[Darxus]

What's available that's worth using? What are people picking? Sources? I don't see a thread like this, seems useful to have a summary occasionally.

A few I've seen:

Tesla Model S modules: 3.35Wh/$
LG Chem JH3: 3.22Wh/$
CALB LiFePO4: 2.2Wh/$

 

[MattsAwesomeStuff]

Tesla Model S modules: 3.35Wh/$

These are expensive, and large. The issue with them is that you probably won't be able to fit a large amount of them, so you'll be stuck with a lower voltage.

LG Chem JH3: 3.22Wh/$

I think these are no longer available. They were from Chrysler Pacificas I think? Chrysler yanked the plug unless you actually own a Pacifica.

The great thing about them is that they were small, so you could reach a higher voltage with the available cargo space.

CALB LiFePO4: 2.2Wh/$

These are antiquated and problematic. Generally no one does this anymore. Some EV conversion shop still use them because they can just buy them off the shelf unlike OEM EV batteries, or they still have lots in inventory they're trying to liquidate, but, I don't think any DIYers are using these anymore unless they're locked into their build.

 

[john61ct]

Tesla has been expanding their use of LFP

started out on "China market" only.

Now exported pretty much worldwide.

Partnership with CATL.

 

[Darxus]

MattsAwesomeStuff, so if all of those aren't usable, what would you use?

john61ct, is that something I can get for my own build?

 

[brian_]

LG Chem JH3: 3.22Wh/$

I think these are no longer available. They were from Chrysler Pacificas I think? Chrysler yanked the plug unless you actually own a Pacifica.

I had not heard of a "JH3" cell or module, so I did a quick search...

An LG Chem catalog suggests that JH3 is the "Energy" (rather than "High Energy" or "Power") variant in their range of cells for large energy storage systems. It may not be intended for use in a vehicle, as it is intended for discharge rates under 1C. Based on this catalog, the 7S 63 Ah JH3 module appears to be one of two used in LG Chem's smallest residential energy storage system, the "48 V" RESU3.3. The other RESU models may use more of the same modules in parallel. The catalog shows that stationary ESS and automotive applications are distinct.

Whether this is the same cell construction as used in EVs or not, the JH3 modules being sold by EV West at 3.22 Wh/USD (or USD $312/kWh) is a 7S (26 V) 63 Ah module; it is not the 16S (60 V) 43 Ah module used in the Chrysler Pacifica, and not even built of the same cells. The Pacifica module is designed to thermal management via a bottom plate, but it is not apparent whether or not there is any thermal management provision in the JH3 module, although the general construction is similar. The JH3 module is a recent addition to the EV West website.


At 63 AH, a 98S pack to run near the 360 V typical of current EVs (and thus suitable if using a Tesla or Nissan motor) would require 14 modules, adding up to 275 lb (125 kg) - plus structure, enclosure, wiring, etc - for 22 kWh. That's a relatively small but usable capacity in a relatively light pack, compared to a complete salvaged EV battery.

 

[brian_]

Tesla has been expanding their use of LFP

started out on "China market" only.

Now exported pretty much worldwide.

Partnership with CATL.

Yes, but those modules are neither the Model S modules nor the CALB cells that Darxus mentioned, and are not readily available to DIY builders.

 

[john61ct]

Yes, but those modules are neither the Model S modules nor the CALB cells that Darxus mentioned, and are not readily available to DIY builders.

I was simply responding to MattsAwesomeStuff's silly statement about LFP being "antiquated and problematic"

There is a plethora of most excellent LFP cell makers, and sometimes even the very cheap ones can be good.

All things being equal, they last 10x longer than the usual 3.6 - 3.7V li-ion chemistries

and are 100x safer wrt fire risk (relevant these days)

Their only downside is lower energy density.

 

[MattsAwesomeStuff]

I was simply responding to MattsAwesomeStuff's silly statement about LFP being "antiquated and problematic"

You're right, I was unaware of these new cells ... which aren't available to the DIY market, which is the relevant context anyway.

I think it was Duncan who pointed out that literally every single DIY build that used large format LFP cells that ever reappeared here had multiple failures after a few years, and that literally zero people who'd used OEM batteries has had a failure.

Naturally a casual forum observation is not the strictest of scientific methods, but, regardless of whether it's literally true or just generally, and, seeing as how I haven't heard of anyone using LFPs in years unless they were built around that expectation from years ago, I stand by my assertion that LFPs are antiquated and problematic.

All things being equal, they last 10x longer than the usual 3.6 - 3.7V li-ion chemistries

I think you'd have to fudge your data pretty heavily for that to be true. In DIY EV context, it certainly seems that either all things aren't equal, or, they're massively failure prone.

it is not the 16S (60 V) 43 Ah module used in the Chrysler Pacifica, and not even built of the same cells

My bad, I was too lazy to look it up, presumed these were the cells that were all the rage a year ago that have since fallen off the map.

MattsAwesomeStuff, so if all of those aren't usable, what would you use?

They're usable (except for the ones you can't actually buy anymore). They just come with compromises you have to work around.

In addition to your list, Leaf and Volt packs are still popular, because of their smaller form factors (avoid or be careful with 1st gen Leaf packs, they suffer from degradation issues).

You're generally not going to be able to fit a whole 96s pack into a vehicle not designed around the size and shape of the batteries you pull out of an OEM EV. Like fitting soup cans into a rubbermaid, it's just not going to pack as nicely as the original box. Which means you're not going to get the same top speed or performance out of vehicle as the original. To many DIY EVers, that's perfectly fine. They're not in a racing or performance mindset. They're in a "build a fun car that can quickly reach legal highway speeds and casual driving range."

 

[john61ct]

There is nothing new or (much) better about the Tesla LFP cells, other than the QA regime Tesla is surely imposing on CATL.

Yes size & shape, and cost issues may dictate choosing scrapped EV packs vs new cells bought from the maker direct.

But top notch makers like Winston, CALB, GBS, Sinopoly and A123 (now Lithium Werks / Valence / Super B)

have been producing stellar cells for decades now

and properly coddled they do last 20 years or more of daily use losing hardly any of original capacity.

Even when abused by following data sheet min/max voltage specs, saying 10x lifespan is not hyperbole.

LTO is 10x longer lived again compared to LFP, but also rarely used in DIY sedans.

That data point does not mean the chemistry itself is "antiquated and problematic", that just shows a willingness to make false statements from limited experience.