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)



Battery Types

12V 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 5V, 2.1 Amps


Natural Convection

Dimensions (LxWxH)

12.4 x 6.1 x 3.7 in


14.7 lbs

12V XGC (Input)

12V @ 4 Amp

12V XGC (Output)

12V @ 15 Amp

Gas Engine Rating

Up to 16.0 L, Safe On All Engine Sizes

Diesel Engine Rating

Up to 16.0 L, Safe On All Engine Sizes

LED Worklight