NOCO Boost GB40 Review: The Jump Starter Worth Keeping in Your Trunk

A dead battery is one of the most common reasons for a roadside call, and the GB40 solves it without needing a second car or a stranger's cables — just this, in your trunk, charged.

Who it's for

This is for anyone who wants to handle a dead battery alone rather than wait for roadside assistance or flag down a second car — commuters, road-trippers, and anyone with an older battery worth insuring against. It's not sized for larger diesel trucks or commercial vehicles, which need one of NOCO's higher-output GB models instead of the GB40.

What we liked

• 1000A peak output is enough to start most cars, and NOCO makes larger models for trucks and diesels if you need more.
• Spark-proof, reverse-polarity protected clamps make it genuinely safer for someone inexperienced to use correctly.
• Doubles as a USB power bank and flashlight, useful beyond just dead batteries.

What could be better

• Needs to be recharged periodically even when unused — it will self-discharge over months sitting in a trunk.
• Not rated for larger diesel engines; check NOCO's bigger GB models if you drive one.

Key specs, explained

• 1,000A peak output is enough cranking power for most gas-engine cars, SUVs, and smaller trucks — but it's a peak figure, not sustained output, so it's meant for the few seconds it takes to turn an engine over, not running accessories for an extended time.
• Lithium battery means it holds a charge far longer in storage than older lead-acid jump packs, but it still self-discharges gradually over months, so a periodic top-up charge (every few months) keeps it ready.
• Spark-proof, reverse-polarity-protected clamps are a genuine safety feature, not just marketing — they prevent the sparking and short-circuit risk that makes traditional jumper cables intimidating for inexperienced users.

Frequently asked questions

Q: How often do I need to recharge it if I never use it? Every few months is a safe habit — lithium jump starters self-discharge slowly over time, and NOCO recommends topping off periodically even with no use.

Q: Will this start a diesel truck? Not reliably — the GB40's 1,000A peak output is sized for gas engines and smaller vehicles; NOCO sells larger GB-series models specifically rated for diesel and bigger engines.

Q: Is it actually safe for someone who's never jump-started a car before? Yes, more so than traditional cables — the spark-proof, reverse-polarity protected clamps are specifically designed to prevent the mistakes (wrong terminal order, accidental sparking) that make cables risky for beginners.

Should you buy it?

For the price of one tow truck call, this earns its spot in a trunk or garage — it's one of the rare car gadgets that's genuinely useful the one time you actually need it.

Check price on Amazon