%.