[TeZla]

I saw this on SuperfastMatt's instagram page, a short version of the Model3 battery, From what little i've been able to research so far, its a NCA (Nickel Cobalt Aluminium) battery in the latest? models. looks like its from the new SR+ model.
Does anyone have any more info or knowledge on these? It seems to be around a 50kWh battery.

It looks like it would be a lot easier to repackage into a useful conversion, My thoughts is that two modules could be laid flat side by side, with the other two on their long sides running down the middle. the footprint of the whole pack would be very similar in size and shape to that of a straight 6 engine and transmission, so it'll package well in the engine bay and transmission tunnel, keeping the overall weight low and centered.
I've never really liked the idea of splitting the battery into separate packs or mounting them up high, such as in the boot or as a large bulky box that fills the entire engine bay.

 

[remy_martian]

I would have loved to be in that meeting at Tesla where the vehicle dynamics engineer got pummeled into submission.

 

[brian_]

I saw this on SuperfastMatt's instagram page, a short version of the Model3 battery, From what little i've been able to research so far, its a NCA (Nickel Cobalt Aluminium) battery in the latest? models. looks like its from the new SR+ model.
Does anyone have any more info or knowledge on these? It seems to be around a 50kWh battery.

I assume that it is the new (starting November 2021) Standard Range, replacing the previous Standard Range and Standard Range Plus. The Specifications table in the Wikipedia page for the Model 3 shows only one less-than-long-range battery, with a capacity "62.3 kWh (224 MJ) of which 60 kWh (220 MJ) is usable" from a press article - I've seen at least one article online giving those specs.

If this is the battery which is new this month, I don't know how Matt got a photo of one torn open already... and I didn't ask.

For those not familiar with the earlier lower-capacity Model 3 modules: they were the same overall dimensions as the long-range modules, but with rows of cells missing down the middle of each module so there were fewer cells per group, less energy capacity, less weight, but the same pack and module voltages.

One interesting detail: the large modules are different lengths, with 23S modules on each side and longer 25S modules in the middle, allowing the pack to have clipped off corners for wheel well clearance, but there's no need for that in these shorter modules so they're all the same length (and would be 24S each).

 

[brian_]

I would have loved to be in that meeting at Tesla where the vehicle dynamics engineer got pummeled into submission.

The new modules are at the back of the pack, which makes sense electrically to connect to the ancillary components in the penthouse under the rear seat. That moves the centre of mass rearward, but only by reducing the mass in the front (fewer of the same cells). That means that the vehicle's static rear axle load would be reduced only slightly, while the front axle load would be reduced by a larger amount (but still a small fraction of the vehicle mass). In a rear-wheel-drive vehicle (which is the only variant using this battery) as long as suspension parameters (spring rates, damper settings) and tire sizes (and pressures) are adjusted to suit that's not a bad thing for vehicle dynamics.

There have been Model 3 variants with staggered tire sizes (wider in the rear), but the 2021 owner's manual currently offered by Tesla.com for Canada shows all tires the same section width (235 mm). Perhaps stagger would be appropriate for the RWD with smaller battery, but I suspect that they wouldn't bother without more motor power.

Of course one can go too far with this. The original Model 3 apparently ran 48:52 (front:rear) or maybe 47:53 (depending on information source) weight distribution. With rear passengers and cargo, it could be more rear-heavy than really wanted, although at least it has a modern suspension (not the semi-trailing arms of the old 1960's rear-engine death traps). It's not going to approach the roughly 40:60 of those evil-handling mid-engine exotics or the 38:62 of the terrible Lotus Elise.

In an ideal world the lower front axle load would lead to less steering boost and the addition of some steering feel, but I'm sure it's as numb as ever.

 

[remy_martian]

Good point. Less steering boost -> better "gas mileage", so maybe that is what they're up to.

Do drive-cycle tests include steering inputs, or are they just speed variations?

In the Lotus, the driver is ~10% of the vehicle weight, lol.

 

[brian_]

In the Lotus, the driver is ~10% of the vehicle weight, lol.

Yes, the Elise driver's mass is more significant to the vehicle than in the Model 3, but the Elise driver sits at nearly the centre of mass, so that's essentially irrelevant to handling. In a Model 3, the driver is nearly at the middle of the wheelbase, and rear passengers and cargo are rearward enough that adding them shifts the centre of mass rearward. Net effect - I doubt that anyone at Tesla is upset by this battery's mass distribution.

 

[joekitch]

Bumping an old post but...
Was it ever found a range of serial numbers which would have these shorty modules inside? Or a specific year of car? Some way to externally identify the short modules were inside

Also, how much does one of these packs weigh?

Also if there's a usable BMS solution out there yet

 

[Sir Horatio Nelson]

Here you go.

Battery pack part numbers: 1104428-00-R, 1137378-01-, 1522118-*-, 1104428-00-P, 1104426-00-, 1104428-0L-, 1104426-00-P.

I believe the pack, including penthouse, weighs north of 700lbs, but less than the larger pack which, I think is somewhere around the 1000lbs mark.

For my projects, I cut the battery case down and seal it back up close to the modules. My guess is it shaves off ~120lbs.

I strongly recommend buying an intact M3 battery which includes it's entire BMS and utilizing Ingenext's battery and motor controller. HTH. No need to reinvent; just might need to reshuffle.

 

[robertwa]

Here you go.

Battery pack part numbers: 1104428-00-R, 1137378-01-, 1522118-*-, 1104428-00-P, 1104426-00-, 1104428-0L-, 1104426-00-P.

This is helpful thanks! Since many ebay listings do not include the PN upfront, do you know if there was a particular build spec or period when these packs were produced?

Thinking about it more, when I ordered my wife's Model 3, back with all the auto delays, they contacted us to ask if we were willing to take a slightly different spec and I think* it was lower range with them citing it as a Euro or Asian battery spec. Maybe I have the short modules in my wifes DD. Hmmm, maybe I should upgrade hers and take the shorty's for my conversion..... wait, it's a Tesla, I'm sure the computer would say no.....

 

[Sir Horatio Nelson]

Hi robertwa,

To keep it simple, I'd say just put eyes on the pack's serial number // PN sticker on the penthouse. Example attached. Short of pulling the battery, my Tesla tech that helps me on my builds is unaware of an easy-ish way to validate. Others may have an idea.