Questions people usually ask about electric bikes and cargo bikes

Do you recharge the battery by pedaling?

No. I recharge my ebike by plugging it in at night. On an electric bike the pedals directly drive the rear wheel and the electric motor also drives a wheel; at no point do the pedals drive a generator for recharging the battery. The ebike can be moved forward by either the motor, the rider pedaling, or both at the same time. The batteries can only be charged by plugging them into a charger or by regenerative braking (see below).

How long does it take to recharge the battery?

A typical ebike takes four or five hours to recharge, but custom batteries and chargers can take much less time.

Can you recharge the battery by braking? That is, can you use the motor as a generator to slow you down?

This is certainly possible—some bikes have “regen” braking—but for technical reasons it’s debatable whether the expense is worthwhile. I recently added regen to my bike and I find it very useful for descending Ithaca’s steep hills and for slowing down before turns. And on a typical trip it gives back about 10% of the energy I use. My bike probably cost $100 or so more to have a regen-compatible controller and a handlebar-mounted button. I like regen for the braking function, but it’s not worthwhile solely for increasing my bike’s range. I can more easily increase my range by carrying a battery that is 10% larger.

How fast and how far can it go?

Ebikes are legally limited to 20mph. But even if they didn’t have this limit, they are typically only powerful enough to go 15mph to 25mph. The range of an ebike varies depending on how much you are willing to pedal versus how much you use the motor. A typical ebike pedaled by a typical person has a range of 15 to 30 miles. Of course, you can always increase your range by carrying more batteries.

What is a cargo bike?

A cargo bike is an extra larger and sturdy bike designed to carry passengers and hundreds of pounds of cargo. The boundaries between different categories of cargo bikes are somewhat blurry. Bakfiets and longjohn cargo bikes have the load in front of the driver. The bakfiets tends to have a box, often equipped with amenities for carrying kids. The longjohn usually has a flatbed platform. Work bikes also have the load in front, usually in a box over a small front wheel. Longtail bikes (most famously the Xtracycle brand) have the load in the rear, on an extended bike frame. Longtails are the most stable, so they are the safest cargo bike for hilly Ithaca. And electric motors are pretty much a requirement for cargo bikes in Ithaca. Read more about cargo bikes here.

How much does it cost?

An ebike can cost anywhere from $1,000 to $4,000. The lower price is what you would pay to convert your regular bike to an ebike by installing a $500 hub motor and a $500 battery. The higher price is what you would pay for a full-featured electric cargo bike with family-carrying accessories. A better financial question, however, is “How much money can I save by using an electric bike?” (see below).

 

Questions people should ask about electric bikes

Okay, how much money can I save by using an electric bike?

According to the AAA in 2011 a typical family will spend $9,859 a year to own and operate a car over a five-year period. In contrast it costs about $520 a year to own and operate an ebike—about $500 a year to buy and maintain the bike and a trivial $20 a year for electricity. So if you can completely replace your car with an ebike you could save about $9,859 – $520 = $9,339 a year. However if like most people you still want to own a car, using an ebike to cut just your operating costs in half can reduce your  car costs by about $1,700 a year, for a savings of $1,700 – $520 = $1,180 a year. A third option, which gives you the convenience of using a car without the expense of owning a car, is to use a carsharing program. This third option can easily save you thousands of dollars a year depending how often you need to use the carshare car.

How important are electric bikes?

Bikes have always been important: they take up less space on our roads than cars, they use fewer resources, they keep us fit, and they don’t pollute. However, the biking lifestyle has not been possible for everyone until very recently. Several technological advances, including more powerful batteries and electric motors, make possible large electric bikes and small electric cars that have the utility of a gasoline-powered car in every respect but speed. Electric bikes are a world-changing phenomena, and unfortunately one that is passing by the United States.

Environmentally speaking, isn’t an electric bike a step backwards from the regular bicycle?

It may seem self-evident that the electric bike is less environmentally friendly than a regular bicycle. An ebike uses energy and a regular bike doesn’t, right? In fact, a regular bike does use energy in the form of food. If you factor in the energy required to grow and distribute the additional food required by the bike rider to power the bike, an electric bike can be more efficient than a solely human-powered bike. It’s a close call, however, and someone who eats local foods may win the efficiency prize. For a quick analysis see http://www.ebikes.ca/faq.shtml#quiz8 and for an in-depth analysis see http://www.ebikes.ca/sustainability/Ebike_Energy.pdf.

How much energy does an electric bike use compared to other modes of transportation?

If we were to rank modes of transportation we would have bikes (both regular and electric) at the top, walking takes twice as much energy, the train takes four times as much energy, and driving a car takes four hundred times as much energy.

What kinds of batteries are available?

Electric bikes no longer use lead-acid (car) batteries. They use various kinds of lithium batteries instead. See our ebike battery FAQ below for details.

Can you power them with solar power?

Yes! An electric bike uses so little electricity that it can easily be charged for a day of use from a 250 watt solar panel. A typical 250 watt solar panel is about the size of a door and costs $300. For comparison an electric cars uses about 1,200 Wh/mile of energy while an ebike uses about 20 Wh/mile. If we charged both the electric car and the bike each from 250 Wh/day solar panels on the roof of our house, we could power the car for 0.2 miles and we could power the bike for 12 miles. See my solar-powered bike experiment which provided about one fourth of the power I used on a 250-mile bike trip.

How much can they carry?

A cargo bike is a bike designed to carry passengers and heavy loads. An electric cargo bike is, not surprisingly, a cargo bike with an electric motor. A typical electric cargo bike can carry on the order of 500 pounds. That’s half the load of a typical “half-ton” small pickup truck. That could be one adult rider, two small kids, and a week’s worth of groceries. It could also be many other surprising loads. Cargo bikers love to push the limits of what they can carry and then photograph and brag about their accomplishments.

Are they convenient?

Yes. Simply plug in your battery while you’re asleep, and ride while you’re awake. You can perform most maintenance tasks yourself with a few simple tools. And perhaps the biggest convenience is parking: with a bike you can travel literally door-to-door. In fact when you factor in parking, a short bicycle trip in a city can outperform the same automobile trip in terms of total trip speed, cost and convenience.

Are they safe?

Yes. Injuries and fatalities per trip are much lower for biking than driving. Some biking enthusiasts go so far as to say that not biking is not safe. If you look at the health benefits of biking, they argue, not biking puts you at a higher risk of various life-threatening diseases. A powerful electric bike is (perhaps counter-intuitively) safer than a human-powered bike because you can keep up with traffic so that cars do not need to pass.

Are they legal?

Yes. Electric bikes are legally defined as bicycles at the federal level. So electric bikes can be used anywhere and in any way that bicycles can be used. Some states have also drafted legal definitions of ebikes similar to the federal definition. For states that haven’t yet drafted an ebike definition (such as New York State), the federal definition applies.

What are the drawbacks to using an electric cargo bike?

The main drawbacks are riding in the winter and riding in the rain. For many this is reason enough to own a car or to have a carshare car or public transportation as a backup vehicle. For others, harsh weather is a challenge akin to camping, a situation to be conquered by judicious use of cordura and goretex. One advantage electric bikes have over regular bikes is that the same battery used for propelling the bike can also be used for lighting and for heating the biker; motorcyclists have evolved heated clothing technology that ebikers can use.

What’s the difference between power and energy? What are amps, volts, and watts?

It’s useful to know a few abstract electrical terms in order to be able to think about concrete things such as “does my ebike have enough power to get home?” Learning this stuff may be intimidating at first but consider that most people have mastered similar car-related terms such as mpg and mph.

Power (in horsepower or watts)
Think of power as measuring how fast your bike can go or how well it can get up a hill. Volts and amps multiplied together tell you how powerful your ebike is in watts. A standard Boxy Bike kit uses a 36 volt battery and has electronics limited to 20 amps. So our bike kits have up to 36 times 20 = 720 watts of power. That’s about one horsepower. It’s possible to substitute higher-power components for a more powerful ebike.

Energy (in watt-hours)
Think of energy as the amount of “gas” in your “gas tank”. A battery’s volts times its amp-hours rating gives the “size” of your gas tank in watt-hours. A standard Boxy Bike kit has a 36 volt battery with a capacity of 10 amp-hours, so it can store 360 watt-hours of energy. A typical ebike uses 20 watt-hours per mile, so this battery can take you 18 miles (360 watt-hours divided by 20 watt-hours per mile equals 18 miles). In actual practice an ebike’s range depends on the terrain you are biking over and the amount of weight your bike is carrying.

What kind of batteries do ebikes use?

In the past ebikes used lead acid batteries, also known as sealed lead acid (SLA) batteries. This is the same kind of batteries that cars use. However, in western countries SLA batteries have largely been replaced by various kinds of lithium batteries. Lithium are better in every regard except price. Lithium batteries cost three or four times as much as SLA but they are lighter, more powerful, and last longer. Also, lithium batteries usually have a “battery management system” microprocessor built into the battery that protects the battery.

What kinds of lithium batteries are there?

Lithium batteries come in several different chemistries and form factors, and newer and better types are constantly being developed. LiFePo4 batteries refer to batteries with a lithium iron phosphate chemistry. These batteries are optimized for longevity and safety and have been the standard ebike battery chemistry for many years. More recent batteries that are similar to but somewhat better than LiFePo4 batteries include LiMn (lithium manganese) and LiNiMnCo (lithium nickel manganese). The word “lipo” refers to lithium polymer batteries wrapped in a foil pouch. These batteries are optimized for light weight, and don’t have protective circuitry. Small lipos are used in mobile phones and laptops; larger ones are used by model airplane hobbyists. Ebike hobbyists have figured out how to use them to power extreme custom ebikes. Early lipo batteries had a lithium cobalt chemistry, but now many other chemistries are used.

Are ebike batteries safe?

Yes. Batteries intended to be used as ebike batteries have a protective circuit board in them that  prevents them from over-discharging and overheating.

How do I care for my battery?

Ebike batteries don’t require much more care than mobile phone or laptop batteries. Basic rules apply: don’t charge them with a charger they were not designed to use. Don’t drop or puncture them. Keep them indoors when temperatures fall below freezing.

How do I get an ebike?

Browse our bikes page. Then stop by our shop and pick one out.