Flexible circuit board for a conformal wearable battery
A flexible printed circuit board assembly (PCBA) for a conformal wearable battery (CBB) includes attachment sections for a plurality of battery cells that are arranged in a grid-like pattern on a same side of the flexible PCBA. The flexible PCBA is configured to fold along a bend axis so that the flexible PCBA is folded approximately in half. To reduce mechanical stresses placed on the flexible PCBA when folding the flexible PCBA along the bend axis, the flexible PCBA includes a plurality of cut-outs dispersed along the bend axis and parallel to adjacent battery cells. The CWB is configured to flex during use. The flexible PCBA includes a plurality of cut-outs disposed perpendicular to the bend axis, between adjacent rows of battery cells, and on the bend axis to relieve mechanical stresses applied to a bent portion of the flexible PCBA when the CWB is flexed during use.
1. A conformal wearable battery comprising:
a plurality of battery cells; and
a flexible printed circuit board assembly (PCBA) comprising:
a plurality of physical connection sections disposed in a grid like pattern, wherein each battery cell of the plurality of battery cells is physically affixed to the flexible PCBA at a corresponding physical connection section of the plurality of physical connection sections;
a bend axis disposed between two parallel physical connection sections, wherein the bend axis facilitates folding of the flexible PCBA in half;
a plurality of first cut-outs disposed along the bend axis, wherein a longer edge of each first cut-out of the plurality of first cut-outs is disposed parallel to the bend axis;
a plurality of second cut-outs disposed across the bend axis, wherein a longer edge of each second cut-out of the plurality of second cut-outs is disposed perpendicular to the bend axis; and
a plurality of third cut-outs disposed in pairs along a flex line perpendicular to the bend axis, wherein each pair of the third cut-outs facilitate an electrical connection, to the flexible PCBA, from a battery cell of the plurality of battery cells.
2. The conformal wearable battery of claim 1 , wherein the flexible PCBA comprises a first plurality of electrical connections each connecting a cathode of a corresponding battery cell of the plurality of battery cells and second plurality of electrical connections each connecting an anode of the corresponding battery cell of the plurality of battery cells to electrical conductors of the flexible printed circuit board assembly.
3. The conformal wearable battery of claim 1 , wherein the bend axis comprises a center of the grid like pattern of the physical connection sections.
4. The conformal wearable battery of claim 1 , wherein each first cut-out of the plurality of first cut-outs is substantially rectangular-shaped.
5. The conformal wearable battery of claim 1 , wherein each corner of each first cut-out of the plurality of first cut-outs is rounded.
6. The conformal wearable battery of claim 1 , wherein each second cut-out of the plurality of second cut-outs comprises a first semi-circular section, a second semi-circular section and a rectangular section.
7. The conformal wearable battery of claim 6 , wherein the rectangular section is disposed between the first semi-circular section and the second semi-circular section.
8. The conformal wearable battery of claim 6 , wherein the rectangular section is disposed laterally across the bend axis, wherein a mid-point of the rectangular section is located near the bend axis.
9. The conformal wearable battery of claim 1 , wherein each of the plurality of battery cells is physically attached to a first side of the flexible PCBA.
10. The conformal wearable battery of claim 1 , wherein the plurality of battery cells are disposed on an outside surface of the flexible PCBA, when the flexible PCBA is in a folded configuration.
11. The conformal wearable battery of claim 1 , further comprising a sealed flexible housing wherein the flexible PCBA is disposed within an interior cavity of the sealed flexible housing and wherein the flexible PCBA is in a folded configuration.
12. A system comprising:
a plurality of battery cell modules;
a flexible printed circuit board assembly (PCBA) comprising:
a plurality of battery cell connection sections disposed in a grid-like pattern along a first surface of the flexible PCBA;
a bend axis configured to divide the flexible PCBA in half when the flexible PCBA is in a folded configuration;
a plurality of first cut-outs disposed along the bend axis, wherein each of the plurality of first cut-outs reduce a bending force placed on the flexible PCBA when a flexing force is applied to the flexible PCBA; and
a plurality of second cut-outs disposed in pairs along a first flex line perpendicular to the bend axis and between adjacent battery cell modules, wherein each pair of the second cut-outs facilitate an electrical connection, to the flexible PCBA, from a battery cell module of the plurality of battery cell modules.
13. The system of claim 12 , wherein the plurality of first cut-outs comprises:
a plurality of third cut-outs having a first shape; and
a fourth plurality of cut-outs having a second shape.
14. The system of claim 13 , wherein the first shape comprises a substantially rectangular shape having rounded corners.
15. The system of claim 13 , wherein the second shape comprises at least one semi-circular section and a rectangular section.
16. The system of claim 13 , wherein the second shape comprises a rectangular section disposed across the bend axis and a first semi-circular section disposed at an end of the rectangular section on a first side of the bend axis and a second semi-circular section disposed at an opposite end of the rectangular section and on an opposite side of the bend axis.
17. The system of claim 12 , wherein a first cut-out of the first plurality of cut-outs are is located near an approximate mid-point of a battery cell module and between the first flex line and a second flex line.
18. The system of claim 12 , wherein a second cut-out of the first plurality of cut-outs is disposed on the first flex line.
19. A flexible printed circuit board assembly (PCBA) comprising:
a plurality of battery modules physically affixed to the flexible PCBA, wherein the plurality of battery modules are arranged in a grid-like pattern;
a bend axis is near an approximate mid-point of the flexible PCBA, wherein bending the flexible PCBA along the bend axis results in a folded configuration of the flexible PCBA;
a plurality of first cut-outs disposed in pairs along a flex line perpendicular to the bend axis, wherein each pair of the first cut-outs facilitate an electrical connection, to the flexible PCBA, from a battery module of the plurality of battery modules; and
a plurality of second cut-outs disposed along the bend axis, wherein the plurality of second cut-outs reduce a force exerted on the flexible PCBA along the bend axis when the flexible PCBA is flexed.
20. The flexible PCBA of claim 19 , wherein the plurality of second cut-outs disposed along the bend axis comprises a plurality of third cut-outs having a first shape and a plurality of fourth cut-outs having a second shape and wherein the plurality of third cut-outs are disposed parallel to a flexible portion of the flexible PCBA between adjacent rows of the grid-like pattern that and wherein a longer edge of the third cut-out of the plurality of third cutouts is perpendicular to the bend axis and the plurality of fourth cut-outs are disposed between adjacent battery modules arranged in columns of the grid-like pattern, wherein the columns are on opposite sides of the bend axis, and wherein a longer edge of the fourth cut-out is disposed parallel to the bend axis.