An apparatus comprising: a substrate; an electrochromic device disposed on a surface of the substrate and having a perimeter comprising a first corner and a second corner, the first corner comprising a first vertex joining a first side and a second side, the second corner comprising a second vertex joining a third side and a fourth side; a first bus bar (805, 855, 1030, 1035, 1220, 1298) affixed to one of two conductive layers (810, 860, 1010, 1210, 1294) of the electrochromic device and proximate to the first corner, configured to operate at a first polarity and configured to deliver current and/or voltage for driving switching of the electrochromic device, the first bus bar (805, 855, 1030, 1035, 1220, 1298) including a first arm (806, 856, 1032, 1036, 1203) and a second arm (807, 857, 1031, 1202) having a configuration that substantially follows the shape of the first side, the first vertex, and the second side of the first corner, wherein the first arm (806, 856, 1032, 1036, 1203) of the first bus bar (805, 855, 1030, 1035, 1220, 1298) has a length in the range of 10 % to 65 % of the length of the first side of the perimeter of the electrochromic device, and wherein the second arm of the first bus bar has a length in the range of 10% to 65% of the length of the second side of the perimeter of the electrochromic device; and a second bus bar (815, 865, 1040, 1045, 1215, 1296) affixed to the other of the two conductive layers (820, 870, 1020, 1205, 1292) of the electrochromic device proximate the second corner, the second bus bar (815, 865, 1040, 1045, 1215, 1296) including a first arm (817, 866) and a second arm (816, 867, 1047) having a configuration that substantially follows the shape of the third side, the second vertex, and the fourth side of the second corner, the second bus bar (815, 865, 1040, 1045, 1215, 1296) configured to operate at a second polarity opposite the first polarity and configured to deliver current and/or voltage for driving switching of the electrochromic device, wherein the first arm (817, 866) of the second bus bar (815, 865, 1040, 1045, 1215, 1296) has a length in the range of 10 % to 65 % of the length of the third side of the perimeter of the electrochromic device, and wherein the second arm of the second bus bar has a length in the range of 10% to 65% of the length of the fourth side of the perimeter of the electrochromic device; wherein the first (805, 855, 1030, 1035, 1220, 1298) and second (815, 865, 1040, 1045, 1215, 1296) bus bars of opposite polarity are configured not to overlap along the perimeter. a substrate; an electrochromic device disposed on a surface of the substrate and having a perimeter comprising a first corner and a second corner, the first corner comprising a first vertex joining a first side and a second side, the second corner comprising a second vertex joining a third side and a fourth side; a first bus bar (805, 855, 1030, 1035, 1220, 1298) affixed to one of two conductive layers (810, 860, 1010, 1210, 1294) of the electrochromic device and proximate to the first corner, configured to operate at a first polarity and configured to deliver current and/or voltage for driving switching of the electrochromic device, the first bus bar (805, 855, 1030, 1035, 1220, 1298) including a first arm (806, 856, 1032, 1036, 1203) and a second arm (807, 857, 1031, 1202) having a configuration that substantially follows the shape of the first side, the first vertex, and the second side of the first corner, wherein the first arm (806, 856, 1032, 1036, 1203) of the first bus bar (805, 855, 1030, 1035, 1220, 1298) has a length in the range of 10 % to 65 % of the length of the first side of the perimeter of the electrochromic device, and wherein the second arm of the first bus bar has a length in the range of 10% to 65% of the length of the second side of the perimeter of the electrochromic device; and a second bus bar (815, 865, 1040, 1045, 1215, 1296) affixed to the other of the two conductive layers (820, 870, 1020, 1205, 1292) of the electrochromic device proximate the second corner, the second bus bar (815, 865, 1040, 1045, 1215, 1296) including a first arm (817, 866) and a second arm (816, 867, 1047) having a configuration that substantially follows the shape of the third side, the second vertex, and the fourth side of the second corner, the second bus bar (815, 865, 1040, 1045, 1215, 1296) configured to operate at a second polarity opposite the first polarity and configured to deliver current and/or voltage for driving switching of the electrochromic device, wherein the first arm (817, 866) of the second bus bar (815, 865, 1040, 1045, 1215, 1296) has a length in the range of 10 % to 65 % of the length of the third side of the perimeter of the electrochromic device, and wherein the second arm of the second bus bar has a length in the range of 10% to 65% of the length of the fourth side of the perimeter of the electrochromic device; wherein the first (805, 855, 1030, 1035, 1220, 1298) and second (815, 865, 1040, 1045, 1215, 1296) bus bars of opposite polarity are configured not to overlap along the perimeter.