Will this work on my truck, or just small cars?

At 1500A peak output, it handles most gasoline engines and lighter diesel trucks. Larger diesel engines or heavy-duty applications may need more cranking power—check your owner's manual for cold-start amperage requirements.

How long does the battery hold a charge if I'm not using it?

Lithium batteries maintain charge far longer than lead-acid, but the exact hold time depends on storage temperature and conditions. Keep it in a cool, dry place and top it off every few months if sitting unused.

Can I use the USB port while jump-starting a vehicle?

It's best to finish the jump-start and let the engine run for a few minutes before charging a phone or device. The jump-starting draws heavy current, and splitting power could reduce available amperage when you need it most.