Eight months after its introduction, Liberty Coach’s new energy system – the first ever to meet the EPA’s stringent Tier 4 emissions standards – continues to electrify the Prevost universe, thanks largely to the unparalleled performance of the breakthrough lithium ion batteries designed and produced by Volta Power Systems. Recently we had the chance to discuss the system as well as the technology behind it with Jack Johnson, co-founder of Volta and one of the foremost authorities in the field of automotive grade lithium ion battery technology.
Please give us a brief explanation of lithium ion battery technology.
To answer your question, we first have to ask one of our own: What type of lithium ion? In fact, there are seven different types of commercially available lithium ion batteries now on the market. Each has unique properties that meet the needs of specific applications, similar to different types of fuel like diesel, gas and propane. Volta employs the same technology automotive companies utilize in hybrid and electric cars. Think Toyota Prius, Chevy Volt, and Tesla.
What makes automotive lithium ion technology so well-suited to powering a coach?
Higher energy content, longer useful life, and an original design expressly devised to power large loads, like air conditioning – it’s that combination that makes automotive lithium ion ideally suited for motorcoaches.
How do Volta’s batteries compare to traditional lead acid or AGM batteries?
It’s hard to compare our lithium ion to lead acid, because the chemistries are entirely different. To illustrate the difference as simply as possible, imagine a lead acid or AGM battery as a bathtub sized container full of energy. You can fill or drain that bathtub with a garden hose, which would take some time … and since you can’t get much water through that one small hose very quickly, it can’t deliver much power. Now imagine packing that same energy in a much smaller container – like a bucket – and instead of just one garden hose, you have seven to channel the flow of energy in and out. That’s lithium ion!
And again, the Volta solution takes those characteristics several steps further. Our batteries store more energy in a smaller space, charge far faster, and can deliver more power than other lithium ion solutions.
So what can your batteries do that AGM batteries can’t?
Again, there’s really no comparison. Here are a few of the most obvious differences:
Lifetime: Lithium ion batteries are designed to achieve 2,000+ cycles and still have 80% capacity remaining at that mark. Compare that to lead acid batteries, which usually only hit 50 to 250 cycles before they have to be replaced.
Charge rate: Lithium ion batteries can charge over 7 times faster than lead acid.
Power: Unlike lead acid batteries, whose power fades as voltage drops, lithium ion puts out consistent power over its full range.
Weight: Volta’s technology requires just 1/6th the weight of lead acid to produce a comparable amount of energy.
How exactly does the Volta system enable the coach to meet Tier 4 emissions standards?
In general, think of it as hybridizing your generator. Traditionally generators are sized to twice their required standard load because they need enough power to handle surge loads that come from motor starts and other large loads. But the Volta system has the superior energy and power needed to manage the peak loads and so reduce the demand on the generator. For example a 10kw generator can do the work a 20kw generator could traditionally cover. This allows the selection of a smaller generator that falls under the Tier 4 emissions requirements.
Better yet, there’s no need for the generator to idle. It only kicks in when it’s time to charge the lithium ion pack, meaning it will go to max power and run at its most efficient rpm. This keeps the generator cleaner, with less wear. It also reduces generator fuel consumption. And emissions are greatly reduced.
We know about motorcoaches as well as hybrids and fully electric autos like Tesla. Where else can we find your brand of lithium ion batteries at work, and where can we expect to see it pop up in the near future?
Currently, Volta technology is powering hydraulic boom trucks used by electric companies to service power wires. They can run all day or night without bothering customers with the engines at high idle. In the near future, you will also see our solutions appearing in the broader RV market as well as marine applications, home solar systems, over-the-road trucking, and even hydraulic liftgates used in the trucking industry.
How about the immediate future of motorcoaches? Frank foresees a day when everything will be powered by batteries alone, and the role of the generator can be reduced to simply recharging the battery packs. How about you?
We are essentially already there; the technology certainly is. I think it’s now up to consumers to become comfortable with the new possibilities this technology offers them. I believe with the energy density becoming greater, we could see generators completely eliminated from coaches because we will be able to store more energy onboard than water … and so like water, you could bring your electric energy with you. Right now, with the efficiency of our alternators on the main engine allowing for extremely fast recharging, the need for a generator is being reduced to extra redundancy only.