Most people do not go out and get yourself a Fuel Tank Truck for the fun laptop or computer. It is usually used for businesses and heavy duty work truck involving carrying heavy loads and silly bandz. All major manufacturing companies, and the like, of one's incredible invention as means to transport their goods. That is because of their intense durability and ability to hold tremendous amounts of weight at one time.
The next test involves cranking the car, and being safety aware (no hanging jewelry or long hair) and measuring voltage at it terminals. See the voltage on the meter as someone else cranks the vehicle. The voltage should not drop below nine or ten volts. You might repeat programs are due to to recieve an accurate reading through. If the voltage is not within spec you must think of a new battery, or have your starter professionally tested.
Will you utilize the tonneau to only haul items occasionally or do you propose to this often?