leagend JS300 PRO: A Jump Starter Like Never Before, Now on Kickstarter

What if a jump starter could do more than rescue a vehicle with a dead battery? What if it could stay installed, monitor battery health, prepare for unexpected starting problems, and help drivers reduce the risk of being stranded before an emergency occurs?

With its JS300 PRO series now successfully funded on Kickstarter, leagend is bringing this vision closer to reality. Moving beyond the traditional concept of a portable jump starter, the JS300 PRO reimagines how drivers interact with vehicle starting systems by combining battery-free supercapacitor technology, intelligent battery monitoring, and an always-ready starting solution in one integrated system.

Rather than asking drivers to carry, store, charge, and retrieve a jump starter when trouble strikes, leagend proposes a fundamentally different experience: a jump starter designed to stay with the vehicle and be ready when needed.

Beyond the Traditional Jump Starter
Conventional portable jump starters typically rely on built-in lithium batteries. They offer a convenient emergency solution, but drivers must remember to keep them charged, store them properly, and locate them when a vehicle refuses to start. Over time, an overlooked charging routine can undermine their readiness precisely when they are needed most.

The leagend JS300 PRO takes a different route.
Powered by supercapacitor technology, the JS300 PRO operates without a built-in chemical battery. Its design supports permanent installation on the vehicle, eliminating the need to retrieve a portable device or maintain a separate jump starter battery. By drawing on the vehicle's starting battery to charge its supercapacitors, the system is designed to prepare for starting assistance without the conventional storage-and-recharging routine.

This is more than a change in power technology. It represents a shift from an emergency accessory that drivers keep in the trunk to an integrated starting system that remains connected to the vehicle.
One System. Multiple Layers of Vehicle Protection.

The JS300 PRO is designed to go beyond emergency starting, bringing several useful functions together in one solution.

• Battery-free supercapacitor jump starting: Delivers starting assistance without a built-in lithium battery, with technology designed to perform across demanding temperature conditions.
• Intelligent battery monitoring: Helps drivers understand vehicle battery condition and identify potential starting concerns before they become unexpected disruptions.
• Battery protection and management: Provides additional insight into battery performance and supports a more proactive approach to vehicle battery care.
• Smart app connectivity: Gives users access to relevant system and battery information, bringing greater visibility to the vehicle's starting system.
• Permanent installation: Keeps the system connected to the vehicle, reducing dependence on portable equipment and manual preparation.

By integrating these capabilities, leagend aims to transform the jump starter from a single-purpose emergency tool into a more comprehensive vehicle starting and battery management solution.

Intelligence That Works Before an Emergency
One of the defining ideas behind the JS300 PRO is its focus on preparedness.
Traditional jump starters are generally used after a starting problem has already occurred. The JS300 PRO is designed to take a more proactive approach, using intelligent monitoring and self-learning capabilities to help the system adapt to vehicle starting conditions.

Its Drive Mode further supports the system's intelligent operating approach, while smart app connectivity allows users to access starting-system and battery information. Together, these features are intended to help drivers better understand their vehicles and reduce the uncertainty surrounding unexpected starting problems.

For daily commuters, long-distance drivers, outdoor enthusiasts, and vehicle owners who depend on reliable transportation, this approach offers a different way to think about starting assistance: not simply as a response to failure, but as part of ongoing vehicle care.

Designed for Conditions That Challenge Conventional Solutions
Temperature extremes remain a major challenge for vehicle batteries and emergency starting equipment. The JS300 PRO's supercapacitor-based design is developed for operation in demanding environments, with a stated operating temperature range of -40°C to 80°C.

For drivers facing severe winters, fluctuating temperatures, or demanding outdoor conditions, this capability is an important part of the product's value proposition. Combined with permanent installation and intelligent system monitoring, it offers an alternative to relying exclusively on a portable jump starter that must be maintained separately.

The result is a solution designed around readiness, convenience, and the realities of everyday vehicle ownership.

JS300 PRO: A New Direction for Vehicle Starting Technology
The JS300 PRO is not simply an attempt to make a conventional jump starter smaller, more powerful, or easier to carry. Its core proposition is to rethink the role a jump starter can play in a vehicle.
By bringing supercapacitor technology, intelligent monitoring, and permanent installation together, leagend is exploring a model in which starting assistance becomes a more integrated part of the driving experience.

The JS300 PRO series also includes the JS300 PRO-D, which adds an onboard display with solar-assistance capability to provide users with additional visibility into vehicle battery and supercapacitor system information. This gives customers another way to access essential information while preserving the series' broader focus on intelligent starting support.

With the Kickstarter campaign successfully funded, the project has demonstrated meaningful interest in this alternative approach to jump-starting technology. For leagend, it also represents an opportunity to introduce a different product concept to drivers and automotive technology enthusiasts worldwide.

Discover a Jump Starter Like Never Before
As vehicle technology evolves, the tools drivers rely on must evolve as well. The leagend JS300 PRO challenges the traditional idea that a jump starter should remain unused in a storage compartment until an emergency occurs.

Instead, it brings together battery-free supercapacitor technology, intelligent monitoring, and an always-ready design built around permanent vehicle installation.

For drivers looking beyond conventional emergency equipment, the JS300 PRO offers a new perspective on what a jump starter can be.

Explore the leagend JS300 PRO Kickstarter project and discover a different approach to vehicle starting.

About leagend
leagend develops automotive battery testers, battery monitors, battery chargers, OBD II diagnostic tools, and battery-free supercapacitor jump starters. With more than 20 years of industry experience, the company focuses on product development and practical automotive solutions for drivers, professionals, and business partners worldwide.

Business Inquiries: marketing@leagend.com