Power Inverters: The Comforts of Home

In days gone by, those home-style comforts were hard to find in a truckstop parking lot or a terminal yard. You made do with take-out coffee and maybe endless peanut-butter-and-jam sandwiches. Even the biggest sleeper on the road couldn’t really be a home.

No more. If you want to watch the Oilers smother the Flames while making dinner in a microwave and brewing a pot of coffee at the same time, you can. Thanks to industrial-grade power inverters, you can really live in that big truck-and easily save $50 or more every week in restaurant meals.

That’s the obvious benefit, but inverters are also a great way to limit idling a diesel engine. And they’re an effective tool for fleets struggling to attract and retain drivers. The cost of an inverter is much, much less than the hiring/testing/training routine, with real appeal to longhaul drivers.

Inverters, many of which have battery chargers built in, convert the DC electrical power coming from the truck’s batteries to ordinary 120-volt alternating current, just like in your home. Depending on the model you choose, you can run just about any appliance from a simple cell-phone charger to a combination of toasters and computers and refrigerators-you name it-at the same time.

Yes, many of these things can be had in DC form, but for price and selection you really need to think AC.

The smallest inverters, and thus the least capable, can be plugged into the truck’s cigarette lighter. They’re the kind you’ll find at truckstops for $75 or so, but they’ll do little more than run a laptop computer.

And if the wiring behind the dash is too light to carry the surge of power at start-up, they may have trouble doing even that. We’ve heard stories of people who watched their trucks burn to the ground because they tried to run a microwave oven off one of these little inverters. Horses for courses.

The bigger and better power inverters are hard-wired into the truck’s electrical system and incorporate a charger that provides the truck’s batteries with a fast, accurate and complete recharge when the inverter/charger is connected to 120-volt “shore power.”

The idea of shore power is the subject of much discussion these days, and there’s a U.S. lobby trying hard to get truckstops to provide AC plug-ins for their clientele. If some truckstops are resisting this, it’s not hard to see why.

Nonetheless, it’s starting to happen, and in the long run it has the potential to change the very nature of the truckstop.

Led by Western Star Trucks first and then Volvo Trucks, with Freightliner Trucks this month and other OEMs soon to follow, power inverters are now being offered as factory options in the $800 US range.

That’s the easiest way to choose the right one for your truck, but a retrofit is straightforward-at something like $1200 US and up plus installation for the kind worth having. Do-it-yourselfers can handle the installation with just basic mechanical skills, we’re told.

The first step is to decide what you want to power. A good-quality 1100-watt model, for example, can handle the big surge when appliances are first turned on, and simultaneously run a 900-watt microwave oven, a 100-watt TV/VCR, an 800-watt toaster, and a 900-watt coffee maker long enough to make breakfast-without fear of running batteries down. Look for an inverter/charger that’s rated on continuous output power, not a five-minute rating.

You want to know about its surge power too. A good 1100-watt unit might have a surge rating of 3000 watts, and be able to hold it for 10 minutes to get difficult loads started, for example. Not all inverters have safety code ratings such as “UL,” the main American testing lab, or “CSA,” the Canadian equivalent. You want one that does.

You also have to ask what happens when the inverter is not working. Lesser, consumer-grade inverters might actually soak up 30 watts or so, enough to drain your batteries in a weekend. Look for a “sleep” feature that drops the power consumption way down-to maybe one watt-if no AC is needed. Look as well for low-voltage cutout protection in which the AC draw is shut off if your batteries are sinking fast.