Multi-cell battery module with integral cooling and assembly aids

1. A battery pack comprising:

a frame member that includes a floor, that includes walls formed perpendicular to the floor, and that includes an aperture defined by the walls,

wherein the frame member is formed from an electrically non-conductive plastic;

a first lithium ion cell that includes a first positive terminal and a first negative terminal, that includes a first electrically conductive housing, and that is disposed between the walls of the frame member,

wherein the first positive terminal is electrically connected to the first electrically conductive housing;

a second lithium ion cell that includes a second positive terminal and a second negative terminal, that includes a second electrically conductive housing, and that is disposed between the walls of the frame member,

wherein the second positive terminal is electrically connected to the second electrically conductive housing; and

an isolation plate moveable relative to the frame member in a first condition along at least two orthogonal axes within the frame member, the isolation plate directly contacting both the first and second electrically conductive housings and electrically isolating the first electrically conductive housing from the second electrically conductive housing,

wherein the isolation plate is formed from the electrically non-conductive plastic.

2. The battery pack of claim 1 further comprising a cooling system that is integrally formed in the frame member, the cooling system including:

coolant inlet and outlet ports that are formed in the frame member; and

a coolant channel that is formed through the frame member and that connects the coolant inlet and outlet ports.

3. The battery pack of claim 2 wherein the frame member includes:

an upper frame member that includes the floor and the walls, the floor defining at least a portion of a first portion of the coolant channel opposite the aperture; and

a lower frame member that includes a second portion of the coolant channel and that is joined to the upper frame member to seal the coolant channel.

4. The battery pack of claim 3 wherein the lower frame member is welded to the upper frame member.

5. The battery pack of claim 3 further comprising an adhesive that joins the lower frame member to the upper frame member.

6. The battery pack of claim 1 wherein the electrically non-conductive plastic is polypropylene.

7. The battery pack of claim 1 further comprising:

N other lithium ion cells that each include a positive terminal and a negative terminal, that each include an electrically conductive housing, and that are each disposed between the walls of the frame member,

wherein the positive terminal of each of the N other lithium ion cells is electrically connected to its electrically conductive housing, and

wherein N is an integer greater than zero; and

M other isolation plates that are each moveable relative to the frame in a first condition along at least two orthogonal axes within the frame member and that electrically isolate each of the electrically conductive housings and the first and second electrically conductive housings from each other,

wherein M is an integer that is greater than zero and less than or equal to N.

8. The battery pack of claim 7 further comprising:

a snap fitting element formed on an exterior surface of one of the walls of the frame member;

an end plate that interfaces the snap fitting element and that is held in abutment with the exterior surface when the end plate interfaces the snap fitting element;

a belt that encircles the frame member and the end plate; and

a compressing/restraining element that moves the belt to apply a compressive force on the frame member in a second condition such that the isolation plates are pressed into adjacent lithium ion cells.

9. The battery pack of claim 8 further comprising P other snap fitting elements formed on the exterior surface of the one of the walls of the frame member,

wherein P is an integer greater than zero, and

wherein the end plate further interfaces the P other snap fitting elements.

10. The battery pack of claim 8 wherein the snap fitting element is a cantilever type snap fitting element, and

wherein the end plate includes an aperture where the cantilever type snap fitting element interfaces the end plate.

11. The battery pack of claim 3 wherein:

the upper frame member is formed using injection molding; and

the lower frame member is formed using injection molding.

12. The battery pack of claim 3 further comprising:

a second upper frame member that includes a floor for a second plurality of cells, that includes walls formed perpendicular to the floor, that includes a second aperture defined by the walls, that includes a second coolant inlet port formed in the second upper frame member, that includes a second coolant outlet port formed in the second upper frame member, and that includes a first portion of a second coolant channel connecting the second coolant inlet port to the second coolant outlet port,

wherein the lower frame member further includes a second portion of the second coolant channel and is further joined to the second upper frame member to seal the second coolant channel.