Cell holder with top and intermediate trays
A cell holder made up of a top tray, an intermediate tray and a frame. Cells are placed with minimal force in the frame to stand proud of it. The intermediate tray is placed over the projecting tops of the cells and serves to locate the cells. A busbar in the intermediate tray is connected to one set of terminals. A top tray is placed over the intermediate tray and snap-locked through the intermediate tray to the frame. The snap-lock distance is short. A busbar in the top tray is connected to the other set of terminals. The top tray shields the first busbar. Vents may be included to allow for the escape of hot cell gases in the event of failure.
1. A cell holder for one or more cells comprising:
a frame that hosts the one or more cells such that a portion of each cell projects beyond a top of the frame;
an intermediate tray on top of the frame and having one or more recesses each of which accommodates one of the projecting portions of the one or more cells, each recess partially covering a top surface of the cell the portion of which the recess accommodates; and
a top tray on top of the intermediate tray and directly fastened to the frame through the intermediate tray, thereby holding the intermediate tray in place.
2. The cell holder of claim 1 , comprising, in each recess, one or more protrusions on a wall of the recess to maintain the cell, the portion of which is accommodated by the recess, centered in a plane of the protrusions.
3. The cell holder of claim 1 , wherein the frame defines a cavity for each cell that it hosts.
4. The cell holder of claim 3 , wherein the one or more recesses in the intermediate tray are aligned with the one or more cavities in the frame.
5. The cell holder of claim 4 , wherein each recess has a smaller diameter than the corresponding cavity.
6. The cell holder of claim 3 , comprising, in each cavity, one or more protrusions on a wall of the cavity to maintain the cell that is in the cavity centered in a plane of the protrusions.
7. The cell holder of claim 3 , wherein each cavity has a ledge at a bottom section thereof that supports the cell in the cavity.
8. The cell holder of claim 7 , wherein each cavity is open to a bottom surface of the frame.
9. The cell holder of claim 8 , comprising a cooled plate that is glued to bottom surfaces of the one or more cells when the one or more cells are in the cell holder.
10. The cell holder of claim 1 , wherein:
the top tray comprises studs each with a snap lock at its extremity;
the intermediate tray defines holes through each of which one of the studs passes; and
the frame defines further holes each with a retaining surface to which one of the snap locks engage.
11. The cell holder of claim 10 , wherein each retaining surface is a step in a wall of one of the further holes.
12. The cell holder of claim 10 , wherein a ratio of snap locks to cells is between 1:1 and 10:1.
13. The cell holder of claim 10 , wherein the snap locks are irreversible.
14. The cell holder of claim 10 , wherein the snap locks are reversible.
15. The cell holder of claim 1 , wherein the frame, the intermediate tray and the top tray are made of polycarbonate/acrylonitrile-butadiene-styrene.
16. The cell holder of claim 1 , comprising a negative busbar in the top tray and a positive busbar in the intermediate tray.
17. The cell holder of claim 1 , comprising locating features in the frame and the intermediate tray that engage with each other.
18. The cell holder of claim 1 , wherein the intermediate tray, the top tray, or both the intermediate and top trays define vents between the top surfaces of the one or more cells and an exterior of the cell holder.
19. A method for assembling a cell holder for one or more cells comprising:
placing the one or more cells in a frame that hosts the one or more cells such that a portion of each cell projects beyond a top of the frame;
placing an intermediate tray on top of the frame, the intermediate tray having one or more recesses each of which accommodates one of the portions of the one or more cells that project beyond the top of the frame, each recess partially covering a top surface of the cell the portion of which the recess accommodates;
connecting a busbar in the intermediate tray to a terminal on each of the one or more cells;
placing a top tray on top of the intermediate tray;
directly fastening the top tray to the frame through the intermediate tray, thereby holding the intermediate tray in place; and
connecting another busbar in the top tray to a second terminal on each of the one or more cells.
20. The method of claim 19 comprising gluing bottom surfaces of the one or more cells to a cooled plate.