Dissecting "battery-rickshaws": How do they work?

Battery-powered rickshaws, commonly known as easy bikes or auto-rickshaws, have become an increasingly familiar sight on the busy streets of Dhaka and other cities across Bangladesh. These vehicles, which combine the traditional rickshaw design with electric motor technology, have significantly changed the urban transportation landscape over the past decade. While they offer a faster, less physically demanding mode of travel for passengers and drivers alike, their proliferation has raised questions about safety, sustainability, and regulation. Here's a look at what these rickshaws are, how they work, and the impact they've had.

A rise in battery-powered rickshaws

The rise of battery-powered rickshaws in Bangladesh began in 2007 when the first imports from China started arriving. These vehicles, equipped with electric motors and lead-acid batteries, quickly gained popularity as a cheaper and more efficient alternative to traditional pedal-powered rickshaws. Over time, local workshops began assembling their own versions of these vehicles, using imported motors and locally produced batteries. Today, an estimated four million battery-powered rickshaws and easy bikes ply across Bangladesh, with many of them ruling the streets of Dhaka.

The rapid expansion of the industry has been driven largely by the affordability and convenience of battery-powered rickshaws. For rickshaw drivers, the switch from pedal to battery power has been transformative. Mohammad Aslam, a rickshaw puller in Dhaka's Mirpur area, explained, "I used to pedal for years, but after I switched to a battery rickshaw, life got easier. Now, I can work longer hours without feeling exhausted. But these locally made ones aren't always reliable. The motor sometimes breaks down, and when the battery runs out, I have no choice but to push it back to the garage. Still, it's better than the old days of constant pedalling."

The battery: Powering the ride

The battery is the heart of the electric rickshaw, providing the power needed to drive the motor and propel the vehicle. Most battery-powered rickshaws in Bangladesh are equipped with lead-acid batteries, a tried-and-tested technology that has been widely used in vehicles for decades. These batteries are relatively inexpensive, which makes them a practical choice for the low-cost rickshaws that dominate Bangladesh's streets. However, they come with their own set of limitations.

Lead-acid batteries are heavy, with a typical battery set consisting of four or five 12-volt batteries connected in series to deliver the 48 or 60 volts required to power the motor. These batteries can store enough energy to allow the rickshaw to travel between 80 and 120 kilometres on a single charge, depending on factors such as passenger weight, terrain, and driving speed. Charging the batteries takes between six and ten hours, usually overnight, with garages and drivers often drawing power from the national grid.

Lead-acid batteries remain the dominant power source for battery rickshaws, mainly because of their affordability and widespread availability. The possibility of switching to more advanced battery technologies, such as lithium-ion batteries, remains a distant prospect, as the higher costs make them inaccessible to most drivers.

The motor: Driving the electric rickshaw

The motor is the component that transforms the stored electrical energy from the battery into mechanical energy, propelling the rickshaw forward. Most of the motors used in Bangladesh's battery-powered rickshaws are imported from China, which has been the primary supplier of electric rickshaw technology since their introduction in 2007.

The motor is typically mounted to the rear wheel of the rickshaw and is powered by the battery. These motors come in a range of power ratings, usually between 600W and 1200W. The 600W motors were common in the early days of battery-powered rickshaws, as they provided enough power for the vehicle to move at relatively low speeds—usually around 20 to 25 km/h. However, as demand grew for faster, more powerful vehicles, motors with higher power ratings, such as 800W and 1200W, became more prevalent.

The increased power of these motors allows the rickshaws to reach speeds of up to 40 km/h, but with higher speed comes greater risk. Traditional rickshaw frames and braking systems were never designed to handle these speeds, and many locally assembled rickshaws, in particular, struggle to maintain stability and control at high speeds. The motors are controlled by a throttle on the driver's handlebar, giving the driver full control over acceleration. However, the simplicity of the motor design means that there are often no advanced safety features, such as automatic speed limiting or regenerative braking, which could help manage the risks associated with higher speeds.

The motors themselves are generally reliable, but the combination of a powerful motor with a lightweight, often poorly reinforced frame can lead to mechanical issues. The motors place extra stress on the rear wheel and axle, causing faster wear and tear. Additionally, because the motors are imported and relatively expensive, repairs can be costly. Drivers operating locally assembled rickshaws frequently face breakdowns due to mismatched components and poor assembly quality.

Shahidul Haque, a garage owner in Dhaka's Karwan Bazar, pointed out, "We get the motors and controllers from China, but we build the rest here. The frames are just old pedal rickshaws that we adapt to fit the battery and motor. It's not perfect, but it's cheaper than importing the whole vehicle."

The frame: Adapting an old design for a new purpose

The frame of a battery-powered rickshaw is another area where the limitations of retrofitting become apparent. Most of these vehicles are built on the same basic frame as traditional pedal-powered rickshaws. This frame, made from lightweight steel tubes, was originally designed to carry the relatively low weight of the driver and passengers at slow, manually powered speeds.

When the same frame is used for a battery-powered rickshaw, several challenges arise. First, the addition of a heavy lead-acid battery and a motor significantly increases the overall weight of the vehicle. This extra weight puts additional stress on the frame, which was not built to support the heavier load. Over time, this can lead to structural failures, such as cracked welds, bent axles, and broken support beams, especially when the rickshaw is used on the rough and uneven roads common in many parts of Bangladesh.

Moreover, the original design of the rickshaw frame was never intended to handle the higher speeds enabled by the electric motor. At speeds of 30 to 40 km/h, the lightweight frame can become unstable, especially when turning or manoeuvring through heavy traffic. This lack of stability is one of the key reasons why accidents involving battery-powered rickshaws are relatively common. Abdul Majid, a rickshaw driver, explained, "Sometimes it feels like the whole rickshaw will fall apart. The frame wasn't made for this kind of speed, but it's the only option we have."

To address these issues, some manufacturers have started reinforcing the frames of locally assembled battery-powered rickshaws, adding extra supports to accommodate the weight and stress. However, these modifications are often minimal, and many rickshaws continue to operate with the same fragile frames as their pedal-powered counterparts.

Local vs global

In fully imported rickshaws from China, the frame is typically better suited for electric operation. These vehicles are purpose-built to handle the weight of the battery and motor, as well as the higher speeds they can achieve. However, these imported models are more expensive, making them less accessible to most drivers in Bangladesh, where affordability is a primary concern.  Today, over 100 factories operate in the country, producing batteries and importing motors and other parts from China. Approximately 80% of the market is controlled by Chinese firms, while domestic companies like Navana and Saif Powertec have set up battery production units, albeit on a smaller scale.

A fully imported battery-powered rickshaw from China typically comes equipped with a 48V 1000W motor, drum brakes, and a differential transmission system, allowing it to carry up to five passengers. These vehicles are more reliable and better suited to handle the rigours of city driving than locally assembled models, but they are also more expensive.

The environmental and economic impact

While battery-powered rickshaws offer a cleaner alternative to petrol-powered vehicles, they are not without their environmental drawbacks. The illegal charging of rickshaw batteries has placed a significant strain on the country's electricity grid. It is estimated that the daily charging of these vehicles consumes up to 110 megawatts of electricity per day, with many garages and charging stations tapping into unmetered electricity connections.

Lead-acid batteries are not also easily recyclable, and Bangladesh lacks the infrastructure to safely dispose of or recycle these batteries when they reach the end of their lifecycle. Improper disposal can lead to soil and water contamination, as lead and other harmful chemicals leach into the environment. Despite their affordability, lead-acid batteries also have a relatively short lifespan, typically lasting only a few years before needing replacement, which exacerbates the waste problem.

Government attempts at regulation

The Dhaka Metropolitan Police (DMP) traffic department has recently launched a series of drives against unauthorised battery-powered rickshaws in Dhaka, which have been operating on the city's main roads in violation of traffic rules since August 5. These vehicles, which are often seen on flyovers and busy thoroughfares, have been blamed for exacerbating Dhaka's infamous traffic congestion and posing risks to public safety. Despite the crackdown, no fines were issued, and none of the rickshaws were impounded.

Attempts to regulate the battery-powered rickshaw industry have been fraught with difficulty in the past. In 2021, the government drafted a policy to legalise the use of battery-powered rickshaws and easy bikes, but it has yet to be finalised. As a result, many of these vehicles continue to operate illegally, without registration or proper safety checks. In May 2023, the Awami League government attempted to enforce a ban on battery-powered rickshaws in Dhaka, but the decision was met with widespread protests by drivers who argued that the ban would leave them without a source of income. The government eventually backed down, allowing the vehicles to continue operating in the capital.