Portable Jump Starters Ranked by Power and Size
The NOCO Boost Plus GB40 is the best portable jump starter for most drivers, covering typical petrol engines in a glovebox sized pack. The NOCO Boost Pro GB150 handles large diesels, and the HULKMAN Alpha85 offers the strongest mix of power and display features for the outlay.
For most drivers the NOCO Boost Plus GB40 is the jump starter to keep in the boot, with the HULKMAN Alpha85 as the better value step up and the NOCO Boost Pro GB150 reserved for large diesel engines and heavier vehicles.
Jump starters are hard to compare because peak amp figures are measured differently between brands and say little about sustained cranking. We compared stated engine size limits, battery capacity in amp hours or watt hours, clamp safety features, self discharge behaviour and the usefulness of the extra ports, then weighed what owners report about cold weather performance.
How to choose
Peak amps are not a like for like number Brands measure peak output under different conditions, so a 4000 amp claim from one maker does not necessarily beat a 2000 amp claim from another. The more useful figure is the stated maximum engine size, in litres and by fuel type, because that is the manufacturer committing to a real world limit. Match that to your engine and treat the amp headline as marketing.
Diesel needs far more than petrol Diesel engines have higher compression and need substantially more cranking current, which is why every spec sheet lists separate petrol and diesel limits. A pack rated for a 6 litre petrol engine may only be rated for a 3 litre diesel. If you drive a diesel, size up rather than buying at the edge of the rating, especially if you live somewhere cold.
Cold weather changes everything Lithium packs lose available output as temperature drops, exactly when batteries are most likely to fail. Owners report noticeably weaker performance below freezing, so keeping the unit inside the house or cabin rather than in an unheated boot makes a real difference. Some packs include a warming mode that preconditions the cells before attempting a start.
Check it every few months A jump starter that sits flat in a boot for two years is a paperweight when you need it. Lithium packs self discharge slowly and most makers suggest topping up every three to six months. Put a recurring reminder in your phone, and if the pack has a charge readout rather than simple LEDs it is far easier to see where you stand at a glance.
Our top picks
NOCO Boost Plus GB40
The GB40 is the pack most drivers should own because it covers the engines most people actually drive while staying small enough to live in a glovebox. Spark proof clamps and reverse polarity protection mean a tired driver in the dark is unlikely to cause damage, and the manual override handles a battery too flat for the unit to detect. It holds charge for months between top ups.
Pros
- Genuinely glovebox sized
- Spark proof clamps make it forgiving to use
- Holds charge well over long storage
Cons
- Micro USB charging is slow by current standards
- Not enough for large diesel engines
HULKMAN Alpha85
The Alpha85 pairs a 2000 amp peak output with a clear colour screen that shows charge level and connection status, which removes most of the guesswork at the roadside. It charges over USB-C at a much higher rate than the older micro USB packs, so a flat unit is usable again quickly. Owners report reliable starts on larger petrol engines and mid size diesels in cold conditions.
Pros
- Colour display removes roadside guesswork
- USB-C charging is far faster than micro USB
- Strong cold weather starts reported by owners
Cons
- Bulkier than a glovebox pack
- Clamp cables are shorter than some rivals
NOCO Boost Pro GB150
This is the pack for trucks, vans, boats and large diesel engines where smaller units simply stall out. It uses heavy gauge clamps on long cables that reach awkward battery locations, and the case is built to survive a workshop rather than a glovebox. It is heavy and takes up real space, so buy it because you need the output rather than for the peace of mind.
Pros
- Starts engines other packs cannot touch
- Long heavy cables reach buried batteries
- Rugged case suits workshop and fleet use
Cons
- Heavy and awkward to store in a car
- Overkill for a small petrol commuter
GOOLOO GT4000S
The GT4000S delivers a very high peak output for a pack this size, which gives it headroom on larger diesels without the bulk of a professional unit. It doubles as a sizeable power bank with fast USB-C output, so it earns its space on camping trips as well as in the boot. The clamps include a lit indicator that confirms a correct connection before you crank.
Pros
- Very high output for the size
- Doubles as a capable power bank
- Clamp indicators confirm connection
Cons
- Peak amp claims are hard to compare across brands
- Case is bulkier than its capacity suggests
NOCO Boost X GBX55
The Boost X range is NOCO’s answer to slow charging, with USB-C Power Delivery in and out that refills the pack far faster than the older Boost Plus units. It sits between the GB40 and the big professional packs in output, which covers most petrol engines and mid size diesels. The 400 lumen light is bright enough to actually work by, unlike the token LEDs on cheaper packs.
Pros
- Fast USB-C recharge time
- Bright genuinely useful work light
- Same spark proof clamp design as the GB40
Cons
- Costs noticeably more than the GB40 for modest extra output
- Larger than it looks in photos
DBPOWER 800A Portable Car Jump Starter
A straightforward pack aimed at small and mid size petrol engines, with the basics covered and none of the extras. It includes an LCD showing remaining charge, a compass and a torch with strobe modes, plus USB output for phones. Owners report it handles four cylinder cars reliably, but it should not be relied on for diesel or very cold mornings.
Pros
- Low outlay for a complete kit
- Charge readout is clearer than LED dots
- Light enough to leave in a small car
Cons
- Not rated for diesel engines
- Output drops noticeably in very cold weather
Clore Automotive Jump-N-Carry JNC660
The JNC660 is the old school choice, using a sealed lead acid battery instead of lithium in a case built for daily shop abuse. It delivers strong sustained cranking rather than a brief peak, which is why service departments keep them on the floor. The tradeoff is weight and the need to keep it on charge, so it belongs in a garage rather than a car boot.
Pros
- Strong sustained cranking rather than a short peak
- Built for repeated daily use
- Very long heavy duty cables
Cons
- Heavy and not portable in any real sense
- Needs to stay on charge to stay healthy
How they compare
| # | Model | Peak amps | Best for | Score | Price |
|---|---|---|---|---|---|
| 1 | NOCO Boost Plus GB40 | 1000A | Best overall | 9.4 | Check price |
| 2 | HULKMAN Alpha85 | 2000A | Best value | 9.2 | Check price |
| 3 | NOCO Boost Pro GB150 | 3000A | Best for large engines | 9.0 | Check price |
| 4 | GOOLOO GT4000S | 4000A | Best high output value | 8.8 | Check price |
| 5 | NOCO Boost X GBX55 | 1750A | Best for fast recharging | 8.6 | Check price |
| 6 | DBPOWER 800A Portable Car Jump Starter | 800A | Best budget | 8.3 | Check price |
| 7 | Clore Automotive Jump-N-Carry JNC660 | 1700 peak, 425 cranking | Best for workshop use | 8.0 | Check price |
Common questions
How many amps do I need to jump start my car?
Ignore the amp figure first and check the stated engine limit instead. A pack rated for up to a 6 litre petrol engine, such as the NOCO Boost Plus GB40, covers the vast majority of cars and small SUVs. Larger diesels, vans and trucks need a unit rated specifically for them.
Can a jump starter damage my car’s electronics?
Modern packs include reverse polarity protection and spark proof clamps that refuse to deliver power until they detect a correct connection, which prevents the classic mistakes. Always connect positive first, then negative to an unpainted metal ground point rather than the battery negative terminal where the manual advises it.
How long does a jump starter hold its charge?
Quality lithium packs typically retain a useful charge for several months to a year in storage, though this drops in heat and cold. Manufacturers generally suggest topping up every three to six months. Sealed lead acid units such as the Clore Automotive Jump-N-Carry JNC660 need to stay on charge more or less continuously.
Will a jump starter work on a completely dead battery?
Often yes, using the manual override or boost mode that most packs include for batteries too flat to be detected. Be aware that a battery flat enough to need override may be damaged, so a start is a way to get home rather than a fix.
Can I use a jump starter as a phone power bank?
Most have USB output for exactly that. Just remember that charging devices eats into the reserve you need for a start, so top the pack back up afterwards rather than leaving it half empty in the boot.
How many jump starts can I get from one charge?
Manufacturers commonly quote somewhere between twenty and forty starts from a full charge on a healthy pack, though a single start on a badly discharged battery in cold weather uses far more than one in mild conditions. Treat the quoted figures as a best case.
Is lithium or lead acid better?
Lithium is far lighter and more portable, which is why it dominates consumer packs. Lead acid units deliver stronger sustained cranking and tolerate repeated daily use, which is why workshops still buy them. For a car boot, lithium is the sensible choice.
Can I take a jump starter on a plane?
Lithium jump starters generally exceed the watt hour limits for carry on batteries and are not permitted in checked baggage, so most cannot fly. Check the specific watt hour rating against airline policy before travelling, and expect the answer to be no for anything with real jump starting capability.
The bottom line
The NOCO Boost Plus GB40 remains the right buy for most drivers because it is small enough to actually keep in the car and rated for the engines most people own. Drivers wanting more headroom and a clearer roadside interface should look at the HULKMAN Alpha85, which adds a colour display and much faster USB-C charging. Large diesels, vans and boats need the NOCO Boost Pro GB150 rather than a compact pack pushed to its limits.
