NOCO Boost GB40 Jump Starter Review: Keep It Topped Off
1000 amps of pocket-sized rescue — if you remember to keep it charged.
Owners jump dead cars in one try with this 2.4-lb lithium booster. The catch: it self-discharges in storage, so top it off before you rely on it.
Bottom Line
Kept charged, the GB40 does what buyers want it to: it turns a dead battery into a non-event, in a package that lives in a glove box. Don't treat it as set-and-forget, though — the self-discharge in storage is real and comes up again and again. Check it every month or two and it's easy trunk insurance for most sedans and light trucks.
IT STARTS CARS — WHEN YOU'VE KEPT IT CHARGED
On the core job, the buyer consensus is hard to argue with. Charged and ready, the GB40 fires up stubborn cars on the first try — one owner started a battery so dead the trunk wouldn't open, then did it again the same day. The spark-proof, reverse-polarity clamps take the guesswork out of hookup, and when a battery is too far gone to detect, the manual override still gets it going.
THE TRUNK IS WHERE IT QUIETLY DIES
The pattern you can't ignore is self-discharge. Owner after owner charges it full, drops it in the trunk for a rainy day, and finds it drained months later — sometimes down to a couple of bars after a hot summer, sometimes empty. Lithium chemistry and trunk heat split the blame, but the lesson is the same: this is a top-it-off tool, not a forget-it one. A stray press of the flashlight button through the bag speeds that drain, and there's no lock to stop it.
RIGHT FOR SEDANS, WRONG FOR CRANES
For sedans, light trucks, motorcycles and winter commuters, it's an easy call — compact, quick to recharge, reassuring. Point it at a crane or a big diesel and the 1000-amp ceiling shows. On some hybrids the short cables won't reach a hatch-mounted battery. Know your vehicle, keep it charged, and it earns its trunk space.
