Tag: Lithium-ion Batteries

Electric bike terminology explained: Jargon busting

The world of electric bikes is filled with jargon and it can all be a little confusing to those who are new to it. We hope to clear up some uncertainty around electric bike terminology by explaining the keys terms you’re likely to hear when researching ebikes.

 

TYPES OF ELECTRIC BIKES

 

First off, not all electric bikes are created equal. There are a few different types of electric bike, and they have certain features that set them apart from each other.

 

Pedelec (or EAPC)

A Pedelec, otherwise referred to as an electrically assisted pedal cycle (EAPC) is what many people think of when they hear the term “ebike”. It’s a bike with a motor that assists the rider’s pedalling – it does not provide assistance unless the rider is pedalling. In the UK and Europe, Pedelecs are limited to a power output of 250W (we’ll discuss this unit later) and 15.5mph (25kph), meaning the motor will switch off if the bike exceeds this speed. They’re legal to ride, treated exactly like a traditional pushbike in the eyes of the law. Our Furo X is a perfect example.

 

S-Pedelec

An S-Pedelec is much like a Pedelec, the key difference being the speed at which the electric motor switches off. S-Pedelecs assist the rider up to speeds of (45kph) and have a power output of 500W. Given this high-speed capability, they’re not legal for general use. In order to use one in Europe and the UK, riders will need to register and insure the vehicle and possess a driving licence. And yes, the “S” stands for Speed.

 

E-mountain bikes

E-mountain bikes (E-MTBs) are simply electric mountain bikes. As a result, they’re hardier than other ebikes, with better suspension, different tires and braking systems, and additional weight-carrying capabilities. As long as they conform to the EAPC standards, they’re legal to ride in the UK and Europe. Take our very own Sierra as an example.

 

Twist & Go bikes

Twist & Go bikes are bikes that you do not need to pedal in order to make them move. Much like a motorbike or moped, you simply twist the throttle in order to go (hence the name). These aren’t road legal in the UK and are treated the same as motorbikes due to the lack of pedalling involved.

 

 

MOTOR

 

The motor is a key component of an ebike. It’s the part that converts electrical energy, supplied by the battery, to mechanical energy. In other words, it uses the electricity supplied by the battery to help make the ebike move.

The following are terms that are closely associated with motors.

 

Power

Power is the rate of “doing work” or transferring energy over time. The more power a motor produces, the more energy it converts each second. To put it in context, more powerful ebikes are faster than less powerful ebikes because they produce more mechanical energy (or do “more work”) per second.

 

Watts (W)

Watts are a unit of measure used to describe the power output of a motor. The standard way of measuring power is in Watts.

 

Torque

Torque is the rotational power of the motor. The higher the torque, the more turning power the motor produces, and the better the bike is at assisting the rider. Torque is particularly important when travelling uphill.

 

Newton-metres (Nm)

Newton-metres are a unit of measure used to describe the torque output of a motor. In other words, torque is measured in Newton-metres.

 

 

BATTERY

 

The battery is the other key component of an ebike. It’s the part that supplies electrical energy to the motor. The following terms are closely associated with batteries.

 

Lithium-ion batteries

While there are many types of batteries, most ebikes use lithium-ion batteries (including our ebikes). They’re a type of rechargeable battery that’s very lightweight for the energy it provides. Lithium-ion batteries can be found in a range of electrical devices, including smartphones and laptops.

 

Range

The range is simply the distance an ebike can travel one a single charge. The range of an ebike will be affected by the size of the battery, how efficiently it uses power, its weight, the terrain on which you’re riding, the incline, and even the direction and strength of the wind. We designed an online range calculator to evaluate the range of light electric vehicles.

 

Volts (V)

A volt is the standard unit of measure to describe electrical potential between two points. In other words, voltage is the energy per unit of charge. It’s the “push” that moves electrical charges from one point to another (giving us a current).

 

Watt-hours (Wh)

Watt-hours are the unit of measurement used to describe a battery’s capacity. The higher the Watt-hours, the higher the capacity of the battery, and therefore the greater the range of the ebike (as a general rule).

 

Amps (A)

Amps are the standard unit of measurement for current, which is the rate of flow of electrical charge. The higher the amps, the faster the flow of electrical charge.

 

Ampere-hours (Ah)

Ampere-hours is a unit of measure that describes the rate of the flow of current over time. It can be thought of as the amount of energy that passes a particular point in an hour and is often used to describe a battery’s capacity.

 

 

OTHER FEATURES

As well as the technical, scientific terms, there are a number of features that are common to most ebikes. It’s helpful to be aware of them when you’re researching which ebike you should buy.

 

Walk assist

Walk assist is a useful feature that helps riders to move their ebike around when they’re unable to ride, or help them to start riding. The motor accelerates the ebike to a speed of approximately 6kph, making it easier when walking with the bike or when you’re just starting to pedal. It’s especially useful when you’re setting off on an incline.

 

Regenerative braking

Regenerative braking is another innovative feature that improves the energy efficiency of an ebike. When braking, kinetic energy is lost as you slow down. With regenerative braking, the ebike will store this energy instead of allowing it to be lost. In essence, it charges the battery a little each time you use the brake.

 

We hope this guide is useful and helps you to make a more informed choice of an electric bike. Start by checking out our very own Furo X, one of the most powerful folding ebikes you can buy!

Lithium-ion Batteries vs Hydrogen Fuel Cells in Electric Vehicles

Today, most electric vehicles use batteries, often based on Lithium-ion or Lead-acid chemistry. These batteries allow storing energy that was produced away from the vehicle and subsequently use that energy to create mechanical motion and make an e-bike, car or motorcycle move forward. Hydrogen Fuel cells, a rather old technology, created in 1839 by Sir William Grove and refined through the years, also allow storing energy in the form of hydrogen to power electric vehicles. Like a battery, a fuel cell harnesses a chemical reaction to produce energy in the form of electricity. More specifically, Hydrogen fuel cells generate electricity, water and heat from hydrogen and oxygen.

 

Fuel cells consist of an anode and a cathode surrounding an electrolyte called a synthetic polymer membrane which separates hydrogen and oxygen while only permitting the passage of certain ions (H+ or protons). Hydrogen atoms enter the fuel cell at the anode where they are stripped of their electrons. These electrons travel through the vehicle’s circuit to the cathode in the form of electricity. The positively charged hydrogen atoms (or protons) travel through the membrane to join with the oxygen and the electrons in order to eventually form water. Each individual fuel cell produces relatively low amounts of current and voltage and, like lithium-ion cells, therefore need to be stacked together in series and in parallel to reach the target voltage and max current required by the vehicle they are powering.

 

Hydrogen Fuel Cells vs Lithium-ion Batteries - Detailed functioning of a Hydrogen Fuel Cell

 

The beauty of hydrogen fuel cells is that you get electricity, heat and (potable) water as outputs with hydrogen and oxygen as inputs. Oxygen is abundant in the atmosphere while hydrogen is the most common element in the universe. However, hydrogen tends to bond very easily with other elements. Therefore, it has to be artificially isolated before being usable as fuel through processes that are quite expensive and energy-consuming.

 

Hydrogen used in fuel cells has the energy to weight ratio ten times greater than lithium-ion batteries. Consequently, it offers much greater range while being lighter and occupying smaller volumes. It can also be recharged in a few minutes, similarly to gasoline vehicles. However, Hydrogen fuel cells also come with a lot of drawbacks. First of all, hydrogen is mainly obtained from water through electrolysis which is basically a reversed fuel cell and takes electricity and water to produce Hydrogen and Oxygen. The source of this electricity can range from renewables to coal depending on where you are in the world, hence hydrogen extraction can be very clean or dirtier than a typical gasoline car. Nowadays, sadly, it is more likely to be the latter simply because of the way the majority of the electricity is produced on Earth.

 

Other issues are that storing hydrogen as a gas is expensive and energy-intensive, sometimes as much as half the energy, it contains, and even more so when it is stored as a liquid at cryogenic temperatures. In addition, it is highly flammable, tends to escape containment and reacts with metals in a way than renders them more brittle and prone to breakage. Eventually, although it is everywhere around us, hydrogen is hard, dangerous and expensive to produce, store and transport.

 

Fuel cells can also only operate with water, not steam nor ice. Therefore, managing internal temperatures is essential and heat has to be constantly evacuated through radiators and cooling channels which add considerable amounts of weight. Restarting in cold temperatures can also be very complicated and impractical in locations that often experience temperatures below freezing point.

 

Detailed functioning of a Hydrogen Fuel Cell

To conclude, hydrogen fuel cells offer a potentially very clean, energy-dense and easy to recharge energy source for vehicles and other systems, but are currently complicated, expensive and dangerous to operate. In comparison, Lithium-ion batteries, although less energy-dense and slower to recharge, are as clean, much cheaper, easier and safer to handle. More specifically, cylindrical lithium-ion cells like those used in the SIERRA and the FX are very stable and safe to use. In the future, once the technology is sufficiently developed and the drawbacks mentioned above addressed, hydrogen could be a great solution to increase range and decrease charging time in electric vehicles. But for now, lithium-ion technology is the best solution to offer very practical and high-performance e-bikes and other vehicles.

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