In rare circumstances, the INTELLIBOOST may not allow power to flow when needed. This could happen for a variety of reasons, including, but not limited to:
1) A defective battery (bad cell, short, sulfated, etc)
2) Poor clamp connection: Either the red positive or black negative cable are not solidly connected to the vehicle, possibly there is corrosion on the battery terminals or other factors causing this. Wiggle the cables to ensure this is not the case and a proper connection is established.
3) A short circuit or other issue causing abnormal draw from the vehicle.
If you are confident that you have eliminated any of the issues mentioned above and would like to force power from the jump starter to the vehicle, you can override the key INTELLIBOOST safety features by holding down the Override button for 8 seconds until you hear a beep and the light on the other side goes green.
Please note that using the override feature comes with risks, as power is flowing as soon as it is activated. It is important you are aware and willing to accept the risks before using this feature.