For user convenience, the Newport Vessels Smart Battery Box is designed to measure the most accurate battery charge level of any user-supplied 12V Deep Cycle or Marine Battery when connected to a running motor. Despite the directions written on the battery box meter, the 12V battery hooked up inside the box needs to be under load by being connected to a running motor via the external box terminals for the meter to read the most accurate battery charge level of the battery.

To measure battery charge level while connected to a running motor: 

1. Press and hold the test button. The number of blue LEDs that are lit relative to the total number of LEDs will indicate the charge level of the battery

2. After you release the button, the last LED will blink for several seconds to confirm that the USB port is functioning correctly. If the USB port isn’t working properly, the last LED will not blink.

To use the USB Port, plug in the USB device into the port. Then press the test button to wake up the system. When the USB port is connected to a mobile device and charging it, the last LED will keep flashing for the duration of the connection.

So far the thousands of Newport Vessels Smart Battery Box users have found great use applications for the product even outside the boating and marine category.