GB250+  5250A 12V UltraSafe Lithium Jump Starter

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Start the vehicle within 60 seconds after pressing the power button on Boost. After the 60-second timeout is complete, the unit must be powered off, then back on, to initiate a new jump-start sequence.

We took our UltraSafe technology and made it better— UltraSafe 2.0. It's still our simple, mistake-free design featuring spark-proof technology and reverse polarity protection, but with enhanced thermal efficiency and power management to provide better performance and longer battery life.

With two built-in 2.1A USB ports, you can power multiple devices at the same time, such as smartphones, tablets, action cameras, wireless headphones, wearables and more. With over 242 watt-hours of lithium power, the GB250+ can provide endless hours of operation and recharge your devices multiple times before needing a recharge.

From 0-100% 4X Faster. Charge directly from the vehicle's 12-volt auxiliary port or the XGC4 4-Amp Power Adapter to recharge it’s 242 watt-hours lithium-ion battery in 8.5 hours.

More than a jump starter, Boost MAX is a useful tool for daily use and emergency situations alike. The GB250+ is equipped with a 600-Lumen LED flashlight with various brightness modes, SOS, and emergency strobe— handy to have as a roadside or road trip tool.

Integrated Voltmeter / 60 Second Countdown Timer. The Boost MAX GB250+ is equipped with an integrated voltmeter to help pinpoint battery issues. The voltmeter doubles as a 60-second countdown timer, which shuts off GB250+ after 60 seconds to help preserve internal battery charge.

Technical Specifications

What’s in The Box

  • GB250+ Lithium Battery Jump Starter
  • 56-Watt XGC Power Adapter
  • 12-Volt 2-Foot XGC Cable
  • Protective Carrying Case
  • User Guide & Warranty Information

Starting Current

5250 Amps (Peak)


12 Volt

Battery Types

12 Volt Lead-Acid Battery Systems

Internal Battery

242 Watt-Hour Lithium-Ion

Operating Temperature

-4°F to 122°F (-20°C to +50°C)

Charging Temperature

32°F to 104°F (0°C to +40°C)

Storage Temperature

-20°C to +50°C

USB (Output)

Dual 5 Volts, 2.1 Amps


Natural Convection

12V XGC (Input)

12 Volts, 4 Amp

12V XGC (Output)

12 Volts, 15 Amp

Gas Engine Rating

Up to 16.0 Liters, Safe On All Engine Sizes

Diesel Engine Rating

Up to 16.0 Liters, Safe On All Engine Sizes

LED Worklight


Product Size

Height: 8.62 Inches (218.9 mm)
Width: 12.43 Inches (315.7 mm)
Depth 3.68 Inches (93.5 mm)
Weight: 14.7 lbs (6.67 kg)

IP Rating

IP65 (w/ Ports Closed)

Limited Warranty

1-Year Hassle-Free Warranty