NOCO GB40 vs GOOLOO GP4000: which jump starter should you carry?

We compiled this from the makers' published specs, the Amazon.co.uk listings and owner reviews. We have not tested either jump starter. Where a spec is missing from the pages we checked, it is left out of the table rather than guessed.

Specs side by side

The differences that matter

Engine rating, not peak amps

The 4000A against 1000A headline looks like a landslide, but peak amps is not measured to one shared standard. The rated engine size tells you more. Both units cover the engines in most UK cars: a 1.0-litre petrol Polo or Fiesta, a 2.0-litre diesel Golf or Transit Custom. The gap only opens above 3.0 litres of diesel, where the GB40 runs out of rating and the GP4000 carries on to 10.0 litres. That is large pickup, big SUV and light commercial territory.

Starts per charge

GOOLOO claims 60 or more starts per charge against NOCO's figure of up to 20 for the GB40. If you keep the unit topped up, 20 is plenty for one car. The higher figure matters if you lend it out, help neighbours on a frosty morning or forget to recharge it for months.

Ports and recharging

The GP4000 has more going on: two USB outputs, a USB-C port that works both ways, and a cigarette lighter adapter in the box so it can recharge from the car's 12V socket on a long drive. The GB40 keeps things simple with USB-C charging and a power bank function. If the jump starter doubles as your phone power bank on camping trips, the GP4000's extra outputs are useful.

Build and warranty

NOCO lists an IP65-rated housing for the GB40. We did not find an IP rating on the GP4000 pages we checked. On warranty, the UK Amazon listing for the GP4000 includes 18 months against 1 year on the GB40 listing. GOOLOO's own US page advertises up to 30 months, which may depend on region or registration, so check the terms that apply to your UK purchase.

Pick the NOCO GB40 if...

• Your car is petrol or a diesel of 3.0 litres or less.
• You want a compact unit with a stated IP65 housing.
• You prefer the simpler USB-C-only setup.

Pick the GOOLOO GP4000 if...

• You drive a diesel above 3.0 litres, or a van or pickup.
• You want the higher claimed starts per charge.
• You want to recharge it from the car and charge two or three devices from it.
• The longer warranty on the UK listing matters to you.

If engine size points you to something bigger from NOCO, seeNOCO GB40 vs GB70. OurGB40 review andGP4000 review go into each unit in more depth. For the bigger picture, read theemergency kit essentials guide,jump starter vs jump leadsand our emergency kit picks.

Frequently asked questions

Is 4000A really four times better than 1000A?

No. Peak amps is a headline figure and makers do not all measure it the same way. The more useful number is the rated engine size: the GB40 is rated for diesels up to 3.0 litres and the GP4000 for diesels up to 10.0 litres. If your engine is inside both ratings, the extra peak current buys headroom, not a different result.

Which one gives more jump starts per charge?

On the makers' figures, the GP4000. GOOLOO claims 60 or more jump starts per full charge, while NOCO lists the GB40 at up to 20. Both figures depend on engine size, temperature and battery condition.

Can I charge the GOOLOO GP4000 in the car?

Yes. GOOLOO says it recharges in about 5 hours either over USB-C from a wall charger, which is not included, or from a car's 12V socket using the supplied cigarette lighter adapter. The GB40 recharges over USB-C, listed at 3 hours.

Why did the GP4000 stop working after several attempts?

GOOLOO describes an over-start protection on the smart cable that activates after more than 4 starts within 2 minutes. It is a cool-down, not a fault. Wait, then try again, and check the clamps and battery terminals between attempts.