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Some hints I have derived from public documents for the US-spec Solterra.

Battery pack is 96 cells and 72.8kWH. That's 758.3Wh/cell.

Battery pack is 96 cells and 355.2V. That's 3.7V/cell. The (likely) CATL cells are rated at 3.65-3.7V.

Rated capacity (according to the 2023 Subaru Solterra Specifications) is 201Ah. I think this wrong and is for the Panasonic pack. 205Ah at 355.2V is 72.8kWh. Now that's a bit better. 201Ah at 96 cells at 3.7V is 71.4kWh, which is the stated capacity of the FWD bZ4X pack.

I could find no public documents describing the 200-ish Ah (likely) CATL cells being used, but similar cells from them start at 50Ah and go up from there to 175AH.

They are constructed from prismatic cells, (likely) the same as the Panasonic cells.

Those cells are "8-1-1" type cells. That's 80% nickel, 10% cobalt, 10% magnesium.

Those cells have a nominal voltage of 3.7V.

The LFP cells from CATL have a nominal voltage of 3.2V.

The CATL NCM cells have a charging voltage of 4.2V and a maximum charging voltage of 4.25V.

For 96 cells if the DC fast charger supplied 400V, that would be 4.167V/cell, close to the rated charging voltage.

That explains the 355.2V-rated pack vs. the 400V DC fast charging.

Fast charge rate and max. charge rate are both 1.0C. That would generally indicate charging at a peak rate of no more than 82.7kW, definitely nowhere near the 150kW specified rate of the Panasonic cells and much closer to the 100kW specified rate of the CATL cells.

Maximum discharge for the CATL cells is specified as 2.0C, which is 145.6kW, which is close to what the two 80kW (rated) motor (likely) draw and the controllers might be limiting the draw to that 145.6kW, except maybe for brief periods.

Specified discharge (cell) temperature is rated for -20C to +60C or -4F to 140F.

Specified charging (cell) temperature is rated for 0C to +45C or 32F to 113F.

Most 8-1-1 cell charging curves show it accepting nearly no current at 0C and increasing from there.

All of this is consistent with what we have been hearing in the press releases.

Now, I would like to know why no one at Toyota or Subaru seemed to notice that the cell temp for DCFC had to be at least 32F?

I will do more research, but I think that when the 6.6kW AC charger is used, it might be able to warm the battery pack, whereas the DCFC circuitry might not be able to.

Start with the service manuals for the bZ4X on the site and peruse the electrical diagrams and other material if you want to figure this out. My two day subscription expired and I don't care to know the answer that much...

156 Posts
Yeah, manganese. Damn, if it was magnesium, that would explain the hot battery pack fires. o_O

I was quoting the 1.0C charge rate specified by CATL, though not necessarily for the exact cells being bought from CATL by Toyota.

A 355.2V NCM pack is fast charged by a 400V DC source. Anything less than 400V and charging is slower or non-existent. Anything greater exceeds the cell manufacturer's rated specifications upon which their warranty is based.

None of that means that CATL and Toyota aren't testing and qualifying appropriate charge settings and that they won't change (improve) over time. But that's a big hope.

Still interested in a Solterra.
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