Prismatic battery module with scalable architecture

1. A battery system comprising:

a plurality of subunits each of which comprises a heatsink and a battery cell having a top end and first and second voltage terminals both of which extend out of the top end of the battery cell, said first and second terminals of each battery cell being symmetrically positioned with respect to a centerline of that battery cell, wherein all of the battery cells among the plurality of subunits are arranged so that their first voltage terminals are aligned along a first row and their second voltage terminals are aligned along a second row;

a plurality of identical busbar supports equal in number to the plurality of subunits, each busbar support among the plurality of busbar supports having two slots and being mounted on a corresponding different one of the subunits with each of the first and second terminals of the battery cell for that subunit extending up through a corresponding different one of the two slots; and

a plurality of bimetallic busbars, each one supported by a different corresponding subset of the busbar supports and electrically connected directly to either a first or second terminal of each of the battery cells of each of the modules on which those busbar supports are mounted, each one of the plurality of bimetallic busbars comprising:

a first segment comprising a first metal joined to a second segment comprising a second metal that is different from the first metal, such that the first segment and second segment partially overlap,

the first segment comprising, in a portion of the first segment that does not overlap with the second segment, a first u-shaped bend defining a first channel into which a first terminal of a first battery cell of the battery cells is positioned, the first terminal of the first battery cell comprising the first metal,

the second segment comprising, in a portion of the second segment that does not overlap with the first segment, a second u-shaped bend defining a second channel into which a first terminal of a second battery cell of the battery cells is positioned, the first terminal of the second battery cell comprising the second metal.

2. The battery system of claim 1 , wherein the battery cells are prismatic battery cells.

3. The battery system of claim 2 , wherein both the first row and the second rows are situated on the same side of the battery system.

4. The battery system of claim 3 , wherein each of the plurality of subunits are identical to one another except for the orientation of each of the battery cells of the subunits with respect to the battery cell's centerline.

5. The battery system of claim 3 , wherein each of the plurality of busbars electrically connects at least two adjacent terminals of the same row.

6. The battery system of claim 3 , further comprising a first pressure plate and a second pressure plate wherein the plurality of subunits is arranged as a stack of subunits and wherein the stack of subunits is located between the first pressure plate and the second pressure plate.

7. The battery system of claim 6 , wherein one or more compliant pads are located between the first pressure plate and the neighboring subunit.

8. The battery system of claim 6 , further comprising a band wherein the band encircles the first and second pressure plates and the plurality of subunits.

9. The battery system of claim 3 , wherein each of the plurality of subunits further comprises a second battery cell having a top end and first and second voltage terminals both of which extend out of the top end of the second battery cell, said first and second terminals of each second battery cell being symmetrically positioned with respect to a centerline of that battery cell wherein each of the second battery cells among the plurality of subunits are arranged so that their first voltage terminals are aligned along the first row and their second voltage terminals are aligned along the second row.

10. The battery system of claim 1 ,

wherein the first segment includes, in the portion of the first segment that does not overlap with the second segment, a third u-shaped bend defining a third channel into which a first terminal of a third battery cell of the plurality of battery cells is positioned, the first terminal of the third battery cell being made of the first metal, and

wherein the second segment includes, in the portion of the second segment that does not overlap with the first segment, a fourth u-shaped bend defining a fourth channel into which the first terminal of a fourth battery cell of the plurality of battery cells is positioned, the first terminal of the fourth battery cell being made of the second metal.