Flexible battery matrix for a conformal wearable battery
A matrix of battery cell modules includes a flexible printed circuit board assembly (PCBA) for a conformal wearable battery (CWB) with a plurality of attachment sections for each of a plurality of battery cells that are arranged in a grid-like pattern on a same side of the flexible PCBA. Each battery cell may be joined with a flexible PCB via a welding process. The flexible PCBA is configured to fold along a bend axis so that the flexible PCBA is folded approximately in half. When affixed to the flexible PCBA, the plurality of battery cell modules and a circuitry module form a grid of physical components. When folded, the flexible PCBA forms a three-dimensional grid of physical components comprising at least the battery cell modules.
1. A system comprising:
a first plurality of battery cells, wherein a first battery cell of the first plurality of battery cells includes a first pair of electrically conductive elements;
a second plurality of battery cells, wherein a second battery cell of the second plurality of battery cells includes a second pair of electrically conductive elements; and
a flexible printed circuit board (PCB) comprising:
a plurality of battery cell connection sections disposed in a grid-like pattern along a first surface of the flexible PCB;
a plurality of cutouts disposed adjacent and parallel to an edge of the plurality of battery cell connection sections, wherein the plurality of cutouts is arranged as multiple pairs of cutouts arranged adjacent a majority of the plurality of battery cell connection sections; and
a plurality of electrical connection pads disposed on a second surface of the flexible PCB opposite the first surface, wherein a majority of the plurality of electrical connection pads are arranged adjacent the plurality of cutouts, wherein the plurality of electrical connection pads comprise an electrically conductive surface coating;
wherein an electrically conductive element of the first pair of electrically conductive elements wraps around an edge of the flexible PCB and extends along the second surface of the flexible PCB, wherein the electrically conductive element of the first pair of electrically conductive elements connects to a corresponding electrical connection pad of the plurality of electrical connection pads forming a first electrical connection; and
wherein an electrically conductive element of the second pair of electrically conductive elements extends through a cutout of the plurality of cutouts, wherein each electrically conductive element of the second pair of electrically conductive elements connects to a corresponding electrical connection pad of the plurality electrical connection pads forming a second electrical connection.
2. The system of claim 1 , wherein the first electrical connection between the electrically conductive element of the first pair of electrically conductive elements and the corresponding electrical connection pad of the plurality of electrical connection pads are joined with a weld.
3. The system of claim 2 , wherein the weld is formed using a laser welding process.
4. The system of claim 3 , wherein the weld is formed using an ultrasonic welding process.
5. The system of claim 1 , wherein a connection pad of the plurality of electrical connection pads has a circular shape with a diameter that is within a range of 1.8 times and 3 times a width of an electrically conductive element of the first pair of electrically conductive elements.
6. The system of claim 1 , wherein the first plurality of battery cells and the second plurality of battery cells comprise pouch cell packaged polymer lithium-ion.
7. The system of claim 1 , wherein the electrically conductive surface coating comprises an electroless nickel immersion gold (ENIG) surface coating.
8. The system of claim 1 , wherein the electrically conductive surface coating comprises a lead-free immersion silver surface coating.
9. The system of claim 1 , wherein a first height of the first electrical connection is within a range of 1.2 to 3 times a thickness of a first electrically conductive element of the first pair of electrically conductive elements and a second height of the second electrical connection is within a range of 1.2 to 3 times a thickness of a second electrically conductive element of the second pair of electrically conductive elements.
10. A conformal wearable battery comprising:
a first plurality of battery cells; wherein a first battery cell of the first plurality of battery cells includes a first pair of electrically conductive elements;
a second plurality of battery cells, wherein a second battery cell of the second plurality of battery cells includes a second pair of electrically conductive elements, wherein the first plurality of battery cells and the second plurality of battery cells comprise pouch cell packaged polymer lithium-ion; and
a flexible printed circuit board (PCB) comprising:
a plurality of battery cell connection sections disposed in a grid-like pattern along a first surface of the flexible PCB;
a plurality of cutouts disposed adjacent and parallel to an edge of the plurality of battery cell connection sections, wherein the plurality of cutouts is arranged as multiple pairs of cutouts arranged adjacent a majority of the plurality of battery cell connection sections; and
a plurality of electrical connection pads disposed on a second surface of the flexible PCB opposite the first surface, wherein a majority of the plurality of electrical connection pads are arranged adjacent the plurality of cutouts, wherein the plurality of electrical connection pads comprise an electrically conductive surface coating;
wherein an electrically conductive element of the first pair of electrically conductive elements wraps around an edge of the flexible PCB and extends along the second surface of the flexible PCB, wherein the electrically conductive element of the first pair of electrically conductive elements connects to a corresponding electrical connection pad of the plurality of electrical connection pads forming a first electrical connection;
wherein an electrically conductive element of the second pair of electrically conductive elements extends through a cutout of the plurality of cutouts, wherein each electrically conductive element of the second pair of electrically conductive elements connects to a corresponding electrical connection pad of the plurality electrical connection pads forming a second electrical connection; and
wherein a first height of the first electrical connection is within a range of 1.2 to 3 times a thickness of a first electrically conductive element of the first pair of electrically conductive elements and a second height of the second electrical connection is within a range of 1.2 to 3 times a thickness of a second electrically conductive element of the second pair of electrically conductive elements.
11. The conformal wearable battery of claim 10 , wherein the first electrical connection between the electrically conductive element of the first pair of electrically conductive elements and the corresponding electrical connection pad of the plurality of electrical connection pads are joined with a weld.
12. The conformal wearable battery of claim 11 , wherein the weld is formed using a laser welding process.
13. The conformal wearable battery of claim 11 , wherein the weld is formed using an ultrasonic welding process.
14. The conformal wearable battery of claim 10 , wherein a connection pad of the plurality of electrical connection pads has a circular shape with a diameter that is within a range of 1.8 times and 3 times a width of an electrically conductive element of the pair of electrically conductive elements.
15. A flexible printed circuit board (PCB) assembly comprising:
a first plurality of battery cells; wherein a first battery cell of the first plurality of battery cells includes a first pair of electrically conductive elements;
a second plurality of battery cells, wherein a second battery cell of the second plurality of battery cells includes a second pair of electrically conductive elements; and
a flexible printed circuit board comprising:
a plurality of battery cell connection sections disposed in a grid-like pattern along a first surface of the flexible PCB;
a plurality of cutouts disposed adjacent and parallel to an edge of the plurality of battery cell connection sections, wherein the plurality of cutouts is arranged as multiple pairs of cutouts arranged adjacent a majority of the plurality of battery cell connection sections; and
a plurality of electrical connection pads disposed on a second surface of the flexible PCB opposite the first surface, wherein a majority of the plurality of electrical connection pads are arranged adjacent the plurality of cutouts, wherein the plurality of electrical connection pads comprise an electrically conductive surface coating comprising an electroless nickel immersion gold (ENIG) surface coating;
wherein an electrically conductive element of the first pair of electrically conductive elements wraps around an edge of the flexible PCB and extends along the second surface of the flexible PCB, wherein the electrically conductive element of the first pair of electrically conductive elements connects, by a weld, to a corresponding electrical connection pad of the plurality of electrical connection pads forming a first electrical connection; and
wherein an electrically conductive element of the second pair of electrically conductive elements extends through a cutout of the plurality of cutouts, wherein each electrically conductive element of the second pair of electrically conductive elements connects to a corresponding electrical connection pad of the plurality electrical connection pads forming a second electrical connection.
16. The flexible printed circuit board (PCB) assembly of claim 15 , wherein the first plurality of battery cells and the second plurality of battery cells comprise pouch cell packaged polymer lithium-ion.
17. The flexible printed circuit board (PCB) assembly of claim 15 , wherein the weld is formed using a laser welding process.
18. The flexible printed circuit board (PCB) assembly of claim 15 , wherein the weld is formed using an ultrasonic welding process.
19. The flexible printed circuit board (PCB) assembly of claim 15 , wherein a connection pad of the plurality of electrical connection pads has a circular shape with a diameter that is within a range of 1.8 times and 3 times a width of an electrically conductive element of the pair of electrically conductive elements.
20. The flexible printed circuit board (PCB) assembly of claim 15 , wherein a first height of the first electrical connection is within a range of 1.2 to 3 times a thickness of a first electrically conductive element of the first pair of electrically conductive elements and a second height of the second electrical connection is within a range of 1.2 to 3 times a thickness of a second electrically conductive element of the second pair of electrically conductive elements.