NOCO Boost Plus GB40 UltraSafe Lithium Jump Starter
- Best for:
- Glovebox-sized emergency jump-starter for small-to-medium gasoline and diesel vehicles, roadside backup for everyday drivers, car-camping and short road trips where portability matters
- Skip it if you want:
- Heavy-duty fleet or professional use, very large V8/diesel trucks, repeated multi-jump scenarios without recharging, extreme deep-freeze conditions
Main tradeoff: Limited battery capacity — typically only one to two jumps per full charge
Before you buy
Why it works
- Ultra-compact, lightweight, and highly portable — easy to store in a glovebox or under a seatPublished reviews
- Rugged build quality with heavy-gauge clamps and solid polymer housingSmartZone, The Drive, Northern Tool
- Reliable starting power for small-to-mid-size engines (rated to ~6.0L gas / 3.0L diesel)TechGearLab, The Drive, Jumpstarter.io
- Built-in safety features (spark-proof clamps, reverse-polarity protection) and extra utility (USB power output, LED flashlight)Car, Driver, Amazon
Tradeoffs
- Limited battery capacity — typically only one to two jumps per full chargeTechGearLab
- Short, stiff clamps and relatively short leads that can be hard to squeeze or awkward with glovesCar, Driver
- No bundled AC or 12V charger and only a thin carry pouch includedTechGearLab
- Slow charging via micro-USB and limited power-bank capability (single USB-A port)TechGearLab
Details
About the NOCO Boost Plus GB40 UltraSafe Lithium Jump Starter
The most thoroughly tested compact jump starter in its class — top pick at TechGearLab, CNN Underscored, and one of three finalists in a 19-unit head-to-head comparison. It reliably starts gas engines up to 6.0L (and diesel to 3.0L), with verified cold-weather performance including three consecutive starts of a drained 4.0L V6 at 33°F. Glovebox-sized insurance for group car-camping trips; recharge it every six months in storage to keep the pack healthy — a self-discharged lithium cell is the primary failure mode. For the largest V8s in deep cold, the GB50 or GB1000 provides additional cranking margin.
Specifications
- Weight
- 2.4 lb (38 oz)
- Packed size
- 6.4 x 2.3 x 9.4 inches (approx.)
- Materials
- Hard polymer (plastic) shell with rubberized end caps; heavy-gauge steel clamps with molded insulated handles
- Changes from the last model
- Minor cosmetic/accessory tweaks reported; newer runs reportedly moved from micro-USB to USB-C charging on some SKUs
Questions (7)
- Is it worth the price over cheaper alternatives?
- For frequent drivers who value a compact, well-built unit with proven reliability, the GB40's combination of build quality, safety features, and portability justifies the price; budget buyers who need far higher capacity or extra features may prefer larger, feature-rich rivals.
- How many jump starts can I expect per charge?
- Expect roughly one to two jump starts per full charge in typical conditions; reviewers and lab tests consistently report limited usable Wh (around ~15–16 Wh usable) compared with larger packs.
- What size engines will it start?
- NOCO rates the GB40 for up to about 6.0L gasoline and 3.0L diesel engines; reviewers confirm reliable starts for most 4- and 6-cylinder cars but note it can struggle with the largest V8s and heavy diesel engines.
- Can I use it in cold weather?
- Yes for routine emergency use near freezing — reviewers achieved cold starts around ~32°F — but expect reduced capacity in deep-freeze; for sustained cold or repeated cold-weather jumps consider a higher-capacity or more climate-hardened model.
- What charging accessories are included?
- The GB40 ships with a micro-USB charging cable and a thin nylon pouch; it does not include a wall AC or 12V car charger, so those must be sourced separately if desired.
- How should I maintain it while stored?
- Top off the charge every 3–6 months, store at moderate room temperature away from direct sun/heat, and keep clamps dry and free of corrosion to preserve long-term battery health.
- What's included in the box?
- Included are the GB40 unit with attached boost cable assembly (approx. 23" boost cables, 8 AWG), a micro-USB charging cable, and a thin carry pouch; no AC or 12V charger is included.
Care and warranty
Care
- store dry and at moderate temperatures
- top off charge every 3–6 months
- dry and inspect clamps after wet use and clean corrosion if present
- replace charging cable or use recommended USB-C wall adapter for faster charging where applicable
What tends to wear out
- battery self-discharge if left uncharged
- long-term capacity fade and occasional reports of battery swelling after years
Durability
- many users report years of trouble-free service; a minority report eventual battery degradation or swelling after multi-year use
Warranty
Manufacturer lists a 1-year limited warranty; most users report adequate warranty support but some return-to-retailer cases are noted
Sources
“This rugged, compact model delivers solid, trustworthy performance... great for small-to-medium cars and pickups”
“The Noco GB40 is the smallest jump starter in our test with decent power and an easy interface; we wouldn't recommend banking on more than one or two jumps per charge”
“Reliable, consistent — not soon to let you down; heavy-duty cables and reverse-polarity protection stand out”
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Last updated June 25, 2026
