For many cruisers with simple electrical needs, a laptop computer can be the biggest power hog onboard. On our Creekmore 34, Eurisko, we need a laptop not only for my writing, but for our three homeschoolers. Until recently, we kept it charged through an inverter, which give us about four hours of computer time a day before our two 50-watt solar panels could no longer keep up and the house battery-bank voltage started dropping.
We finally realized the major culprit was the inverter. Specifically, we were wasting electricity by using it to change the boat’s 12-volt DC power to AC power for the computer’s 110-volt power cord, which then changed it back to DC power for the computer.
After weeks of research I found the web site laptoppartsnow.com, which sells 12-volt plugs for laptops. (Search by brand and model of your laptop.) Since we no longer waste energy converting DC to AC and then back to DC, I can use our laptop for 10 to 12 hours a day, and the batteries never notice it. When choosing a 12-volt charger for your computer, be sure to match the output (in volts and watts) of your 110-volt charger to that of the 12-volt charger you purchase. This ensures that the new charger will provide enough power for your laptop without damaging it.