A Butane Recharger for Your Cellphone

A USB-based fuel cell system will recharge your portable electronics for pennies

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Steven Cherry: Hi, this is Steven Cherry for IEEE Spectrum’s “Techwise Conversations.”

We live in a miraculous age in which we can carry computers around in our backpacks, pockets, and pocketbooks. But portable devices are only as good as the power within them, and as they get more powerful, they need more and more power.

Battery technologies keep getting better but still aren’t better enough for 14-hour flights over the Pacific or watching the Olympics all day on a cellphone.

For decades, we’ve dickered with fuel cells, mostly based around portable proton exchange membranes [PEMs]. But even the military, which has been more interested in portability than anyone, doesn’t use them much.

One company has been working on a different strategy that would use butane, the same substance we walk around with in our cigarette lighters. Back in 2008, my colleague Phil Ross looked into it and declared it a loser for our then-annual look at the upcoming year’s highlights and lowlights.

Longevity was one issue. Phil asked how “the electrodes could last through many heating and cooling cycles, which would cause the ceramic and silicon layers to expand and contract at different rates?”

Then there were what Phil called the marketing issues. “Can everyday users be trained to carry fuel around? To stock up on cartridges of it and keep them in their desk drawers, briefcases, and glove compartments?”

We do all that with batteries, but batteries are so generally useful that you can buy them in every airport shop, drugstore, and gas station. Will retail outlets in out-of-the-way places stock butane fuel cells? Phil wondered. Will fuel cells be allowed past security at airports?

The company we singled out as most promising, but still a loser, despite an MIT pedigree and US $40 million in start-up funding, was Lilliputian Systems, based in Wilmington, Mass., which is about 15 miles north of Boston.

The company recently announced a partnership with Brookstone, the company whose airport stores many of us have probably stopped in at one time or another, for its first commercial product release early next year. My guest today, by phone, is Mouli Ramani, Lilliputian’s vice president of marketing and business development. Mouli, welcome to the podcast.

Mouli Ramani: Thank you. It’s an absolute pleasure to be here.

Steven Cherry: So I walk into a Brookstone store and buy this. What exactly am I buying, and how do I attach it to, let’s say my iPhone?

Mouli Ramani: Well, it’s important to make the distinction as to what our technology is, which we’ll go into a lot more detail in this conversation, and what the first product is. The first product, what you will be able to purchase as you walked into a Brookstone store, is a stand-alone device. We’re working with our marketing friends to find out exactly what the go-to-market name will be. What we’re calling it currently, as a working system, is a “USB mobile power system,” and it’s a very descriptive name, because what it is, it attaches to your phone, your Bluetooth headset, your camera, anything frankly that you can charge with a USB port, and it provides power to recharge the internal battery of that USB device. That’s what you’re purchasing when you walk into that Brookstone store, and it comes initially, as you stated before, with a butane cartridge—a cartridge that contains a fuel that we use in our fuel cell to convert it into electricity. And you’ll also be able to purchase on subsequent trips, either through the Brookstone store or through the website or via the catalog, or frankly via any number of different channels, replacement cartridges that would also give you one week to two weeks of power in your single device.

Steven Cherry: So do you have a sense of what I’m going to pay for, I guess, the system initially, and then the cartridges?

Mouli Ramani: Well, we’re not making that announcement yet. We’re working with Brookstone. We’ve got a very good idea what the range is, but we’re not making an announcement on that at this point. That announcement will come later in the next several quarters, but it is not meant to be a high-end device that sits only for the übertravelers or the jet set or the literati. It’s meant to be a mass-market device, and it’s going to be priced as a mass-market device. The cartridges themselves, they’re going to be comparable to buying a cup of coffee at your local coffee place. So that’s the kind of area we are, and just one quick correction to your introduction: We haven’t even announced when it’s going to be available.

Steven Cherry: Fair enough. So what kind of charge do I get for my cup of coffee?

Mouli Ramani: Excellent question. So what we have per cartridge is about 14 charges of a modern smartphone. An iPhone is a good example, or your latest Droid 4s or Droid Pros, in the neighborhood of 14 full charges, meaning you could drive those phones down to zero—meaning completely dead—and you could charge them up to full 14 times on any single one cartridge.

Steven Cherry: So each charge costs me a couple of sips of coffee.

Mouli Ramani: Yeah, exactly. My tongue-in-cheek marketing program that I’m working on right now is to show one of our cartridges next to a cup of coffee and saying, “one charges you for about two hours, the other charges all your consumer electronics devices for two weeks. It’s basically your choice.”

Steven Cherry: So tell us exactly how this works, and let me just start with, Why butane? Were you thinking about all the disposable cigarette lighters out there?

Mouli Ramani: Well, it is a very very good question. First of all, we’ll get, I suspect, into the technology a little bit more. We’re a solid oxide fuel cell, which does, as you pointed out in your introduction, does differentiate us from the proton exchange membrane fuel cells that are out there. And unlike most PEM cells, where you’re required to use methanol, as an example, for your input fuel, we operate at a really high temperature, so we can operate on any hydrocarbon. You could put methanol; you could put butanol; you could put butane. As I like to sometimes joke, it’s like Mr. Fusion in the old Back to the Future days. You could put bananas in there, because we’re breaking down these components at such high temperatures into their constituent fuels such that we’re able to turn them into electricity. So the technology can support any hydrocarbon, but our first product is exclusively butane, and butane was chosen for a number of reasons. First of all, it’s got an incredibly high energy density, on the order of 7400 watt-hours per liter, approximately. But maybe even more than that, an incredible safety record as well. Over 100 years of widespread consumer use in lighters, cooking, lighting specialized application—in fact, most people, if they’re unaware, most spray cans people used in the old days, when they had those ozone-depleting CFCs as a propellant, those have largely been replaced with butane on it, so you’re carrying butane onto an airplane when you’re bringing your hairspray onto a plane. So it’s the high-energy density, it’s the impressive consumer safety record, and what I believe is very important is that people are comfortable with butane.

Steven Cherry: And just to be clear, you say the technology can support all sorts of substances, but this is not like when you would pour butane from a can into a nondisposable cigarette lighter. This is like a self-contained sealed unit right?

Mouli Ramani: Correct. It’s a self-contained sealed unit that you would purchase at a Brookstone store or any number of new partners that we’ll announce over the next several quarters and years. You would buy it—it’s a self-contained unit—you would attach it to our device or devices, and it would, through a mechanism where we have a valve that extracts the butane out of it when it connects to our device, would power the fuel cell. Once that cartridge is empty, you just toss it into your recycling bin, much like you would a water bottle or anything of that nature, and you would go buy another coffee-cup-priced, approximately, cartridge of butane, and you would carry on your way. And having it sealed as such, and having it recyclable as such, has been a big part of how we’ve gotten our regulatory approval to take these on airplanes, to use these on airplanes, and use them in our military applications that we’re doing with our partners as well, too.

Steven Cherry: So how does this compare with the proton exchange membranes? First of all, remind our listeners of how those work and then how this works.

Mouli Ramani: Well, PEM fuel cells usually have methanol as a fuel source. Like most fuel cells, they don’t actually operate on the methanol. It’s hydrogen, the mobile ion, that is of relevance, is, in fact, the hydrogen ion. So the first thing that you’ve got to do in a PEM fuel cell is you’ve got to actually extract the hydrogen ions from your source gas or source material—in this case methanol. And so we call that the type of preprocessing efficiency. There’s losses, because you’re not actually using all of the methanol. Then you have to take that hydrogen and turn it into electricity. You actually have to turn those hydrogen ions into an electrical current; that’s what we call a core fuel cell efficiency.

And then you’ve got to actually have at a system level an efficiency of how well you’re able to convert that directly into whatever it is you’re trying to recharge. So if you stack up all of these efficiencies in PEM fuel cells, and any fuel cells, including ours, you actually have a derating of how much energy you begin with and how much energy is actually delivered to the consumer at the end. And so the direct answer to your question is, PEM fuel cells, I think, have largely been unsuccessful in the marketplace—technology is fantastic, but unsuccessful in the marketplace—largely because when you do all of these deratings elements—preprocessing efficiency, core fuel cell efficiency, and system electrical efficiency—and then if you kind of want to add a volume efficiency because you actually have to carry this around, when you add all of these deratings, PEM fuel cells do not operate as well, or maybe just marginally better, than a lithium ion battery. So in the end, you’ve gone through all of this exercise to deliver something that, in the end, isn’t that much better, if better at all, compared to the technology it’s trying to complement or replace depending on the application. And I think that’s the No. 1 reason why you don’t see PEM fuel cells largely deployed in consumer or military applications.

Steven Cherry: We wrote about a company that looked to have a promising portable fuel-based charging system—Medis Technologies—back in 2009, but they went out of business. I guess they used borohydride. Do you have any serious competitors now?

Mouli Ramani: The No. 1 competitor, if you look at an industry level, is the lithium ion battery. The lithium ion battery is 90-ish percent of the market, and that’s why fundamentally, frankly, we think the first product that we’re coming out with is a recharger of the dominant industry player. To demonstrate that we have this energy-efficiency advantage, and secondly to demonstrate to the industry at large that people, we believe, based on all the reports and all the surveys we’ve done, would actually love to have this kind of product and are perfectly happy carrying butane around.

But as we move down the path, we hope that we can start integrating our core technology directly into the consumer electronic systems. So we don’t really foresee a long term, our vision of being the stand-alone device that recharges devices, but rather integrating our technology directly inside. So in that large scale, we’re playing in the same space as lithium ion batteries and lithium derivations thereof, lithium polymer, etc., batteries. That’s where we think the competition is. If you really look at fuel cells, and if you look at the fuel cells we compete against, what we’ve seen is primarily a huge level of investment down the PEM area, and to the extent that other technologies are being investigated, they’re usually focused at automotive or home or larger spaces. To that extent, we see a lot of fuel cell competitors in our space and our power level, we really see lithium ion being our fundamental competitor that we work against.

Steven Cherry: Lilliputian has a partnership with Intel. What’s their interest in this area?

Mouli Ramani: Well, that’s actually one thing I’m very excited about. So, until very recently, Intel had basically been making products for one company in the entire world: Intel. They’d not really gotten on this outsource-fab model that a lot of other companies in Asia, for instance, went down the path. But we started working with Intel. I mean, our core technology is our ability to imprint a fuel cell directly onto a silicon wafer, if you want to think of it in very short order, and then imprinting that on involving the electrochemistry and the structure. So when we first started talking with Intel, they got very excited about the possibility, and when the conversation started moving forward, it became clear that they really wanted to be part of the solution that we’re bringing to the market. So what Intel has done with us, and we made this announcement in late 2010, is that Intel is retrofitting one of its fabs, a fab actually quite local to us in Hudson, Mass., spending several tens of millions of dollars to retrofit their fab in order to manufacture our fuel cells on their site. And secondly, what they’ve done is they’ve taken a significant equity portion of the company as well, too. So Intel is both an investor and a supplier for Lilliputian now.

Steven Cherry: Well, I wish you the best of luck. Nothing makes us happier at Spectrum than when a loser becomes a winner, because we love technologies to work out, and you… Actually, a lot things make us happier than admitting we’re wrong, but we still wish you the best of luck.

Mouli Ramani: Thank you so much. My wife wants me to turn into a winner as well, too, so we have that in common.

Steven Cherry: Very good. Well, thanks for being with us here today.

Mouli Ramani: Thank you, Steven. Bye bye.

Steven Cherry: We’ve been speaking with Mouli Ramani of Lilliputian Systems, which is releasing a butane-based fuel cell for smartphones and tablets early next year.

For IEEE Spectrum’s “Techwise Conversations,” I’m Steven Cherry.

This interview was recorded 14 June 2012.
Segment producer: Barbara Finkelstein; audio engineer: Francesco Ferorelli

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