A simple, safe and affordable way to connect 2 batteries simultaneously for easy battery maintenance. The BC2AY assembly contains insulated 24" battery clip cord set with 15 amp fused qwik-connect plug (BC-AA) paired with 210AY Y-Connector with SmarTECHnology-. Designed specifically for our Aviation models, the BC2AY can also be used with our other models except for the 28252, 12151, and OBD 12, 24, 36, 48. 2 Never connect two or more batteries together before fully charging each and checking its condition. Failure to fully charge each battery and check its condition can result in a serious safety hazard.