Customer: I get AC power to the input terminals, but the LED lights are off and the system will not power up.

Troubleshoot: Did you use a DC voltmeter to check the voltage directly on the DC terminals?

Customer: Yes. The DC voltage is only 1.5 volts. Batteries are completely dead...

Troubleshoot: The battery bank voltage is too low. You must have at least 10 volts coming from the battery bank in order for the system to power up. If the batteries have fallen below 10 volts, you will have to charge the battery bank up with a different power source to at least 10 volts.