Battery Upgrades are very possible

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mux said:
There's been a few distinct changes over time, chemically:
- Pure LMO on the initial packs (e-bike chemistry, essentially), very forgiving on charging/discharging current but very bad cycle life
- Al-doped LMO still on gen1 packs, but late in the game (2013ish?), charges to 4100mV/cell now
- Retuned BMS on gen2, no apparent change in the actual battery chemistry, charges to 4130mV/cell
- NMC on gen3 (30kWh), charging to 4180mV/cell
- Higher nickel content NMC on gen4, Li-HV tricks to get a fair bit of extra capacity by charging further (4220-4224mV/cell)
- Then a set of massive BMS retunes to try to fix rapidgate, mostly by increasing charging speeds at subcritical temperatures
- Then a density increase through slightly thinner packaging/electrodes on gen5 (62kWh) and quite a significant change in the BMS again

Altogether we see about 8 distinctly behaving battery packs through the years. I started off by saying they didn't change things every year, but looking back at this list... yeah, on average every year *something* changed in some significant way.

Mux;
Is there a standardized method of determining the useable energy available as a result of these changes? "Standard" meaning Nissan's (standardized) SOC limits applied under standard testing protocols? From FLA/AGM/SLA(VRLA) background, energy was a amp-hour/voltage calc, but not sure that Li tech is that simple!
 
mux said:
There's been a few distinct changes over time, chemically:
- Pure LMO on the initial packs (e-bike chemistry, essentially), very forgiving on charging/discharging current but very bad cycle life
- Al-doped LMO still on gen1 packs, but late in the game (2013ish?), charges to 4100mV/cell now
- Retuned BMS on gen2, no apparent change in the actual battery chemistry, charges to 4130mV/cell
- NMC on gen3 (30kWh), charging to 4180mV/cell
- Higher nickel content NMC on gen4, Li-HV tricks to get a fair bit of extra capacity by charging further (4220-4224mV/cell)
- Then a set of massive BMS retunes to try to fix rapidgate, mostly by increasing charging speeds at subcritical temperatures
- Then a density increase through slightly thinner packaging/electrodes on gen5 (62kWh) and quite a significant change in the BMS again

Altogether we see about 8 distinctly behaving battery packs through the years. I started off by saying they didn't change things every year, but looking back at this list... yeah, on average every year *something* changed in some significant way.

LOL! I agree with EVERYTHING you said but unless you can tie a Nissan announcement to each change, no one will believe it! :lol:
 
Marktm said:
mux said:
There's been a few distinct changes over time, chemically:
- Pure LMO on the initial packs (e-bike chemistry, essentially), very forgiving on charging/discharging current but very bad cycle life
- Al-doped LMO still on gen1 packs, but late in the game (2013ish?), charges to 4100mV/cell now
- Retuned BMS on gen2, no apparent change in the actual battery chemistry, charges to 4130mV/cell
- NMC on gen3 (30kWh), charging to 4180mV/cell
- Higher nickel content NMC on gen4, Li-HV tricks to get a fair bit of extra capacity by charging further (4220-4224mV/cell)
- Then a set of massive BMS retunes to try to fix rapidgate, mostly by increasing charging speeds at subcritical temperatures
- Then a density increase through slightly thinner packaging/electrodes on gen5 (62kWh) and quite a significant change in the BMS again

Altogether we see about 8 distinctly behaving battery packs through the years. I started off by saying they didn't change things every year, but looking back at this list... yeah, on average every year *something* changed in some significant way.

Mux;
Is there a standardized method of determining the useable energy available as a result of these changes? "Standard" meaning Nissan's (standardized) SOC limits applied under standard testing protocols? From FLA/AGM/SLA(VRLA) background, energy was a amp-hour/voltage calc, but not sure that Li tech is that simple!

Eh, ok, I need to write a long blog about how to determine battery capacity and health, because this is not easy to answer.

First off, also for lead acid chemistries, capacity isn't determined by nominal voltage and Ah capacity, these are quantities with a much more nuanced technical meaning that has outstayed its welcome. An LMO or LCO battery, like Nissan's 24kWh batteries, is at more or less the same voltage for most of its capacity range, so it makes sense to give it a nominal voltage. NCM is more or less a linear slope from empty to full, so what really is the meaning of a nominal voltage? Likewise, ampacity is very dependent on temperature and charge rate - something that is of concern with the Leaf which sees much higher RMS currents than average currents. That's a significant reason - along with air resistance - of why you use 25%+ more energy in winter on a non thermally managed battery.

Nissan also uses a lookup table approach for determining/estimating capacity/SOH/SOC and primarily focuses on internal resistance as a marker of battery health. This means charging and discharging profiles change quite a lot with temperature, SOC and SOH. At moderate temperatures and charge rates, Nissan will allow the 30/40kWh cells to charge up to 4224mV/cell, while in the cold and at high charge rates this limit is much lower, even under 4000mV in some cases. You'll see 15%+ differences in capacity in the exact same battery because of that.

So by one metric, nominally, all 24kWh batteries have the same capacity. But a Canary battery will have considerably less usable capacity in low temperatures and will, as a limitation of the BMS firmware, not quite charge as close to 100% as the Lizard packs.
 
mux said:
Eh, ok, I need to write a long blog about how to determine battery capacity and health, because this is not easy to answer.

First off, also for lead acid chemistries, capacity isn't determined by nominal voltage and Ah capacity, these are quantities with a much more nuanced technical meaning that has outstayed its welcome. An LMO or LCO battery, like Nissan's 24kWh batteries, is at more or less the same voltage for most of its capacity range, so it makes sense to give it a nominal voltage. NCM is more or less a linear slope from empty to full, so what really is the meaning of a nominal voltage? Likewise, ampacity is very dependent on temperature and charge rate - something that is of concern with the Leaf which sees much higher RMS currents than average currents. That's a significant reason - along with air resistance - of why you use 25%+ more energy in winter on a non thermally managed battery.

Nissan also uses a lookup table approach for determining/estimating capacity/SOH/SOC and primarily focuses on internal resistance as a marker of battery health. This means charging and discharging profiles change quite a lot with temperature, SOC and SOH. At moderate temperatures and charge rates, Nissan will allow the 30/40kWh cells to charge up to 4224mV/cell, while in the cold and at high charge rates this limit is much lower, even under 4000mV in some cases. You'll see 15%+ differences in capacity in the exact same battery because of that.

So by one metric, nominally, all 24kWh batteries have the same capacity. But a Canary battery will have considerably less usable capacity in low temperatures and will, as a limitation of the BMS firmware, not quite charge as close to 100% as the Lizard packs.

Thanks for this interesting information - the changes in allowed energy usage of the 24 vrs the 30/40 kWh based on operating conditions makes sense. I was mostly interested in what set of standard conditions Nissan rates that useable energy and did they put more/less "conservativism" in the later (62?) battery designs by "tweaking" those standard conditions - which apparantly they might have with allowable top end voltages - at least from a "rating" standpoint. Which begs the question is there any industry standard when advertizing EV kWh ratings?
 
Nope, everybody is different. And to add to that: basically nobody, including myself, has a good overall knowledge of battery technology (including all relevant factors - chemistry, packaging, management, long-term properties, etc. etc.). Certainly regulators don't know jack ****, and this is something we expect will come back to haunt many EV makers at some point in the future when this knowledge becomes more commonplace and a lot of the currently common - but largely incomplete or mistaken - narrative around batteries fades away.

There isn't a single subgeneration of Leaf batteries that uses the same charge/discharge/capacity parameters. The best I can say is that some tweaks are so minor as to be relatively insignificant, e.g. the voltage cutoff parameters for gen4 and gen5 (40 and 62kWh). You can treat those packs as mostly the same from a voltage management point of view.
 
mux said:
Nope, everybody is different. And to add to that: basically nobody, including myself, has a good overall knowledge of battery technology (including all relevant factors - chemistry, packaging, management, long-term properties, etc. etc.). Certainly regulators don't know jack ****, and this is something we expect will come back to haunt many EV makers at some point in the future when this knowledge becomes more commonplace and a lot of the currently common - but largely incomplete or mistaken - narrative around batteries fades away.

Hopefully guys like you that take a pragmatic approach to solving major EV issues (like rejuvinating Leafs for a second - well deserved - life), AND have the technical background to resolve those tough issues (CAN bridge) will continue help us all make better decisions to push EV proliferation to greater levels. If only you lived in Houston, TX. :mrgreen: - believe me there is a real reason with ERCOT as our electrical energy regulator!
 
mux said:
There isn't a single subgeneration of Leaf batteries that uses the same charge/discharge/capacity parameters. The best I can say is that some tweaks are so minor as to be relatively insignificant, e.g. the voltage cutoff parameters for gen4 and gen5 (40 and 62kWh). You can treat those packs as mostly the same from a voltage management point of view.

Are there any upgrade combinations that are problematic in a Leaf? I've been considering upgrading an older Leaf at some point (probably 2013-2015 to 40kWh) and I always assumed everything would be 100% compatible, even though I have heard of slightly different voltage range levels on the various batteries, etc.
 
goldbrick said:
Are there any upgrade combinations that are problematic in a Leaf? I've been considering upgrading an older Leaf at some point (probably 2013-2015 to 40kWh) and I always assumed everything would be 100% compatible, even though I have heard of slightly different voltage range levels on the various batteries, etc.

None reported so far. I've done the following combinations:
ZE0 2010 24kWh
ZE0 2011 30kWh
ZE0 2012 40kWh
ZE0 2012 40kWh
ZE0 2013 24kWh
ZE0 2011 30kWh
ZE0 2011 24kWh
Env200 40kWh
Env200 40kWh
Env200 40kWh
AZE0 2015 40kWh
ZE0 2012 24kWh
AZE0 2016 40kWh
ZE0 2011 24kWh
ZE0 2011 30kWh
AZE0 2013 40kWh
AZE0 2015 40kWh
Env200 40kWh
AZE0 2014 40kWh
AZE0 2016 40kWh
AZE0 2016 40kWh
AZE0 2013 62kWh
AZE0 2014 62kWh
Env200 40kWh
AZE0 2014 38kWh
ZE0 2011 40kWh
ZE0 2012 40kWh
AZE0 2014 30kWh
ZE0 2012 30kWh
ZE0 2012 40kWh

Only thing is that the 62kWh upgrade requires more effort, spacers, skidplate and stiffer rear springs!
 
Thanks! I really appreciate all your contributions here and of course the CAN-bridge which has enabled an entire cottage industry.
 
Dala, you are an inspiration. I will gladly support your environmentalism. What is the best way to send you money, meaning the least middle-man fees ?

----
You mentioned in your video a couple failed upgrades. Care to share details that might help others avoid pitfalls ?
 
Dala, I left a comment for you in the YouTube video comments. From one business person to another, I hope you find it useful as you seem like a genuinely good person who deserves to make an honest living from a viable business
 
If anyone is in the market for a crashed 2019 SL Plus with a good battery my totaled SL plus goes up on auction next Friday. State Farm now owns it. https://www.copart.com/lot/57864930/salvage-2019-nissan-leaf-s-plus-fl-punta-gorda

If I remember correctly the SOH was about 96% last time I checked about 2 months ago
 
SageBrush said:
Dala, you are an inspiration. I will gladly support your environmentalism. What is the best way to send you money, meaning the least middle-man fees ?

----
You mentioned in your video a couple failed upgrades. Care to share details that might help others avoid pitfalls ?

I like Patreon, since it introduces a way to give something back. As a company in Finland you can't take donations without a permit, so a Patreon account is better since you get technical content via that.

I took on an upgrade where the battery was flooded with water, and had to be scrapped. Another upgrade had modules which were soo swelled that they weren't suitable for repurposing (taxi vehicle). Especially the rear stack can be messed up on 30kWh vehicles!

alozzy said:
Dala, I left a comment for you in the YouTube video comments. From one business person to another, I hope you find it useful as you seem like a genuinely good person who deserves to make an honest living from a viable business

Thank you :)
 
Well, there you go, that's a big reason why muxsan has been able to grow towards sustainability. Sustainability isn't just a statement towards the environment; the business itself also needs to endure so its mission can be carried out fully and completely. We're very aware that battery products that we and our colleagues like Dala sell seem expensive. But that margin is necessary; to pay for inevitable mistakes as well as to pay for durable support towards the customers and these vehicles.
 
Mux,

Think we could find a US shop to install your range extender packs? Then its just a pack export/import?

Any future evolution of the product coming as the chemistry improves?
 
Right now, we don't have the production capacity to expand beyond a few installers in Europe. US installations aren't happening this year.

And yes, we're very much looking towards new cells. This won't happen super-soon, but definitely still in 2021. We're very supply-constrained and would like to shift to a new supply before shipping out (very) large amounts overseas.
 
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