[Mitchy]

Haven't seen much in terms of information for either the LG E71A or E78 cells regarding their Pulse discharge capability ~3sec.
Has anyone had any experience with either of these in a 96s 3p config for a LDU Sport unit?
Trying to determine what cell is reasonable for either a single Sport LDU or Sport LDU/Small Front Drive unit combo (Basically P-D config)

...Yes I know Tesla Modules.. But I'm trying to stay under 80kWh Capacity. Other unicorn cells like the Pacifica ones aren't even an option.
Any other high discharge options would be nice, but didn't want to make this post as your typical 'What cell should I get'

 

[D&VsEVJeep]

Hi Mitchy,
We will be testing our LG E71A cells soon to get some performance data. We also gave some cells to Orion for their BMS but I haven't received anything back from them yet. I can tell you that from our data logging in our Mustang Mach-E, full acceleration shows more than 650A... That is with the 4p extended range configuration so more than 162.5A per cell...

Hope this helps.

 

[D&VsEVJeep]

BTW...Battery Hook-up is only recommending 300A for a 10s pulse in the 4p configuration so 75A per cell...

LG 28.8v 8.5kWh 8s Lithium Ion EV Module - $100/kWh

This is one of the best values you will find. Comes out to just $100/kWh. These modules are made with LG LGX cells and are just absolutely perfect for powerwall, forklifts, golfcarts, EV, and many other projects. The modules came out of VERY LOW mileage electric vehicles and are testing amazing...

batteryhookup.com

 

[remy_martian]

Hi Mitchy,
We will be testing our LG E71A cells soon to get some performance data. We also gave some cells to Orion for their BMS but I haven't received anything back from them yet. I can tell you that from our data logging in our Mustang Mach-E, full acceleration shows more than 650A... That is with the 4p extended range configuration so more than 162.5A per cell...

Hope this helps.

As far as I know, the traction inverters are the same for extended range - the parts catalog did not differentiate back when I looked. You may be hitting an inverter current limit vs a battery limit. Doesn't the extended have a higher pack voltage? Would be interesting to log the non-extended car's max current if you ever get the chance...

Don't forget that the GT Performance model has a larger front motor on the same pack, which may increase the draw beyond the 650A you're seeing.

 

[D&VsEVJeep]

As far as I know, the traction inverters are the same for extended range - the parts catalog did not differentiate back when I looked. You may be hitting an inverter current limit vs a battery limit. Doesn't the extended have a higher pack voltage? Would be interesting to log the non-extended car's max current if you ever get the chance...

Don't forget that the GT Performance model has a larger front motor on the same pack, which may increase the draw beyond the 650A you're seeing.

My point was more that the ER modules/pack has the 4p configuration vs. the 3p configuration mentioned above... At least this is my understanding. I think the voltage is the same, but the capacity is 1/4 lower (3 cells vs 4).

Here is the comparison of the modules from battery hookup:

 

[Mitchy]

The Batteryhookup was what had me worried. I can't see them saying that a 1C pulse discharge is the limit...Maybe in an aircooled config?
It seems a pretty good assumption that most of the Automotive class cells can likely handle 5C discharge for over 10sec. I think even most spec sheets state 3C.
Curious to see what Orion finds with their cell characterization.

My guess is they're somewhere around the E66A, maybe a bit better due to the length.

4P would be great, but for these cells in a 96s config i'm at a bust with weight and space.

From my research for the E78 cells, seems that evshop.eu puts the ID3 modules at 1000A for 3P, so a ~4C discharge rate.

 

[remy_martian]

I read that also as "for your air cooled powerwall", but it is definitely unclear.

 

[brian_]

My point was more that the ER modules/pack has the 4p configuration vs. the 3p configuration mentioned above... At least this is my understanding. I think the voltage is the same...

The standard range Mach E battery (also used in the E-Transit) is 96S 3P; the extended range Mach E battery is 94S 4P... so the extended range actually has slightly lower voltage.

It's just a matter of what modules fit in the battery case:
standard - 8 modules @ 10S 3P + 2 @ 8S 3P (8*10 + 2*8 = 96 S for whole battery)
extended - 10 modules @ 8S 4P + 2 @ 7S 4P (10*8 + 2*7 = 94 S for whole battery)

Here is the comparison of the modules from battery hookup:

View attachment 128880

Assuming that the illustrated modules are from the Mach E, they are only two of the four Mach E module sizes: 28.8V 8.5 kWh 8s is the 8S 4P (larger) module from the extended range battery, while the 28.8V 6.3 kWh 8s is the 8S 3P (smaller) module from the standard range battery.

I think the voltage is the same, but the capacity is 1/4 lower (3 cells vs 4).

Yes, these modules have the same number of cells in series and just different numbers of cells in parallel, but the Mach E packs are not just built of the same number of modules of these two different sizes, so the two packs do not have the same voltage and are not simply in a 4:3 ratio of energy capacity. To deliver the same power, the extended range battery will supply a couple percent higher current due to the couple percent lower voltage.

 

[D&VsEVJeep]

@brian_ I did my calculations from the current draw I was seeing on the OBD in the car... I did not calculate by power. So, my math should still be right. 650A divide by the 4 cells in parallel in the ER pack in our GT is 162.5A per cell... And my "the voltage is the same" was meaning between the two different capacity modules as shown. One with 3P and one with 4P...both at 28.8VDC.

BTW...it was my understanding that the Mach-E's were set up like this:

Standard Pack: 8 modules @ 8S 3P + 2 modules @ 7S 3P
Extended Range: 8 modules @ 8S 4P + 2 modules @ 7S 4P

As far as I know the Mach-E does NOT use the 10S module and I think that is in the transit and F-150... And it would make sense because I have seen the 8S modules packed in the Mach-E pack and I can't imagine they could fit the additional 4S for using 10S modules...

These are 4P 8S modules with the 4P 7S modules up front...

 

[brian_]

@brian_ I did my calculations from the current draw I was seeing on the OBD in the car... I did not calculate by power. So, my math should still be right. 650A divide by the 4 cells in parallel in the ER pack in our GT is 162.5A per cell...

Yes, I agree. As already mentioned, if that's a current limit it may be due to the inverter(s), rather than the cells in the battery.

... And my "the voltage is the same" was meaning between the two different capacity modules as shown. One with 3P and one with 4P...both at 28.8VDC.

Yes, for the modules, rather than the complete batteries.

BTW...it was my understanding that the Mach-E's were set up like this:

Standard Pack: 8 modules @ 8S 3P + 2 modules @ 7S 3P
Extended Range: 8 modules @ 8S 4P + 2 modules @ 7S 4P

No. The numbers of cells in series just don't add up, and even the number of modules is not right for the extended pack. The extended pack has two additional modules, stacked on top of the rearmost set, under the rear seat.
Both of your pack configurations with 8 modules @ 8S plus 2 modules @ 7S would have only 78 cell groups in series - far too few in both cases, with a nominal voltage of only 293 V.

As far as I know the Mach-E does NOT use the 10S module and I think that is in the transit and F-150... And it would make sense because I have seen the 8S modules packed in the Mach-E pack and I can't imagine they could fit the additional 4S for using 10S modules...

The 10S modules (the larger ones of the standard pack) are only 3P, so they're 30 cells long. This is slightly shorter than the 8S modules of the extended pack which are 4P, so they're 32 cells long. There is a bit of empty space down each side of the standard pack case because both cases are the same width. There are no 10S 4P modules because they would be 40 cells long and indeed would not even come close to fitting in the battery case.

The E-Transit uses exactly the Mach E standard range battery - the case isn't even the right shape or width for the vehicle, it's just stuck under there with an enormous framework to hold it below the frame rails because it's the only battery Ford has in production which is suitable, and the E-Transit isn't worth building a special pack for.

The F-150 Lightning battery is probably unrelated - I haven't seen meaningful details. The capacities have been announced (98 kWh for the standard-range versions and 131 kWh for the extended-range), but without knowing the voltage the configuration is a wild guess. Using the same cell in 4P would make these high and very high in voltage. The Lightning isn't even supposed to use LG Chem cells - Ford announced a joint venture with SKI a year ago for these batteries.

These are 4P 8S modules with the 4P 7S modules up front...

View attachment 129009

That's the first three rows of modules in an extended pack - two rows with one pair each of the big 8S 4P modules which fill the width of the case for most of the length, and the pair of shorter 7S 4P modules in the front row because the case is rounded off at the front corners (front is to the right in the photo). If the photo showed the rest of the pack, you would see two more rows of 8S 4P modules in this bottom level plus another pair of 8S 4P modules on top of them.

 

[brian_]

Another way to think of this...

BTW...it was my understanding that the Mach-E's were set up like this:

Standard Pack: 8 modules @ 8S 3P + 2 modules @ 7S 3P

A 7S 3P module would have 21 cells, but no LG Chem module has an odd number of cells, because of the way the cells are retained in pairs by the polymer frames. Also, pair of 21-cell modules would be far too short to make sense.

The standard pack does indeed use 8S 3P modules, but only in the front row where the 24-cell length is required to fit with the rounded corners. A 7S 4P module (so 28 cells per module) fits in that front row, so even shorter modules down the whole length of the pack would make no physical sense.

8 modules @ 8S + 2 modules @ 7S = 78 cell groups in series, or roughly 290V. With a 3P configuration of 71 Ah cells that would be 290 V * 213 Ah = ~62 kWh, not the real nominal capacity of ~70 kWh.

The actual configuration of 8 modules @ 10S 3P + 2 modules @ 8S 3P has 96 cell groups in series of 284 Ah each, for 360 V * 213 Ah = ~77 kWh nominal and 68 kWh usable, assuming the 71 Ah cell rating is correct.

Extended Range: 8 modules @ 8S 4P + 2 modules @ 7S 4P

These are indeed the module sizes, but there are 12 modules in the extended pack, not 10, because of the extra layer of two modules at the back.

8 modules @ 8S + 2 modules @ 7S = 78 cell groups in series, or roughly 290V. With a 4P configuration of 71 Ah cells that would be 290 V * 284 Ah = ~82 kWh, not the real nominal capacity of ~91 kWh. The missing capacity is due to the the two missing modules.

The actual configuration of 10 modules @ 8S 4P + 2 modules @ 7S 4P has 94 cell groups in series of 284 Ah each, for 353 V * 284 Ah = ~100 kWh nominal and 88 kWh usable, assuming the 71 Ah cell rating is correct.

 

[D&VsEVJeep]

@brian_ Not trying to argue with you...just wondering then how they are doing the 3P configs...I have not seen or taken apart any 3P modules, in person...so I am just guessing here... Have you seen any actual modules or any pictures? Did Munro show any images of their cell pair slices from their teardown? From their video, the 3P uses the same busbars as the 4P and the welds look the same which suggests to me that for the 3P version they use a different frame for the single cell "pair" which has a spacer in the 4th place instead of a cell and that weld only attaches one cell tab to the busbar instead of two.

But then again, it looks like the welding is different from my 4P modules vs. the modules Sandy had... But even then, the config doesn't add up unless there are blank spacers in place for the 4th cell. In the Sandy image below (with the 3P module), we can see the different tab materials by their color...the lighter silver is the + and the darker silver is the -. Here is a picture of a actual cell pair on my desk and you can maybe see this:

From my 4P modules:

From the Munro Video:

There is no way you can have the config above without spacers for the 4th cell.

So, just by removing the 4th cell in the 3P modules, then the 4P and 3P modules would be exactly the same physical size which means all the pack aspects are the same between the two...which is what you want in a mass production environment. The packs would be physically exactly the same only with some cells missing from the 3P modules...

So, despite your math and a lot of assumptions, I would still believe that the 3P module is the same as the 4P module with a spacer in place of the 4th cell...

BTW...back to the original premise... I think all the dual motor Mach-E's come standard with the ER pack which would mean the 4P modules which means you can have the higher current possible, which would make sense for dual motors.

 

[brian_]

@brian_ Not trying to argue with you...just wondering then how they are doing the 3P configs...

No argument - just a discussion, or perhaps a debate.

@brian_...I have not seen or taken apart any 3P modules, in person...so I am just guessing here... Have you seen any actual modules or any pictures? Did Munro show any images of their cell pair slices from their teardown? From their video, the 3P uses the same busbars as the 4P and the welds look the same which suggests to me that for the 3P version they use a different frame for the single cell "pair" which has a spacer in the 4th place instead of a cell and that weld only attaches one cell tab to the busbar instead of two.

But then again, it looks like the welding is different from my 4P modules vs. the modules Sandy had... But even then, the config doesn't add up unless there are blank spacers in place for the 4th cell. In the Sandy image below (with the 3P module), we can see the different tab materials by their color...the lighter silver is the + and the darker silver is the -. Here is a picture of a actual cell pair on my desk and you can maybe see this:

View attachment 129013

From my 4P modules:

View attachment 129011

From the Munro Video:
View attachment 129012

There is no way you can have the config above without spacers for the 4th cell.

So, just by removing the 4th cell in the 3P modules, then the 4P and 3P modules would be exactly the same physical size which means all the pack aspects are the same between the two...which is what you want in a mass production environment. The packs would be physically exactly the same only with some cells missing from the 3P modules...

So, despite your math and a lot of assumptions, I would still believe that the 3P module is the same as the 4P module with a spacer in place of the 4th cell...

Munro's teardown was the standard pack. They tore one module right down to the cell level, but didn't spend much time on the cell connection details. The construction of the stack in cell pairs is the same regardless of how many are connected in parallel, although of course the cells must be placed in the correct orientation (positive and negative at the appropriate ends) for the configuration.

There are no spacers or empty slots in the cell stack to make a 3P configuration - that would be a ridiculous waste of space (although Tesla did that in low-capacity Model 3). In a production vehicle you certainly do not want 1/4 of the battery module volume to be empty wasted space, because space is at a premium. The Mach E extended pack is much larger in volume than the standard pack, due to the extra height at the back under the rear seat that holds the extra two modules needed to have 376 cells instead of the standard pack's 288 cells; those cell counts are as explicitly listed by Ford, and consistent with 94S4P and 96S3P

It looks like the same connection plates are used for 3P and 4P, just with a different number of cell tabs attached. Note that there are four places where tabs are welded to these plates between cells groups, but in a 4P configuration there are four positive and four negative tabs to connect - you can different tab colour for the different polarities, and even a different weld style in the 4P example. In your 4P photo you can clearly see that each position has two stacked tabs; in the Munro video of the 3P module there isn't sufficient resolution to see that one position on each side will have only a single cell tab attached.

You don't have to guess and speculate at module sizes. There are images (still and video) posted online of both packs and all modules from them, and you can just count the plastic frame segments to see the different sizes.

• The larger modules of the standard pack in the Munro teardown video have 15 frames to hold 30 cells (10S3P)... not 16 frames to hold 24 cells (8S3P) plus 8 wasted spaces for a total of 32 times the cell thickness.
• The module which Munro takes out is the smaller module of the standard pack, and it has 12 frames to hold 24 cells (8S3P).
• Dave, you can count the frames in your 8S4P (16 frames for 32 cells) and 7S4P (14 frames for 28 cells) modules. Each frame holds two cells.

The modules sizes are based on observations, not assumptions.

The Mach E online order page is down because there are no more Mach E's available for this model year, but Green Car Reports snagged this image long ago:

It clearly shows the extra space on top at the rear of the pack for the extended battery. This is a nice side-by-side comparison, but there are many online images, mostly of the extended range battery.

BTW...back to the original premise... I think all the dual motor Mach-E's come standard with the ER pack which would mean the 4P modules which means you can have the higher current possible, which would make sense for dual motors.

I agree.

 

[D&VsEVJeep]

@brian_ Actually, after reading your well thought out and written message, I concede that I stand corrected. And actually, looking again at the Munro pic vs. my pic, I now do think the busbars are different between the 4P and 3P with the 3P being smaller and shifted slightly... Anyway, now your argument makes sense... Thanks for the patience and the write-up. I will still probably have to limit the current to the iM-225 with my cells in a 2P configuration due to size constraints... Just not much space in a Jeep keeping the 4WD and no batteries in the cabin...

 

[jehu]

Made a little video testing these cells

 

[UglyCarFan]

This is great information. For these specific batteries from Battery Hookup, what do you think is a REALISTIC estimation of number of cycles they would provide if the user is exercising restraint? I know that is difficult to say, but assume that they are not discharged below 20% of remaining capacity.

Thx!

 

[Clam77]

Hi Mitchy,
We will be testing our LG E71A cells soon to get some performance data. We also gave some cells to Orion for their BMS but I haven't received anything back from them yet. I can tell you that from our data logging in our Mustang Mach-E, full acceleration shows more than 650A... That is with the 4p extended range configuration so more than 162.5A per cell...

Hope this helps.

Hi, have you guys tested this out? I'm actually on a project team that was interested in some data on the LG batteries, more specifically,

• OCV Curves
• Resistance Curves
• Capacity

and anything else that might help. Thanks in advance!

 

[D&VsEVJeep]

Hi, have you guys tested this out? I'm actually on a project team that was interested in some data on the LG batteries, more specifically,

• OCV Curves
• Resistance Curves
• Capacity

and anything else that might help. Thanks in advance!

We had the intention of setting up a complete NI station with some EA power cyclers to run some real tests but a bigger OEM project consumed all the EA demo systems during the time we wanted to do the testing.

We do have some basic capacity curve data with a discharge current of 40A...if that helps. All of the capacities have checked in north of 140Ah for the pair of cells...

 

[Clam77]

We had the intention of setting up a complete NI station with some EA power cyclers to run some real tests but a bigger OEM project consumed all the EA demo systems during the time we wanted to do the testing.

We do have some basic capacity curve data with a discharge current of 40A...if that helps. All of the capacities have checked in north of 140Ah for the pair of cells...

That would absolutely help. Is it possible to share that capacity curve data at 40 Amps?