Battery-free ebike is powered by quick-boosting supercapacitor

Pi-Pop Third-gen Supercapacitor eBike
The third-generation Pi-Pop supercapacitor ebike is now in production. Images courtesy Pi-Pop

In the evolving landscape of sustainable urban commuting, the French-designed Pi-Pop ebike has emerged as a noteworthy entrant, especially in its approach to electric assistance. At first glance, it might appear as just another player in the urban ebike-sharing arena, but its underlying technology tells a different story. The Pi-Pop ebike distinguishes itself by eschewing the traditional battery pack, typical of most ebikes, in favor of a supercapacitor-based system.

The supercapacitor system

Pi-Pop’s journey towards a cleaner, more sustainable mode of urban commuting has led to the development of three generations of battery-free supercapacitor ebikes over the past two years. The latest generation, launched in mid-2023, builds upon its predecessors with several evolutionary enhancements. These include a torque sensor, a suspension fork, and an updated component set, offering an improved riding experience.

Unlike conventional ebikes that rely on a battery pack charged through electrical grids, the Pi-Pop ebike’s power management is both rapid and dynamic. The system harnesses energy from rider pedaling and regenerative braking, converting it into electricity that’s stored in supercapacitors located alongside the rear rack. This design minimizes the impact on flat surfaces, ensuring that the rider doesn’t experience significantly harder pedaling. The energy generation intensifies during downhill coasting and reaches its peak during active braking.

Once the rider begins an uphill journey, the stored electricity is instantly discharged, providing up to 250 watts of electric pedal assistance. This process is seamlessly managed by sensors, balancing charge and discharge across varying terrains.

Pi-Pop Third-gen Supercapacitor eBike How it Works
The Pi-Pop’s supercapacitor continuously charges and discharges during the ride, unlike a battery that depletes after a set distance.

Design and weight considerations

The Pi-Pop ebike does not particularly emphasize weight reduction as a primary advantage of its supercapacitor system. Weighing in at 48 lbs (21.7 kg), it doesn’t claim to be the lightest ebike on the market. The design of the supercapacitor boxes also doesn’t offer a noticeable aesthetic improvement over traditional battery packs.

Pi-Pop Third-gen eBike Supercapacitor Box
Supercapacitor boxes may not be lighter or smaller than a typical ebike battery, but they offer different benefits.

Environmental and practical benefits

Pi-Pop highlights the environmental benefits of their design, noting the use of more basic materials like aluminum, carbon, cellulose, and polymer instead of the sensitive materials required for lithium batteries. This choice not only reduces dependency on these materials but also enhances the lifespan of the supercapacitors, estimated to be between 10 to 15 years. Furthermore, much of the material is recyclable, aligning with sustainable practices.

A unique advantage of this system is its independence from the grid. The battery-free supercapacitor ebike is always ready for a ride, charging its motor power during the ride itself. Although the supercapacitors may drain over a period of around two months when not in use, the bike can be quickly recharged with a few laps, especially if facing uphill routes initially.

Pi-Pop Third-gen Supercapacitor eBike Internal Wires
Pi-Pop integrates wires from its supercapacitors internally, running them through the bike’s frame.

Limitations and market focus

Despite its innovative approach, the Pi-Pop ebike has its limitations. The supercapacitors can store only small amounts of energy, meaning they are not suited for long or steep climbs exceeding a 10% grade over approximately 1,640 feet (500 meters). Beyond this point, the bike’s power gradually reduces, leaving the rider with a heavy, non-electric bike to manage. As a result, Pi-Pop markets this ebike primarily to urban riders dealing with moderate hills, rather than those seeking to navigate challenging terrains like the French Alps.

Pi-Pop Third-gen Supercapacitor eBike Handlebar
Handlebar of the Pi-Pop gen-3 ebike.

Production and pricing

According to Euronews, Pi-Pop currently assembles around 100 bikes per month at its headquarters in Orléans, France. Plans are underway to increase production tenfold in 2024, with an eye towards greater expansion across Europe. The third-generation Pi-Pop battery-free supercapacitor ebike is priced at €2,450 (approximately US$2,680), inclusive of VAT.

Pi-Pop Third-gen Supercapacitor eBike Colorful Display
Colorful display shows power and speed.

Source: Pi-Pop