Thoughts (and Guesses) On A Big Box Budget Ebike

March 8, 2017
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Editor note this story was written by respected ebike community member George Sears.

Storm Sondors is going to make a $10,000 electric car. So he says, and he’s raised a million dollars. It will have a range of 50 miles, if you buy the least expensive one. In many ways, that sounds exciting. A little commuter car, something you might be able to drive in bad weather, carry stuff, etc. There is a Sondors ‘magic’, so it might sell. Of course, if you want a $10k electric car, you can get a used Nissan Leaf for about that, and some of them are quite new. The Leaf says a lot about the value of electric cars to people in the US.

The Chinese have a government that shapes economic policy, far more than in most countries. They have a ‘plan’ to get 4 million electric cars on the road by 2020. (This article says 5 million). GM is talking about tiny numbers for their 200-mile range Bolt. The bottom line, Americans are completely out of the loop on electric vehicles. GM will sell you a very nice Duramax Diesel heavy duty truck, a Denali with every gadget they can think of, and it may cost $70k and up. That’s where the American market is. That is where the profits are. Are we at risk of losing the edge as electric overtakes fossil fuels? That’s a political question, and it’s hard to project out into the future and say what the final outcomes will be. There are too many variables, starting with the price of gasoline.

To say the electric bikes are not understood by Americans is an understatement. You start out with a high level of indifference and hostility to bikes, and then add the complexity of what the motor actually does. On top of this, the battery tech has only emerged in the past few years. The bikes are unbelievably refined, even in a basic configuration, and an ebike is at the outer limit of efficiency, at low speeds.

It may be better to view this as a big picture problem. People don’t understand ebikes, but they don’t understand electric vehicles. This really comes down to not understanding batteries. The motor tech to build a decent electric vehicle has been around for a hundred years. While electric motors are more refined today, gasoline engines are incredibly more refined that the gas engines of the 1900’s. Electric only wins because of the energy costs, and the cost of batteries to store electricity.

It’s sort of curious, what is going on in batteries. Late last year, people started noticing how much battery capacity China was building, and building to go online in a couple of years. That amount dwarfs the Reno Gigafactory. But now Elon Musk is talking about a couple more Gigafactories, so the battery output numbers are going exponential. The short answer to ‘why?’ is that planned 4 or 5 million electric car number in China. If the Chinese do that, they will be the electric car economy, and they will be the ones learning all the hard lessons and all the tiny details of making great electric cars. It’s tough to believe that GM will be in any kind of position to ramp up the Bolt. You also have heavy truck and bus platforms that leverage electric technology far better than autos. A garbage truck or bus runs all day, so the savings are magnified, even if the initial costs are high.

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When you look at things with this broad perspective, the one conclusion you have to reach is that energy storage is absolutely and positively right on the brink of overtaking fossil fuel energy in actual use. It’s a total cost picture, and for electric, that is storage plus generation costs. Storage tends to drive solar, because solar needs storage, so everything feeds on everything else. Solar is clearly dropping in price. They built a solar farm a half mile from my house, but the manager told me they can’t build any more, because they can’t distribute the power.

It’s time to bring this discussion back to e bikes, and to ask practical questions about why e bikes don’t sell in the US. The stated goal of the Chinese, as they build all these battery manufacturing facilities, is to cut the cost of storage by 50%. Again, that is in the 2020 time frame. Not all electric auto batteries would work in an ebike. The 18650 was something Tesla sponsored, but Tesla has gone to a bigger cell. LG Chem and GM are using a pouch cell that might adapt to heftier e bikes. BYD makes a cell that uses LiFePO4 and Magnesium, which isn’t terribly energy dense, but maybe it works well in heavy trucks and buses. But are ebikes, and ebike batteries, too expensive? How quickly have the economics changed?

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The ebike is really the lowest animal in the vehicle battery food chain. It was the first to work, as cell prices dropped, but it is the first to reach a kind of price saturation. Assuming a 3500-mAh cell is good, no matter what comes along, you need 52 cells to put together a battery that works for most ebike designs, even the most aggressive.  It has a lot of discharge capacity and a lot of storage capacity. So if the cells are $4 each, the pack price (just the cells) is $200. At $1 a cell, the pack price is $50. You can’t get meaningful price cuts if you are in this capacity range. Another $50 cheaper? Not enough. If you put 6,000 in a car, yeah, it matters a lot. But not in a bike.

It may not do much good to try to adapt car batteries to ebikes. It seems like the 18650 cell goes in a lot of devices, so there are a lot of reasons to produce those cells. How much the lower cost of car type cells brings down 18650 cells is hard to say. There are always anomalies in markets. The 18650 might be a glutted market if car makers go to the new Tesla cell and pouch cells.

image06There is sort of a Walmart Effect for most goods. A new product starts out at higher end retailers, but prices drop. Walmart can only sell in a certain range of price points. Their bikes, for example, tend to be under $300. So at Walmart that is a premium bike. Can you try  to build the most minimal ebike on the premise this can lead to a huge ramp at the big box store level? It’s pretty clear from watching the online offerings that $700 is not that price. If you want to build a $400 ebike, even a decent one (the Sondors offerings) it can be done as battery prices drop. In a cheap bike, the cost of the battery is the most meaningful. A $4000 bike drops to $3900 if the cell prices drop by two dollars a cell. But a $500 ebike drops by 20%, to $400. These are very rough numbers, and the cheap bike will have fewer cells.

Anyone who watched the Sondors Fat campaign should have learned a lot about e bikes. image03There is a ‘cost of parts’ analysis. There is a frame, the tires, the rims, the handlebars, all the little parts. And a lot of these parts are cheap in China. Sondors changed things, because it made people aware of parts and prices. This was especially true of motors and lithium cells. What did he pay for his motor? What did he pay for his cells? You can make educated guesses. Sondors put all the pieces together to make a mass market ebike, a million unit type ebike. But there were too many problems.

In fact, there was an interesting discussion back when the Sondors came out,  as the Indiegogo campaign was ending. The Sondors campaign was unbelievably controversial. Some people said, over and over, everything about it was a fraud, that Sondors was not building any bikes, just leading people on. But in that heated atmosphere, with the campaign members tearing each other apart, how many would he have sold with a more subdued environment?

The dynamics of any crowdfund campaign are pretty far out of the mainstream. By pushing the promotion into social media, Sondors, or really the ad agency, Agency 2.0, got more visibility than any other ebike ever got. Ask yourself, does anyone know what a Haibike is, what a mid-drive is? But much of the publicity turned bad, so with Sondors it was a two edged sword. The Ad agency was, as all the partners hammered away at each other,  telling people what a horrible guy Sondors was. This was right in the middle of the campaign. Agency 2.0 went to court to get a lot of money, enough to shut Sondors down.

In the end, the Sondors fat bike was a $700 bike, just because of the 40% shipping charge. That was a good price, especially for a fat bike. But that shipping charge is something Walmart can control. They have their own trucks and distribution centers. You could make a nice bike today for less than the total cost of the Sondors Fat, with some high volume and a good battery design that measured up to safety standards. With a more efficient bike, mostly slimmer tires, you can get better performance from fewer cells in the battery pack.

Sondor has the “Thin”, but there he had a very basic bike, a basic ebike, and no one knows what an ebike is. He didn’t have a campaign, and there was nothing to bring new people into the market. So, he sold a lot of bikes, relatively speaking, but it wasn’t the breakthrough.

People buy stuff from big box stores. They don’t check out CF campaigns where the bike will show up 9 months later and they won’t refund your money, no matter what. You have to believe ‘enough’ in e bikes to accept that basic versions, basic e bikes,  do most of what an ebike can do. It’s a bike. If you want to go 15 miles an hour, not worry about most hills, and not worry about most headwinds, the basic motor and the basic battery gets you there.

At some point, somebody should try to make a bike with a $100 battery pack and a 350 watt motor. The idea would be to take a decent $200 bike and electrify it to the point where it made riding pretty much ‘no sweat’, even if it was designed to go (only) 15 mph. A $100 battery pack is a moving target. No one lists cell prices in a way you can say what 20,000 NCRB cells would cost.  But assuming I could get those cells for $2, and I made a pack with 20 cells, I could put something together for way under $100.
image01You might say, as an ebike sophisticate, that is nowhere near enough range, not enough cells. That’s not the point. The point is to get people to ride 5 miles, or 10 miles, just to get familiar with the tech. The real point is that some cells can be run down and still maintain an output rating, and 350 watts is not much with two rows at 36volts. If you make this bike, you probably need to sell it at a big box store. And they need to promote it, demo it.

I’ve made a bike that is close enough to what I describe to think it is possible. I have a Bikes Direct bike that shows the basics of building an ebike. The bike, a Mango Cruiser, was $270 with the shipping. Without the shipping, the fenders, and the gears, it’s a $200 bike. It’s not much fun to ride up any hill. ANY hill. I put a premium motor on the bike, a Golden Smart Pie. I have run several batteries with the bike, but the most basic is a pack constructed of 24 Sanyo GA cells from Titan Flight RC packs. Basically the 22 volt packs are put in series, making 44 volts, and then two sets of the 44 volt packs are paralleled.

That is 24 cells. Dropping to 20 cells would be a 36v nominal pack. The GA cells, two rows, can deliver 20 amps, which is around 900 watts, in my configuration. With a motor limited to 350 watts, the pack should deliver 10 amps, 5 amps per row, for most of the capacity. So I get an easy 10 miles out of the pack using somewhere around 200 watts, on average.

image02My experience says that 24 cells works with a motor that delivers 750 watts and a bit higher. At the end of the charge, when the SOC is low, the pack still works quite well, even though the voltage is low. My guess is that  a 20 cell pack would work for people where all you wanted was to encourage them to ride. A pack for a 350 watt bike and a 12 mile range.

The idea would be to make a 36V and 7 amp-hour pack, or less if 3000-mAh were a good deal.  This is not a severe limitation. If the pack cost $89, people can have a couple of packs. Production is automated.

(How safe can you make a set of 20 cells? It is tough to ship battery packs, but it is easier to ship smaller ones. Is there enough history to point to ‘all’ the failures and say what went wrong? It might be possible to wrap the pack in something relatively fireproof. If I am making packs from RC suppliers, how do they get away with it? I wouldn’t say my pack is safe, but it’s like the lithium cells in power tools or loose cells on Ebay. I don’t know when everyone has to follow more stringent regulations.  )

 

image04If you take a $200 bike, like the Mango, and add a hub motor that costs maybe $45 wholesale, what would you have? The motor would not be powerful, but it would double or triple the power the unfit rider provides. That’s a central idea. You build a bike that makes basic riding very easy, with modest pedaling by the rider.

So I see a Mango type bike with a motor and controller coming in around $350. But with super volume prices, quite a bit lower. The battery cells might run $50, so the question is how much the case costs, and how simple you could make it, how to make it ‘safe’. A solid metal case? Chargers are not expensive if you buy 10,000.

Getting back to the basic premise of this article, the demographics. People have ignored the low end, or maybe it hasn’t worked out very well. People don’t know electric bikes. You can’t expect a lot of interest in something people don’t even know about. I see the transformation as being something very fundamental. Once people have access to electric bikes for maybe $150 more than a cheap Walmart bike, that’s it. That’s the end of the low end bike. No one will want one, OK? I’m basing all this on one critical idea: The thing has to work.

Why will it work? Basically because you can get decent cells now, cells that will stand up for a year even with some punishment. People charge stuff, that is no big deal. Make a small battery pack and people will bring it inside. People won’t ride that far. Most of the bikes people buy at Walmart never get ridden. Talk about a win-win. Bikes that get ridden 5 miles!

This is what battery prices should drive. They should drive the almost total electrification of even the absolute most basic bike (for adults, at least). Not to suggest good road bikes or mountain bikes are obsolete, but it depends on the rider, that demographic.  It’s always a question of how well these basic bikes can work. But it’s going to be a basic hub motor. If you use decent cells, you get a decent performance level, assuming the pack is assembled well enough.  It might be smart to move to solid rubber tires, just from a maintenance standpoint. Basic suspension forks can smooth the ride. Make a bike that works.

People hate the low end, people hate the poor, so no one develops this stuff. The bike has to be designed for low maintenance. It just has to work as an ebike and not try to do much else. If you can meet this goal, you drive  the ebike into the economic mainstream, you can talk about what bikes can do for transportation. Let’s face it. Most people are not fit enough to ride a bike. It will never happen, no matter how many bike paths you build. But if you build cheap e bikes, and they really work, you change the transportation dynamic as well.

My advice? Go low. Make all bikes ebikes.  This is a $200 bike made into an ebike. It’s better to use an ebike frame, something with mounts for the motor.

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Reference — Speed and Watts
This references the chart, below.

At low speeds an ebike uses very low watts and watt hours per mile. At 14 miles per hour a bike needs 150 watts (ideal circumstances). If the motor does all the work, it means about 11 watt hours per mile. In the earlier discussion, the 20 cell battery has about 200 watt hours, which means a range of 18 miles with no pedal effort. With moderate pedaling, the rider can do a lot of the work and extend this range. Make no mistake, this is 14 mph. This is where a $400 ebike makes the most sense.

The chart below assumes a somewhat fit rider who contributes 100 watts. An out of shape rider may only contribute 50 or 75 watts. These are the riders who give up when they hit a hill. The idea is to give them another 200 watts to get up hills, not make a fast bike.

The chart is based on ‘best guesses’ and every bike is different. The obvious point is that the way to buy range is to design a bike for low speeds. Ideally, people go out for exercise and let the motor help. The chart shows that at 14 mph, the bike uses 11 watt hours per mile, and at 28 mph, it uses 25 w/h. This is without pedaling, which is up to the strength of the rider. At 14 mph, even with a tiny battery, it is possible to ride for more than an hour.

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Written by George Sears, March 2017 


1 Comments

  1. Fantastic article! Thanks for the charts and numbers. I want to build a commuter bike for work but if ebikes start getting mass produced it will help the whole market compete.

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