In today’s competitive trucking market, fleet managers are challenged to reduce fuel costs, minimize maintenance requirements and improve truck driver retention. There is simply so much to keep track of, what is a fleet manager to do? Furthermore, how can technology investments impact how much trucking companies improve efficiency?
One way is in the cab. As trucking companies invest more in truck driver comfort, the cab is the new vanguard on multiple fronts, from fuel savings to truck driver retention. Simply put, cabs are now so technologically advanced they are in and of themselves an important asset. Now the question is this: What do fleet managers need from their cab to meet company goals?
The Sleeper Cab Wakes Up
For years, fleet managers have specified sleeper cabs with diesel-powered APUs to reduce tractor idling and maintenance costs. Just like truck OEMs, APU manufacturers are also electrifying their power units. Transitioning from diesel-powered APUs to electric APUs (EPUs) cuts fuel costs even further, while simultaneously reducing levels of both noise and pollution. The main challenge for EPUs is runtime, since there is typically limited space onboard to accommodate a second battery bank.
This is where lithium-ion technology comes in. Lithium-ion batteries and solar panels are game changers because they eliminate this concern altogether. These breakthrough technologies ease operational considerations in areas subject to engine-based APU restrictions and can significantly reduce or eliminate tractor auto-starts when drivers break for 34-hour restarts. Save fuel and the environment.
When they stop for the day, over-the-road truckers can either idle their engine to power hotel loads in the sleeper cab or shut down completely and use either battery power or an onboard generator to run electrical devices like, air conditioners, heaters, microwaves and televisions.
Battery-powered APUs have historically been at a disadvantage, particularly when operating in hot southern regions during the summer when the air conditioner runs continuously. The result is a state of near-constant truck auto-starts and increased fuel consumption, along with greater engine wear. What’s more, it can take many hours to fully recharge the batteries for an all-electric APU, whether that is accomplished by running the truck engine or plugging directly into an AC outlet.
The Lithium-Ion Revolution
Lithium-ion changes everything by taking battery performance to an entirely new level. Just consider how much this technology has changed the auto industry. Corporate titans like Elon Musk have even created new semi-trucks based on lithium-ion battery technology.
They are preferred because of one main reason. Lithium-ion batteries outperform traditional AGM/lead acid cells in several significant ways. And many providers now offer lithium-ion batteries in various capacities for all types of trucking applications, providing a wide range of benefits including:
- Greater run time: Up to twice the run time of comparable AGM/lead acid cells.
- Longer service life: Up to six times as long as comparable batteries.
- Steady power drain – 12.1 volts, all the time.
- Lighter weight: Lithium-ion batteries typically weigh half as much as traditional lead acid or AGM batteries.
- More compact footprint: Lithium-ion batteries are up to one half the size of deep-cycle AGM batteries of comparable power.
Perhaps the greatest benefit of lithium-ion batteries is the ability to access and use the battery’s entire charge. It should be noted that the maximum discharge for a traditional lead acid battery is to a level of about 50 percent of its total capacity. Exceeding this level may void the battery’s warranty and reduce its service life. This is a major limitation in these types of batteries.
By comparison, a lithium-ion battery can be run all the way to a 0 percent state of charge, although typically users will not run it lower than 10 percent in order to ensure a power reserve exists until it can be recharged. The ability to access far more of the battery’s actual capacity results in a substantially greater run time, enabling lithium-ion batteries to power loads for far longer than traditional cells.
In practical use, swapping 400-amp hours of AGM/lead acid for 400-amp hours of lithium-ion would double your available run time for all hotel loads, including air conditioners.
The Advantages Mount
Another significant advantage of lithium-ion batteries is their longer life cycle. Where a traditional battery might deliver anywhere from 500 to 900 charging cycles and may require replacement every year, a lithium-ion battery can provide a service life from 3,000 to 5,000 charging cycles.
Despite their higher initial cost, lithium-ion batteries provide superior ROI by offering up to six times more charging cycles than a traditional battery, and thereby requiring less frequent replacement. Motor carriers save more money in the long run.
Voltage stability is still another area where lithium-ion batteries set a new standard in power management, by delivering a consistent 12.1 volts all the way through the entire cycle of the battery. By comparison, an AGM/lead acid battery can only deliver a full 12.1 volts through the top 20 to 30 percent of its charge; below that point voltage begins to drop steadily.
Knowing that equipment in the truck has been designed to work on 12 volts, once that point has been reached the efficiency of DC powered appliances and the HVAC system are compromised. For this reason, electric APUs (EPUs) will run more efficiently and deliver longer runtimes and a longer life cycle when powered by lithium-ion batteries.
Another benefit to their voltage stability is that lithium-ion batteries provide superior performance with inverter/chargers. Fleets can find on the market inverter/chargers that are fully compatible with corresponding lithium-ion battery combos.
How Solar Fits into the Equation
Where lithium-ion batteries represent a quantum leap forward in managing hotel loads in HD Class 8 truck sleeper cabs, they work even better when combined with solar panels that can maintain a constant trickle charge and offset parasitic loads. Imagine the sustainability bona fides, as well.
With five to six hours of daily sunlight, a pair of 100-watt solar panels can generate from 60 to 72-amp hours’ worth of power per day. That represents an extra hour or two of air-conditioning or heating, along with power left over to microwave some popcorn and enjoy a movie on DVD. Solar reduces the depth of discharge on batteries, resulting in extended battery life.
The real benefit to solar comes when drivers have stopped under a 34-hour restart break. It should be noted that many truck drivers spend this time in the sleeper cab where, in hot climates, they’re running the air conditioner continuously. The result is near-constant auto-starts on the engine. A lithium-ion battery pack supported by a solar panel system can help eliminate those auto-starts, subsequently reducing fuel consumption, reducing carbon emissions, and reducing engine wear.
While solar may not function as the primary battery charger, it will definitely extend battery charge life and, in turn, the service life of the battery itself. Fleet managers may find the ROI on a solar system to be as little as six months. There are a variety of solar panels in rigid and flexible formats and in different sizes on the market.
Adopting New Innovations
Lithium-ion battery systems supported by solar panels are a game changer in the commercial trucking industry. If the truck isn’t already equipped with one, add an inverter charger configured to work with lithium-Ion batteries Install a dedicated lithium-Ion battery bank to handle all hotel loads, including EPUs
Install a solar panel system to provide constant trickle charging Electric APU units powered by lithium-ion/solar systems provide numerous advantages, including reduced fuel costs and engine wear while simultaneously reducing noise, reducing carbon emissions and improving the performance of onboard electrical appliances for improved driver comfort and ultimately, greater driver retention.
Make sure to do your research when you are looking into brands of onboard AC power technology. You want a company that has a variety of products used in many different applications in the RV, marine, military, construction, EMS, bus, work service vehicle and commercial truck markets.
You need to work with a vendor partner who ensures its products are put through extensive reliability testing. A reliable partner will ensure its products are adequately certified to with various regulatory standards. And if you are adopting green technology, you need to work with someone who meets or exceeds the requirements for safety, quality, efficiency and the environment. Upgrade your options, increase your efficiency and look into advances like lithium-ion tech.