We're building our project Power Wagon to be a workhorse. Frou-frou bling need not apply. Our latest addition to this project is Terravolta's fascinating VoltaBox. This unit mounts in the cargo bed as simply as any other utility box, but it has the unique ability to generate 120-volt power using solar energy.Here's how it works: A BP Solar 80-watt solar panel is mounted on the lid of the VoltaBox. It generates 12-volt DC electrical power that is routed through a SunSaver 6 charge controller to a 100-ampere, deep-cycle absorbent glass mat (AGM) 12-volt battery. A 2,000-watt power inverter then draws the 12-volt power from the battery and converts it to 120-volt AC power. This power is sent to the built-in receptacles located on the outside and inside of the VoltaBox.
The company behind the VoltaBox, Terravolta, invested a significant amount of time into the design and testing of this product to ensure that the quality, safety, and reliability are top notch. They also offer a similar item for trailers and even a compact unit that can be used on ATVs. Our VoltaBox arrived almost completely assembled. In fact, it took longer to get it unpacked then it took to get it functional and installed in our Power Wagon. The team at Attitude Performance in Arlington Heights, Illinois, completed the quick installation for us while we took photos and recorded video.
Here's the lowdown on the install, features, and use of the VoltaBox.
The battery and all of the electronics are safely contained in a secure enclosure located on the inside of the VoltaBox. This photo shows how the components are laid out inside the enclosure. The 100-ampere Werker AGM deep-cycle battery resides in a plastic battery box (we have the lid off in this image), and the Vector 2,000-watt power inverter is mounted in the foreground. This modified sine wave inverter has dual cooling fans, overload and over-temperature shutdown, AC short-circuit shutdown, high and low voltage shutdown, and a low voltage alarm. Also included in the enclosure is an optional remote-operated alarm system, which utilizes a motion sensor. Here you can see the six-circuit...  Here you can see the six-circuit Buss ATC fuse panel. Below the panel, and out of sight in this image, is the 6.5-ampere SunSaver 6 charge controller. The SunSaver 6 is the world's leading small solar controller, and it's fully encapsulated in epoxy potting, 100-percent solid state, and it has marine-rated terminals. The folks at Terravolta designed the VoltaBox so that these items are easily accessible, yet protected by the enclosure. |  On the outside of the unit,...  On the outside of the unit, there's a weather-tight 120-volt receptacle and a 12-volt power point. |  Inside the unit, there are...  Inside the unit, there are receptacles integrated into the enclosure. Our test unit was specially built with four receptacles, but two are the norm. |
 Terravolta says the electrical...  Terravolta says the electrical system takes up only 20 percent of the internal toolbox space on the base unit, shown here. Speaking of the toolbox, it's an all-aluminum, low-profile Tradesman unit and it comes with dual latches and a handy removable plastic tray. We ordered ours in black, but chrome and custom colors are available. Ours also has the optional LED service light, which illuminates automatically when the lid of the VoltaBox is open. |  Since the VoltaBox system...  Since the VoltaBox system relies on solar energy to charge the battery, it has the usual limitations of any solar product-darkness, mostly cloudy days, or heavy shade. Hence, the VoltaBox comes standard with a 10-ampere Go Power! Smart Charger. This unit can be used to charge the VoltaBox battery should the situation warrant. It simply plugs into the 12-volt external power point to charge the battery from a wall outlet. This feature allows you to draw power from the VoltaBox in a shaded, remote area during the day, and then charge the unit at night in preparation for the next day's work. |  This is the BP Solar high-efficiency...  This is the BP Solar high-efficiency 80-watt solar panel. It uses 36 silicon nitride multicrystalline cells and mounts to the lid of the VoltaBox with six bolts. The 17-pound panel produces a maximum 17.6 volts and 4.5 amperes. According to the manufacturer, the panel has a temperature cycling range of minus 40 degrees Fahrenheit to 185 degrees Fahrenheit and it can withstand a 1-inch-diameter hailstone impact at 52 miles per hour. |
The Bottom Line
You probably have two questions. How does the VoltaBox work, and how much does it cost? We'll answer those questions in order.
To use the VoltaBox, you simply open the lid, engage the Buss circuit breaker, and push the switch on the remote Vector inverter control to engage the inverter. You can then close the lid and go to work. So far, we've used the VoltaBox to power a variety of electric tools, radios, battery chargers, and even a foot massager and guitar amplifier. The Vector modified sine wave inverter has powered everything we've plugged in so far, though it did create a background "buzz" when using the guitar amplifier. Terravolta says they can custom-build the VoltaBox with a true sine wave inverter if a customer wishes.
During the DeWalt compressor's motor break-in run, we operated the unit for 15 minutes at no load in a dark garage (in other words, no solar charging). At the end of the run, the compressor, which draws 2.6 amperes, caused no indicated drop in battery voltage. As a test of the VoltaBox's ability to provide sustained power with no solar charging, one night around 9:30 p.m., shortly after sunset, we plugged in a light fixture containing two 40-watt bulbs. We let it run until 5 a.m., just before sunrise. When we started the test, the VoltaBox voltmeter showed an indicated 13.5 volts. At the conclusion of the test, the system was still powering the lights and had an indicated 11.8 volts.
Even with full sunlight, it's possible to draw power from the battery faster than the solar panel can replace it. It's no different than using your rigs electric winch until the battery is depleted, for example. Naturally, this can be avoided by being aware of the electrical draw of whatever it is you're powering and/or monitoring the voltage of the VoltaBox battery via the built-in voltmeter.
The VoltaBox has a base price of $2,999. Our was loaded with almost every option available on the unit, including DeWalt air compressor ($304.20), electric cord guide and reel ($172.30), LED service light ($67.60), alarm system with remote ($101.40), and air hose reel ($177.45), which brought our as-tested price to $3,821.95.
We know what you're thinking. You could just buy a 2,000-watt inverter and power it off your rig for a lot less money. This is comparing apples to oranges, as they say, if you need a consistent source of 120-volt power. You would have to idle your rig's engine to keep the battery charged, or risk being stranded when your battery dies. Idling burns expensive fuel, which also creates emissions, and you'd be generating wear and tear on your rig. The VoltaBox, on the other hand, is self-sufficient, "green," and it offers the benefit of secure, weatherproof storage. Speaking of "green energy," Terravolta says the VoltaBox qualifies for a 30-percent federal tax credit for business.
We sacrificed some interior storage space by ordering our VoltaBox with the optional air compressor and reels, but we figure it's a good trade-off. We like the way the optional air hose reel and electric cord reel give us the ability to get air and power where we need it, easily, without messing around with tangled hoses and cords. We also like the fact that the VoltaBox has no electrical connections to the vehicle whatsoever, so it's very simple to install and it can be transferred to a different vehicle easily. So far, we're impressed with the performance of the VoltaBox. It just sits in the sun and silently makes power.