A portable lithium jump starter for 12-volt batteries in Boats.

NOCO Boost X GBX155 4250A UltraSafe Marine engine Jump Starter.

An all-new design with extreme jump starting power for powerful engines starts. Rated at 4250-amps,
this portable lithium car battery jump starter releases maximum energy at every start.
This isn't an upgrade. It's a whole new series - the Extreme Series
Turbo Chargeable - Boost X is equipped with USB-C technology that, combined with power delivery, gives you lightning-fast recharges.
Completely recharges in just 2.7-hours, or go from 0% to jump starting in just 5-minutes of charge
Charge Everything - With USB-C Power Delivery, you have the power to charge almost everything.
Its internal power bank provides 60-watts of power - both in and out - to effortlessly power your favorite USB-C devices,
like phones, tablets, laptops, wearables, and more
UltraSafe 2.0 - We took our UltraSafe technology and made it better.
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
Maximum Versatility - Boost X is one of the most versatile lithium jump starters ever. Jump start all vehicle types,
including cars, motorcycles, trucks, ATVs, boats, RVs, vans, SUVs, tractors, and more for up to 10.0-liter petrol and 8.0-liter diesel engines
Here's What You Get With Boost X - GBX155 UltraSafe Portable Lithium Car Battery Booster Jump Starter Pack and Power Bank with 60W USB-C Power Delivery,
Heavy-Duty Jumper Cable Clamps, USB-C Charging Cable, 12V USB-C Fast Charger, Microfiber Storage Bag, 1-Year Warranty, and Designed in the USA.

It really does the job!! We started twin Volvo Penta D6's with it. Brilliant.