Best cells donor for 2012 SL

Curious what is the youngest battery I can theoretically find for swapping cells for my 2012 Leaf SL, in terms of geometry? Didn't find exact answer to that, but my impression is that should be up to mid-2016 S w/24 kWh battery - 30 kWh cells are different in size. Oldest (but better than mine) cells I should get is Apr`2013 when Nissan changed chemistry of the battery so it deteriorates slower.
Here I'm not talking about bars, SOH etc, only dimensions.

There is way too much variation in cell degradation to simply go by manufacture date.

Of course I would look for better option from this POV, but I need to limit my search somehow.

Limit your search to those offers that report Ahr

Did you see at least one of such on CL/ebay/FB? And what would be your recommendation for lowest AHr?

My point is that if the Ahr is not published you are gambling if the cells are more than a year or two old

Thanks for the advice SageBrush. I never met ads with ahr posted, but I'm only looking for couple of months. E.g. one of good options (but still too pricey) here doesn't mention ahr: https://www.ebay.com/itm/Nissan-leaf-Lithium-ion-Battery-Pack-solar-or-swap-2015-12-bars-super-low-miles-/303221371149

I wonder if there is a way to get battery status from dismounted battery.

Andrey said:

Thanks for the advice SageBrush. I never met ads with ahr posted, but I'm only looking for couple of months. E.g. one of good options (but still too pricey) here doesn't mention ahr: https://www.ebay.com/itm/Nissan-leaf-Lithium-ion-Battery-Pack-solar-or-swap-2015-12-bars-super-low-miles-/303221371149

I wonder if there is a way to get battery status from dismounted battery.

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If they can prove 12 bars when removed, as claimed, that is the best you can expect.

So take their promise in written form to have argument in case it's not there? Good point, except I don't know if it works for ebay/CL.
Anyway, still have range for geometrically compatible cells from 2013.05 -- 2016.6. Anymore thoughts here?

BTW there's a NZ company that promised to release in next 2 weeks that will make possible pairing even 30kwh battery to gen1. When they post price and availability I'll post here, might be good alternative for swapping cells. They also have pairing tool bundled.

Andrey said:

So take their promise in written form to have argument in case it's not there? Good point, except I don't know if it works for ebay/CL.
Anyway, still have range for geometrically compatible cells from 2013.05 -- 2016.6. Anymore thoughts here?

BTW there's a NZ company that promised to release in next 2 weeks that will make possible pairing even 30kwh battery to gen1. When they post price and availability I'll post here, might be good alternative for swapping cells. They also have pairing tool bundled.

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You are covered by the eBay Money Back Guarantee if you receive an item that is not as described in the listing.

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If the AH of the cells or modules doesn't correspond with 12 bars (>85% of new) , you can apparently get a free return for refund.

The problem with using 30kwh modules is that you are more likely to get bad or degraded ones.

I was just going to buy a whole 40kwh battery and force fit, mix, match bits and pieces till it will fit into the 24kwh batt box.
In a year or 2 the worst case scenario should be a 11 bar 40kwh batrery.

LeftieBiker said:

The problem with using 30kwh modules is that you are more likely to get bad or degraded ones.

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How so ?

Even if you think that 30 kWh cells are no better than 24 kWh cells, they are not as old.
I remember QC problems with the pack early in the 30 kWh run but we are talking here about packs removed from cars that have been totaled.

SageBrush said:

LeftieBiker said:

The problem with using 30kwh modules is that you are more likely to get bad or degraded ones.

Click to expand...

How so ?

Even if you think that 30 kWh cells are no better than 24 kWh cells, they are not as old.
I remember QC problems with the pack early in the 30 kWh run but we are talking here about packs removed from cars that have been totaled.

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There are two kinds of problems with 30kwh packs: bad cells mainly (but not entirely, I think) in the early builds, and actual rapid capacity loss. Picture this scenario: a 2017 Leaf loses 3 or 4 capacity bars. It gets the BMS update, and the lost bars are "restored" but will be dropping again soon because the cells have actually degraded quickly. In the meantime the car gets totaled, and the pack is sold as a "12 bar" pack, when in fact it is more like 8 or 9 bars...

LeftieBiker said:

SageBrush said:

LeftieBiker said:

The problem with using 30kwh modules is that you are more likely to get bad or degraded ones.

Click to expand...

How so ?

Even if you think that 30 kWh cells are no better than 24 kWh cells, they are not as old.
I remember QC problems with the pack early in the 30 kWh run but we are talking here about packs removed from cars that have been totaled.

Click to expand...

There are two kinds of problems with 30kwh packs: bad cells mainly (but not entirely, I think) in the early builds, and actual rapid capacity loss. Picture this scenario: a 2017 Leaf loses 3 or 4 capacity bars. It gets the BMS update, and the lost bars are "restored" but will be dropping again soon because the cells have actually degraded quickly. In the meantime the car gets totaled, and the pack is sold as a "12 bar" pack, when in fact it is more like 8 or 9 bars...

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That is complete conjecture, but if it helps one can always avoid 30 kWh packs from the first 6 months or so of the 30 kWh model run. It also helps that OP is buying modules so his risk is diluted considerably since a bad module probably leaves the others healthy.

That is complete conjecture, but if it helps one can always avoid 30 kWh packs from the first 6 months or so of the 30 kWh model run. It also helps that OP is buying modules so his risk is diluted considerably since a bad module probably leaves the others healthy.

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It isn't "complete conjecture." We know that a significant number of 30kwh packs lose capacity quickly and that it is not always restored by the BMS update - it's real capacity loss. Packs with this issue likely have more than "a" bad module. Finally, saying that the risk is diluted doesn't much help someone who is looking for a set of ALL good modules. In any case, the OP is looking for cells compatible with a Gen I pack, and 30kwh cells are not.

LeftieBiker said:

Packs with this issue likely have more than "a" bad module.

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Any evidence to back up your statement ?

SageBrush said:

LeftieBiker said:

Packs with this issue likely have more than "a" bad module.

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Any evidence to back up your statement ?

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As it usually is with me, it's a case of what I remember - which is that people with capacity bar loss and a 30kwh pack don't usually have bad cells showing on LeafSpy. Those with defective cells do, several bars lost don't seem to. There is always the chance that I'm wrong - or that anyone else is wrong - but my record on characterizing the various packs is good. For quite a while I was virtually alone in doubting that Nissan's BMS "update" would solve the capacity loss problem for all of the 30kwh packs. Now that people who have has the update are re-losing bars again, it looks very much Nissan was taking advantage of a few buggy LBCs to claim a cure for a larger problem. That is why I only recommend that people buy a 30kwh Leaf if they have substantial evidence that the specific car they are interested in has a good pack.

On a closely related note, I think I have a name for the 30kwh packs. I originally, when they started dropping bars left and right, called them "Lettuce Packs" but it now appears that they range from Canary pack bad to Lizard pack good. So what do you folks think of... "Mystery Pack"? "Or maybe "Roulette Pack"?

^^ lol

I agree with your statement that LeafSpy can identify bad cells, although I'm less confident of your memory when it comes to specifics of the rapidly degrading packs after the software update. You also have no way of knowing how frequent that problem is, presuming it exists.

I know that makes me sounds like the Seattle guy but there is a difference: we have a survey that included hundreds if not over a thousand of Gen 1 packs to conclude a lot about their degradation; in the case of the 30 kWh packs we might have a handful. and IF my memory serves they occurred in the first 6 months of production so there could well be confounding factors at play.

That is just no where near enough to post a sweeping generalization.

The 30kwh degradation problem has persisted through the 2017 model year. It definitely doesn't occur with all of the packs, but it does occur in both years.

Andrey said:

I wonder if there is a way to get battery status from dismounted battery.

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https://evsenhanced.com/products/leaf-battery-capacity-test-loop/