Part Number: 0900-58, 0900-59

Q: When I connect my laptop or notebook computer to the inverter, the inverter light changes back and forth from green to red and my laptop’s screen alternates between bright and dim.

A: A few newer laptop computers have charge circuits which pulse the laptop’s internal battery to charge it. These pulses draw far more power from the inverter than it’s peak rating allows. The inverter has a built-in safety circuit designed to protect the inverter and your vehicle from high power overloads that could blow fuses and cause damage to wiring. If the lights on your inverter are alternating green and red it is because the laptop has a battery charging circuit demanding power in pulses that exceeds the peak rating of the inverter.

If the laptops screen alternates between bright and dim, it is because the inverter’s protection circuit is temporarily shutting off power. The laptop senses this and goes into power-saving mode which automatically dims the screen. When the inverter’s protection circuit senses that the overload has past, it then restores power. When the laptop senses the power coming back on, it automatically brightens the screen.

If your computer contains this pulsing-type battery charge circuit, you can still power the computer from the inverter by removing the battery from the computer. The computer can then be operated as normal, and the battery can be charged when a 120 volt wall outlet is available.