leagend JS300 PRO and JS300 PRO-D Coming to Kickstarter October 9 with “One System. Two Ways to Start.”

leagend JS300 PRO and PRO-D launch on Kickstarter October 9, combining battery-free supercapacitor technology, smart monitoring and two ways to start.

LAS VEGAS, NV, UNITED STATES, October 8, 2026 /EINPresswire.com/ -- leagend, an automotive technology brand and a top manufacture in the automotive aftermarket industry with more than 20 years of experience in battery testing, monitoring and vehicle electronics, is preparing to introduce its latest innovations, the JS300 PRO and JS300 PRO-D, on Kickstarter on October 9, 2026.
Built around battery-free supercapacitor technology, permanent vehicle installation and intelligent battery monitoring, the new systems are designed to rethink the traditional portable jump starter—from an emergency device stored in the trunk to an always-ready part of the vehicle's starting system.
The upcoming Kickstarter campaign, “leagend JS300 PRO: One System. Two Ways to Start.”, introduces a new approach to vehicle starting that combines multiple intelligent functions within one permanently installed system.

One System. Two Ways to Start.
The JS300 PRO series is built around a simple concept: one permanently installed system, two ways to start.
Its battery-free supercapacitor system remains connected to the vehicle and is designed to provide starting assistance under different battery conditions. With intelligent starting logic and multiple force-start methods, the system gives drivers greater flexibility when dealing with weak or depleted vehicle batteries.
This approach moves the jump starter beyond the traditional portable device.

Instead of:
Carry → Charge → Store → Wait for an Emergency
the JS300 PRO series is designed around:
Install → Monitor → Stay Ready

Built for Extreme Conditions
The JS300 PRO series is engineered for demanding environments, with an operating temperature range of −40°C to 80°C.
This extreme-temperature capability is particularly relevant for drivers who operate vehicles in harsh winter or hot-weather conditions. Unlike conventional portable jump starters that rely on built-in lithium batteries, the JS300 PRO series uses battery-free supercapacitor technology for its starting-energy storage.
Supercapacitors can rapidly absorb and release energy for high-current applications, making them well suited to vehicle starting assistance.
The battery-free architecture also eliminates the need to periodically recharge a built-in chemical battery simply to keep the jump starter ready.

More Than a Jump Starter: Test, Monitor and Protect
A key difference between JS300 PRO and a traditional jump starter is its ability to continuously monitor the vehicle battery and starting system.
Through the smart app, users can access important battery data, including:
• State of Charge (SoC)
• State of Health (SoH)
• Cold Cranking Amps (CCA)
• Battery voltage
• Starter voltage
• Battery and starter temperature
• Starting performance
• Starting history and trends
By combining battery testing, monitoring and starting assistance in one system, JS300 PRO is designed to help drivers understand their battery condition before a failure occurs.

This creates a broader product concept:
Jump Starter + Battery Tester + Battery Monitor + Battery Protector + Always-Ready Start System.

Self-Learning Mode for Smarter Vehicle Starting
The JS300 PRO series also introduces Self-Learning Mode, allowing the system to learn from vehicle starting and battery behavior.
Rather than functioning as a simple manual high-current power source, the system is designed to use vehicle and battery information to support more intelligent starting assistance.
This helps make the system more adaptive to real-world vehicle conditions while reducing the need for drivers to manually manage the jump-starting process.

Drive Mode Integrates the System with the Vehicle
Another key feature is Drive Mode, which is designed specifically for the permanently installed configuration.
When the vehicle is running, the system works with the vehicle's starting battery and charging system according to its intelligent operating logic. The system can help manage transient starting-related loads while remaining integrated with the vehicle.
When the engine is turned off, the system returns to its appropriate standby condition.
This allows the JS300 PRO series to function not simply as an emergency device, but as an integrated component of the vehicle's starting ecosystem.

Designed to Help Extend Battery Service Life
Because JS300 PRO continuously monitors battery and starting conditions, it can provide drivers with greater awareness of battery performance and degradation.
Its intelligent operating modes are designed to help reduce unnecessary stress on the vehicle's starting battery and support longer battery service life.
Instead of waiting until a battery fails, drivers can use battery health and CCA information to identify potential deterioration earlier and make better-informed maintenance decisions.
For vehicles that experience frequent short trips, long parking periods or demanding starting conditions, this proactive approach can be particularly valuable.

Smart App Keeps Vehicle Data at Your Fingertips
The smart app is another major difference between the JS300 PRO series and conventional jump starters.
Rather than providing only emergency starting power, the app gives users access to vehicle battery and starting-system information through their smartphone.
Users can monitor battery condition, view CCA and SoH data, review starting performance and track historical information.
This turns the jump starter into a connected vehicle-management tool—giving drivers information that would normally require a separate battery tester or diagnostic device.

JS300 PRO-D Adds a Solar-Assisted Onboard Display
The JS300 PRO-D takes the concept one step further with a solar-assisted onboard display.
The display provides at-a-glance access to key information from both the vehicle battery and the supercapacitor system. Drivers can view important information such as SoC directly from the onboard display without opening the mobile app.
The solar-assisted design provides an additional power source for the display, while the smart app provides deeper information and intelligent monitoring capabilities.

Together, the onboard display and app provide two complementary interfaces:
At-a-Glance: key information directly inside the vehicle.
In-Depth: detailed battery and starting data through the smart app.
From Emergency Response to Proactive Vehicle Protection
With JS300 PRO and JS300 PRO-D, leagend is developing a new approach to vehicle starting technology in which starting assistance, battery testing, battery monitoring, intelligent connectivity and proactive battery management work together.
The result is more than a conventional jump starter.
It is a permanently installed system designed to test, monitor, protect and assist the vehicle's starting system—while remaining ready for the moment starting assistance is needed.
“We want to transform emergency response into proactive vehicle protection,” said a leagend representative. “JS300 PRO and JS300 PRO-D combine supercapacitor starting technology with intelligent battery monitoring, connected data and proactive vehicle care in one permanently installed system.”

Coming to Kickstarter October 9
The leagend JS300 PRO Kickstarter campaign will officially launch on October 9, 2026, and is scheduled to run through November 22, 2026.
Under the campaign theme “One System. Two Ways to Start.”, leagend will introduce:
leagend JS300 PRO — A permanently installed, battery-free supercapacitor jump starter featuring intelligent starting assistance, Self-Learning Mode, Drive Mode, battery CCA and SoH monitoring, smart app connectivity and functions designed to help extend vehicle battery service life.
leagend JS300 PRO-D — Adds a solar-assisted onboard display for convenient, at-a-glance monitoring of vehicle battery and supercapacitor system data, while retaining the intelligent starting and smart app functions of the JS300 PRO platform.
The Kickstarter campaign will give drivers, automotive enthusiasts and technology-focused backers the opportunity to discover leagend's new approach to always-ready, battery-free vehicle starting and battery management.

Kickstarter Campaign: leagend JS300 PRO: One System. Two Ways to Start.
Launch Date: October 9, 2026
Campaign Period: October 9 – November 22, 2026
Products: leagend JS300 PRO and JS300 PRO-D

About leagend
With more than 20 years of experience in automotive electronics and as a top manufacture in the automotive aftermarket industry, leagend develops and manufactures battery testers, battery monitors, battery chargers, OBD II diagnostic tools, thermal imaging products and battery-free supercapacitor jump starters.
Driven by strong product development and R&D capabilities, leagend continues to develop practical automotive technologies designed to improve vehicle maintenance, starting reliability and everyday driving confidence.
More about leagend supercapacitor jump starter, please click here for more.
Media & Business Inquiries:
info@leagend.com

Arthur Kingsly
Shenzhen leagend Optoelectronics Co., Ltd.
+86 755 8282 1859
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