How we researched this guide
We compared twelve portable jump starters in and around this mid-budget tier, then ranked six that cover the field honestly: two NOCO lithium units, a cold-weather Hulkman, two high-output GOOLOO units and one lead-acid shop box. Every pick comes from the verified pool behind our pillar guide or its head-to-head research — for each one we read the maker spec sheet or manual and the Amazon item details, and checked the ASIN on the listing itself. No fresh model was added for this tier without a verified record behind it.
Owner evidence came from Bogleheads, IH8MUD, the JL Wrangler Forums, AR15.com, BobIsTheOilGuy, AutoGuide, TractorByNet and Yesterdays Tractors, paraphrased and linked in each block, including the negative reports. We do not test jump starters. Engine ratings are maker ratings, written as rated to, and listing figures that conflict are printed as conflicts. This guide sits between our pillar guide to portable jump starters and the budget guide, in the portable jump starters category; head-to-heads live in jump starter comparisons, starting with NOCO vs GOOLOO.
The 30-second answer
Most drivers in this tier should buy the NOCO Boost Plus GB40: rated to 6.0L gas and 3.0L diesel at 2.4 lb. Want fast USB-C charging? The NOCO Boost X GBX45. Cold winters and a display? The Hulkman Alpha 85S. The largest gas or diesel ratings here? The GOOLOO GT4000S. The same diesel reach for value money? The GOOLOO GP4000. Starting vehicles all day in a shop? The lead-acid Clore Jump-N-Carry JNC660 — reserve over portability.
Best Overall
NOCO Boost Plus GB40
The compact benchmark at the heart of this tier: 1,000A, rated to 6.0L gas and 3.0L diesel, at 2.4 lb with spark-proof, reverse-polarity protection. Best if one car or SUV is the job and the pack will live in a glovebox.
Fastest Recharge
NOCO Boost X GBX45
The USB-C pick: 1,250A, rated to 6.5L gas and 4.0L diesel, with 60W Power Delivery in and out and a maker-stated 48-minute full recharge. Best if a flat pack is as bad as a flat battery.
Best for Cold Weather
Hulkman Alpha 85S
The winter pick: 2,000A, rated to 8.5L gas and 6.0L diesel, pre-heat technology, a -40F working-temperature rating and a smart display. Best if starts happen in real cold and you want the pack to report its own state.
Strongest Litre Ratings
GOOLOO GT4000S
The output pick: 4,000A peak, rated to 12.0L gas and 10.0L diesel, 100W two-way USB-C and a status screen. Best if your engine is past every other lithium rating in this tier.
Best Value Power
GOOLOO GP4000
The value power pick: 4,000A, rated for all gas engines and diesels to 10.0L, with a DC outlet and an included EVA case. Best if rating coverage per unit of money matters more than a screen or fast USB-C.
Best Lead-Acid Shop Box
Clore Jump-N-Carry JNC660
The reserve pick: a 22Ah lead-acid AGM box with 1,700 peak amps, long #2 AWG cables and a built-in automatic charger. Best if you start many vehicles, often, and weight does not matter.
| Jump starter | Peak amps | Maker engine rating | Recharge / output | Warranty | Check Price |
|---|---|---|---|---|---|
| NOCO Boost Plus GB40 | 1,000A | 6.0L gas / 3.0L diesel | Micro-USB in; USB out 5V/2.1A | 1 year | |
| NOCO Boost X GBX45 | 1,250A | 6.5L gas / 4.0L diesel | 60W USB-C PD in/out | 1 year | |
| Hulkman Alpha 85S | 2,000A | 8.5L gas / 6.0L diesel | 65W speed charge in; USB-C PD18W out | 2 years (maker-stated) | |
| GOOLOO GT4000S | 4,000A | 12.0L gas / 10.0L diesel | 100W USB-C PD in/out | 18 months | |
| GOOLOO GP4000 | 4,000A | All gas / 10.0L diesel | USB-C in/out; DC 15V/10A out | 18 months | |
| Clore Jump-N-Carry JNC660 | 1,700A (425 cranking) | All vehicles, light commercial (no litre rating published) | Built-in automatic AC charger | 1 year |
Jump starter size calculator
Choose your fuel and enter your engine size in litres. We match it only against the maker litre ratings of the six picks in this guide, and recommend the smallest pick whose rating covers your engine. The lead-acid Clore box carries no maker litre rating, so it is never a calculator answer — it is the repeated-starts alternative in the text.
Not sure of your engine size? The vehicle table below lists typical engines by class. If the same battery keeps dying, a pack in any tier is not the fix — read why batteries drain and our battery guide before spending on a bigger unit.
How to choose a jump starter in this tier
This tier is where jump starters stop being glovebox novelties and start offering real choices: fast USB-C refills, cold-weather technology, status screens and diesel ratings that reach heavy trucks. The sizing rule does not change with the budget. Peak amps are still the least comparable number on any box — buy by the maker litre rating for your fuel, then spend the rest of the tier on the feature your mornings actually need.
Peak amps vs engine size
Peak current is a brief maximum measured differently by every brand, which is why two 4,000A GOOLOO units here carry different engine coverage on paper. The more honest numbers are the maker litre rating and any published starting or cranking figure — the GT4000S publishes 800A for three seconds, the Clore 425 cranking amps. Compare ratings first, headlines last, and keep headroom if your engine is old, cold or hard-starting.
Gas vs diesel ratings — always the lower number rules
Diesels crank harder, so every dual-rated pick here carries a diesel figure well below its gas figure — the GB40 drops from 6.0L gas to 3.0L diesel, the Hulkman from 8.5L to 6.0L. If you drive a diesel, size only from the diesel column. In this tier that column is generous: it runs to 10.0L on both GOOLOO units, which is why the calculator can honestly cover heavy-duty diesels without leaving the guide.
What this tier buys over the budget class
Stepping up from the budget class buys refill speed (60W and 100W USB-C Power Delivery), information (the Hulkman and GT4000S displays), cold technology (Hulkman pre-heat), and diesel reach. It does not buy permission to ignore protections or storage discipline. The budget field itself is ranked in our budget jump starter guide — several of its picks are the right answer for small cars at lower cost.
Recharging speed and USB-C PD
A pack that takes all night to refill gets left flat. The GBX45 refills in a maker-stated 48 minutes on 60W USB-C PD and the GT4000S in about 1.2 hours on 100W, while the GB40 still uses slow Micro-USB and the GP4000 USB-C input is a modest 15W on the maker chart. PD output matters too if the pack doubles as laptop power — the Hulkman PD18W output will not do that job like 60W or 100W will.
Safety protections — reverse polarity and spark-proof
The mistake these packs must forgive is a rushed connection in the dark with cold hands. The NOCO pair publish spark-proof, reverse-polarity protection, the Hulkman publishes a ten-protection list, and the GOOLOO units publish protection lists including overcharge and short-circuit. Manual override and force modes bypass detection for fully flat batteries — a last step, never a first one, on any pick in any tier.
Cold-weather performance and storage
Cold cuts lithium output while engines crank hardest. Working ratings here run from -20C on the NOCO packs to a -40F rating with pre-heat on the Hulkman 85S, and the lead-acid Clore simply carries reserve instead of electronics. Storage matters as much: keep any pack charged, check it on a calendar rather than after a failure, and never charge a lithium pack outside its published charging range.
Typical engine sizes by vehicle class
Typical factory engines, as sizing examples — check your own engine code before buying. The pick column applies the maker ratings above, the same logic as the calculator.
| Vehicle class | Typical engines | Sizing guidance | Pick that covers it |
|---|---|---|---|
| Compact and midsize cars | 1.5–2.5L gas | Well inside the smallest rating in this tier | NOCO GB40 |
| Full-size cars and crossovers | 2.0L turbo to 3.6L gas | GB40 territory; USB-C buyers step to the GBX45 | NOCO GB40 / GBX45 |
| Half-ton pickups, gas | 5.3L, 5.7L and 6.2L V8 gas | Inside GBX45 and Hulkman gas ratings | Hulkman Alpha 85S |
| Half-ton pickups, diesel | 3.0L diesel | Exactly at the GB40 diesel ceiling — buy headroom instead | NOCO GBX45 |
| Heavy-duty pickups, diesel | 6.6L and 6.7L diesel | Past the Hulkman diesel rating; inside both GOOLOO ratings | GOOLOO GT4000S / GP4000 |
| Large diesels and equipment | Diesel above 7.0L, to 10.0L | Only the GOOLOO diesel ratings reach this band | GOOLOO GT4000S |
| Shops and fleets, mixed | Mixed gas and diesel, many starts a day | Reserve and cable reach beat litre ratings | Clore JNC660 |
Truck owners sizing other 12V gear will recognise the discipline: rate for the real load, not the badge — the same rule behind what size winch do I need and diesel truck winch picks.
Jump starters by tier position
| Tier position | What you get | Example pick |
|---|---|---|
| Core of the tier | The proven compact benchmark with override and the deepest owner record | NOCO GB40 |
| Core, fast charge | More rating headroom plus 60W USB-C PD in and out and a sub-hour refill | NOCO GBX45 |
| Upper, cold and display | Pre-heat for extreme cold, a smart display and 65W speed charging | Hulkman Alpha 85S |
| Upper, output | The strongest numbered litre ratings, 100W two-way charging and a screen | GOOLOO GT4000S |
| Value power | The same 10.0L diesel reach without the screen or 100W charging | GOOLOO GP4000 |
| Shop position | Lead-acid reserve, long heavy cables and a built-in charger — bought for duty | Clore JNC660 |
Every position above sits inside the tier intent of this guide at research time; street pricing in this class moves with promotions, so confirm the listing still sits in tier before buying — the fineprint under each pick says the same. The full field, including the upper-tier lithium flagship excluded here as above class, is ranked in our pillar guide.
Types of portable jump starter
| Type | Pros | Cons | Best for |
|---|---|---|---|
| Compact lithium | Lightest and smallest; holds charge in a glovebox; doubles as a phone power bank | Smallest energy reserve; slowest charging on the GB40; diesel ratings are modest | One car or SUV — GB40, GBX45 |
| High-output lithium | Ratings for large V8s and diesels; fast USB-C PD; displays on two models here | Bigger than compact packs; headline peak amps still not comparable across brands | Trucks, diesels, mixed households — Hulkman, GT4000S, GP4000 |
| Lead-acid jump box | Large reserve for repeated starts; long, heavy cables; simple, repairable battery | Heavy; battery needs periodic charging and eventual replacement; few modern ports | Shops, fleets, farms — JNC660 |
| Inflator-combo | One box jumps and inflates | No pick in this guide is a true inflator-combo: the GOOLOO and Clore DC outlets power a separate inflator instead, which keeps each tool replaceable | Drivers who value one-box storage over tool quality — not ranked here |
If portable power for other gear is part of the brief, compare the approach in portable winches, portable 12V winches and portable winches for trucks — different tools, same reserve-versus-weight trade.
Detailed reviews: the six picks in full
Each pick is checked the same way: why it earns its place, what the maker publishes, who it fits, what owners report — good and bad — and who should walk past it. Conflicts found in maker or listing figures are printed, not smoothed over.
Best Overall: NOCO Boost Plus GB40
Best Overall — the compact pack most drivers in this tier actually need
Why the NOCO GB40 is our pick
The GB40 wins on fit, not force. Most dead-battery mornings involve a mainstream gas engine, a battery that is flat rather than destroyed, and a driver who wants the pack back in the glovebox afterwards. A 1,000A pack rated to 6.0L gas, at 2.4 lb, with NOCO spark-proof and reverse-polarity protection, is exactly that shape — and its long production run means its weaknesses are known, not hidden.
NOCO GB40 key specs
- Part number: GB40
- Peak current: 1,000A
- Maker engine rating: Gas up to 6.0L; diesel up to 3.0L
- Starts per charge: Up to 20 (maker)
- Internal battery: Lithium-ion (Wh not published in the manual checked)
- Charging input: Micro-USB, 5V/2.1A
- USB output: 5V, 2.1A
- Safety: Spark-proof connections; reverse-polarity protection; manual override for very low batteries
- Housing: IP65 (ports closed)
- Operating temperature: -20C to +50C; charging 0C to +40C
- Light: 100-lumen LED, 7 modes
- Weight: 2.4 lb
- Warranty: 1-year limited
NOCO GB40: fits and best for
Cars, crossovers and SUVs with gas engines to 6.0L, small diesels to 3.0L, motorcycles and mowers. It is the glovebox pick for a single-vehicle household, a teen driver, or a second car — anywhere the job is occasional starts, not daily duty. In this tier it is also the value anchor: everything above it in this guide buys a feature, not basic competence.
NOCO GB40 pros and watch-outs
Pros
- Small and light enough to live in the car permanently
- Spark-proof, reverse-polarity protection suits first-time users
- Manual override exists for batteries too flat to detect
- Long production run — behaviour and limits are well documented
- IP65 housing with ports closed
Watch-outs
- Micro-USB charging is slow and dated next to the USB-C PD picks
- Diesel rating stops at 3.0L — most diesel trucks need a bigger pick
- Small pack energy: phone charging drains jump reserve quickly
- No display — LEDs are the whole fuel gauge
NOCO GB40: what owners report
On Bogleheads, an owner reports using a GB40 over a dozen times without a failure, praising the sturdy clamps and the override that lets it deliver a jump when a battery shows almost no detectable voltage; several owners in the same discussion say they keep one in each family car.
Balance comes from IH8MUD, where an owner reports a GB40 failing to crank a totally flat large SUV and prefers a larger unit for overhead in adverse conditions. Both reports are consistent with the rating: inside 6.0L gas it is dependable; at the edge, buy headroom.
NOCO GB40: who should not buy
Diesel truck owners above 3.0L should not buy this pack — it is below the maker rating for your engine. Start instead with the Hulkman or GOOLOO blocks below, and size from the diesel column only.
NOCO GB40: pair it with
Pair it with its own faster sibling for a two-vehicle household: keep the GB40 in the car and the GBX45, with its 60W USB-C charging, in the vehicle that does longer trips.
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Fitment fineprint: 12V lead-acid vehicles within the maker ratings above. Tier position checked at research time — confirm the listing still sits inside this tier before buying, as pricing in this class moves with promotions.
Tip: recharge the GB40 after every use and check it on a calendar reminder, not after a failure. Our guide to how long a battery carries a load explains why small packs feel empty sooner than expected.
Fastest Recharge: NOCO Boost X GBX45
Fastest Recharge — the USB-C pick for drivers who hate waiting on a pack
Why the NOCO GBX45 is our pick
The GBX45 fixes the GB40-generation complaint that matters most in real ownership: refill time. NOCO rates it at 1,250A for 6.5L gas and 4.0L diesel, adds 60W USB-C Power Delivery in both directions, and states a 48-minute full recharge — or enough charge for a jump after five minutes from flat. If a jump pack is only useful when it is ready, recharge speed is a starting feature, not a convenience.
NOCO GBX45 key specs
- Part number: GBX45
- Peak current: 1,250A
- Maker engine rating: Gas up to 6.5L; diesel up to 4.0L
- Starts per charge: Maker listings conflict: up to 6 (US) vs up to 8 (UK) — unresolved
- Internal battery: 31 Wh lithium-ion
- USB-C input/output: 60W Power Delivery, profiles to 20V/3A
- USB-A output: 5V, 2.1A, 10W max
- Safety: Spark-proof and reverse-polarity protection (UltraSafe line)
- Housing: IP65 (ports closed)
- Recharge time: 48 minutes (maker, USB-C PD); jump-ready in 5 minutes
- Light: 100-lumen LED
- Weight: 1.30 lb unit; 2.16 lb with clamps
- Warranty: 1-year limited
NOCO GBX45: fits and best for
Gas cars and SUVs to 6.5L and diesels to 4.0L, especially in households that will actually keep a pack charged because it refills from the same USB-C PD charger as a laptop. It suits commuters, rideshare and delivery drivers, and anyone who wants one power bank that can also start the car — within the honest limit that jump reserve comes first.
NOCO GBX45 pros and watch-outs
Pros
- 60W USB-C PD in and out — the modern charging standard, both ways
- Maker-stated 48-minute full recharge; 5 minutes to a jump
- More diesel headroom than the GB40 (4.0L vs 3.0L)
- Very light even with clamps (2.16 lb)
- Refills from the laptop charger already in the house
Watch-outs
- Starts-per-charge figures conflict between maker listings (6 vs 8)
- 1-year warranty, like the rest of the NOCO line here
- Small 31Wh pack — laptop charging and jump reserve compete
- No status display; LEDs only, unlike the Hulkman and GOOLOO
NOCO GBX45: what owners report
Dedicated long-term owner coverage of the GBX45 specifically is thinner than for the older GB40 — said plainly rather than borrowed from other Boost X models. The owner record that exists, on its Amazon listing, centres on the fast recharge and compact size, which matches the spec sheet: this is a convenience-led pick.
The cautionary theme from GB40 owners on IH8MUD applies to the whole compact class: a totally flat battery in a large vehicle is where small packs run out of overhead, whatever the badge. Size from the litre rating, not from hope.
NOCO GBX45: who should not buy
If your diesel is above 4.0L, this pack is below its maker rating for your engine — move to the Hulkman or GOOLOO blocks below. If you want a screen that tells you pack state in plain language, the GBX45 LEDs will frustrate you; that is the Hulkman case.
NOCO GBX45: pair it with
Pair it with the GB40 as the household second pack: same NOCO protection logic and clamp style in both cars, so nobody has to learn two different units at the roadside.
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Fitment fineprint: 12V lead-acid vehicles within the maker ratings above. The 48-minute refill needs a genuine 60W-class USB-C PD charger; a small phone brick will not deliver it.
Tip: keep the PD brick with the pack, the way you would keep the right cable with electric truck gear — a fast pack charged slowly is just a slow pack.
Best for Cold Weather: Hulkman Alpha 85S
Best for Cold Weather — pre-heat, a real display, and ratings for large engines
Why the Hulkman Alpha 85S is our pick
The Alpha 85S is built around the two moments compact packs fail: deep cold and user uncertainty. Hulkman publishes a -40F working-temperature rating with pre-heat, a smart display that shows status and errors in plain form, and ratings of 8.5L gas and 6.0L diesel from a 74Wh pack. Its USB-C output is only PD18W — the display and the cold rating, not power-bank speed, are what you are buying in this tier.
Hulkman Alpha 85S key specs
- Part number: Alpha 85S
- Peak current: 2,000A
- Maker engine rating: Gas up to 8.5L; diesel up to 6.0L (official spec page; an Amazon summary printing 6.5L diesel conflicts)
- Starts per charge: Up to 60 (maker comparison table)
- Internal battery: Lithium-polymer, 74Wh / 20,000mAh at 3.7V
- USB-C input: 65W speed charge (SC) / PD18W
- USB-C output: PD18W
- USB-A output: QC3.0 18W
- DC output: 15V/10A, 150W max
- Operating temperature: -40F to 113F working (official spec page)
- Display / light: Smart display; LED light (maker listings)
- Weight: 2.57 lb (product, official spec page; kit weights vary by listing)
- Warranty: 2 years, maker-stated
Hulkman Alpha 85S: fits and best for
Cold-climate cars, SUVs and trucks, gas to 8.5L and diesel to 6.0L — including half-ton diesels that are past the GBX45 rating. It fits drivers who want the unit to tell them what is wrong instead of blinking a code, and anyone whose vehicle sleeps outside in winter. The full specification is on the Hulkman Alpha 85S official specification page.
Hulkman Alpha 85S pros and watch-outs
Pros
- Pre-heat technology with a -40F working rating — the cold pick
- Smart display shows charge, status and errors clearly
- Strong diesel rating (6.0L) for a pack this size
- 65W speed charge: maker states about 1.5 hours to full
- 2-year maker-stated warranty — the longest NOCO-alternative paper here
Watch-outs
- The 65W wall charger is not included — budget for it
- USB-C output is only PD18W, weak for laptops
- Maker and listing figures conflict in places (diesel rating, kit weight)
- Owner coverage is thinner than NOCO long-run models
Hulkman Alpha 85S: what owners report
Owner and review coverage collected for this model centres on three recurring points, summarised from its Amazon owner listing: the display makes first use calmer, pre-heat is the reason cold-climate buyers chose it, and the missing wall charger is the recurring annoyance.
Hulkman user-guide material, reproduced at ManualsPlus, shows the force-start mode and its warning that auto-detection and safety features are disabled in that mode — worth knowing before you need it, and a reason the display matters.
Hulkman Alpha 85S: who should not buy
If you mainly want a fast laptop power bank, PD18W output is the wrong tool — the GBX45 or GT4000S charge devices far faster. If your diesel is above 6.0L, this pack is below rating; the GOOLOO blocks are yours.
Hulkman Alpha 85S: pair it with
Pair it with the compact GB40 for a second, warmer-climate vehicle: the Hulkman covers the truck in winter, the NOCO covers the car all year.
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Fitment fineprint: 12V lead-acid vehicles within the maker ratings above; official spec-page figures govern where listings conflict, as printed in the spec list.
Tip: let pre-heat finish before cranking in deep cold. Forcing repeated cranks wastes the reserve the pre-heat is protecting, the same patience rule as using powered recovery gear properly.
Strongest Litre Ratings: GOOLOO GT4000S
Strongest Litre Ratings — the output pick for engines past the other ratings in this tier
Why the GOOLOO GT4000S is our pick
The GT4000S exists in this guide for one honest reason: its maker ratings go where the others stop — 12.0L gas and 10.0L diesel, with 4,000A peak, a published 800A starting-current figure, 100W two-way USB-C and a 3.2-inch status screen. That reach comes with the messiest owner record in the guide, printed in full below. Buy it for rating coverage and charging speed, with your eyes open.
GOOLOO GT4000S key specs
- Part number: GT4000S
- Peak current: 4,000A; starting current 800A for 3s (maker)
- Maker engine rating: Gas up to 12.0L; diesel up to 10.0L
- Starts per charge: Up to 60 (maker listing)
- Internal battery: 20,000mAh lithium-polymer (Amazon item details; Wh figures conflict across listings)
- USB-C input/output: 100W Power Delivery two-way; full charge about 1.2 hours (maker)
- Other outputs: USB QC3.0 18W; USB 5V/2.4A; DC 15V/10A, 150W max
- Safety: Protection list incl. overcharge, overload, short-circuit and reverse polarity (maker)
- Housing: IP65 (maker spec reproductions)
- Operating temperature: -20C to +60C (maker)
- Light / display: 400-lumen LED, 3 modes; 3.2-inch status screen
- Weight: About 4.9 lb (maker spec reproductions)
- Warranty: 18 months (Amazon manufacturer warranty description; some listings print 2 years)
GOOLOO GT4000S: fits and best for
Large gas engines, diesels between 7.0L and 10.0L, tractors, boats and mixed fleets kept by one household — anywhere the Hulkman diesel ceiling is the problem. It also fits power users: 100W USB-C in and out makes it the fastest-refilling pick here and able to charge a laptop at full speed, and the DC outlet runs inflators and inverters within its 150W limit. The brand comparison behind it is our NOCO vs GOOLOO head-to-head.
GOOLOO GT4000S pros and watch-outs
Pros
- Strongest numbered maker litre ratings in the guide, gas and diesel
- 100W two-way USB-C — fastest refill and device charging here
- Published starting-current figure, not just a peak headline
- Status screen shows charge and mode at a glance
- DC outlet powers separate inflators and 12V gear
Watch-outs
- Mixed owner record — charging faults and error codes reported by some owners
- Capacity and warranty figures conflict across listings
- Clamps reported awkward on side-post batteries
- Heavier than the compact picks at about 4.9 lb
GOOLOO GT4000S: what owners report
On AR15.com, owners split sharply: several report GT-line units with charging problems, error codes and weaker-than-expected output even after a replacement, while others in the same thread report owning many units across cars and a work truck — used on diesels, tractors and loaders — without a failure. Both halves are printed because both are the record.
An Amazon owner report reproduced in a review roundup describes a fully charged GT4000S failing to crank a nearly dead 5.3L V8 that a smaller NOCO then started, and criticises the clamp covers on side-post terminals — see the summary at Smart Auto. Treat the litre ratings as coverage, not as a guarantee on a destroyed battery.
GOOLOO GT4000S: who should not buy
If reliability record matters more than rating reach, do not buy this pack — the Hulkman covers diesels to 6.0L with a cleaner record in this guide, and the GP4000 below carries the same 10.0L diesel rating in a simpler unit. If your engine is inside NOCO ratings, the GOOLOO extra reach buys you nothing but the conflicts above.
GOOLOO GT4000S: pair it with
Pair it with the JNC660 in a workshop: the GOOLOO travels in the truck for its rating reach, the lead-acid box stays plugged in at base for repeated starts.
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Fitment fineprint: 12V lead-acid vehicles within the maker ratings above. Wh and warranty figures conflict across listings — the Amazon item-details figures for this ASIN are the ones printed here.
Tip: on side-post batteries, seat the clamps deliberately and check the screen for a ready indication before cranking — the clamp fit is the documented weak point. General clamp discipline is in our accessories guide.
Best Value Power: GOOLOO GP4000
Best Value Power — the rating ceiling of the value line, without the screen tax
Why the GOOLOO GP4000 is our pick
The GP4000 is the sibling head-to-head verified power pick, and in this tier it is the value route to the top ratings: 4,000A, a maker rating for all gas engines and diesels to 10.0L, a DC outlet for 12V accessories, and an included EVA case. What it gives up against the GT4000S is the screen and the 100W charging — its USB-C input is 15W on the maker chart. Buy the ratings, accept the simpler unit, and read its listing conflicts in full below.
GOOLOO GP4000 key specs
- Part number: GP4000
- Peak current: 4,000A
- Maker engine rating: All gas engines; diesel up to 10.0L
- Internal battery: Capacity conflict: 24,000mAh (retailer spec sheet) vs 26,800mAh / 99.2Wh (comparison review) — printed as conflict
- USB outputs: USB-A Quick Charge 18W (maker chart)
- USB-C: In/out, 15W input (maker chart)
- DC output: 15V/10A
- Safety: Smart clamps; maker protection list (see head-to-head detail)
- Operating temperature: -4F to 140F
- Cycle life / standby: Over 1,000 cycles; standby over 12 months — listing advises recharge every 2–3 months, manual every 3–6 months (conflict)
- Light: LED flashlight, 3 modes
- Weight: Conflict: 3.41 lb vs 3.94 lb across listing variants — printed as conflict
- Warranty: 18 months plus lifetime tech support (listing)
GOOLOO GP4000: fits and best for
Large gas engines of any size on the maker rating, diesels from 8.0L to 10.0L, and mixed households whose biggest vehicle rules out the compact picks. It also fits buyers who want the DC outlet to run inflators and 12V gear without paying for a status screen. The full verified comparison against the NOCO line is our NOCO vs GOOLOO head-to-head.
GOOLOO GP4000 pros and watch-outs
Pros
- Top-tier maker ratings, gas and diesel, in a value unit
- DC outlet powers separate inflators and 12V accessories
- EVA storage case included
- 18-month warranty is longer than the NOCO paper here
- Over 1,000-cycle service life claim
Watch-outs
- Wall charger not included
- Capacity and weight figures conflict across listings
- Recharge advice conflicts between listing and manual
- USB-C charging is slow (15W input) next to the GT4000S
GOOLOO GP4000: what owners report
On BobIsTheOilGuy, a GOOLOO owner reports repeated successful starts up to a 5.7L Hemi Ram and helping stranded drivers, while the same thread cautions that an old 7.3L Power Stroke in a Midwest winter is where the bigger packs earn their keep — exactly the GP4000 use case.
On the AR15 forum, owners of both brands report both work to spec, with GOOLOO packs noted for holding charge longer in storage and a NOCO manual-override start on a completely dead battery reported approvingly. AutoGuide keeps a GOOLOO as its garage most-used pack, praising wide-opening clamps.
GOOLOO GP4000: who should not buy
If your engine is inside GB40 or GBX45 ratings, the extra reach buys you nothing but weight — buy the compact tier. If you want the screen and 100W refill, that is the GT4000S above, not this unit. Above 10.0L diesel, nothing in this guide is rated for you.
GOOLOO GP4000: pair it with
Pair it with the GT4000S for a two-vehicle household that wants a screen in one vehicle and value power in the other: same rating reach, two different charging experiences.
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Fitment fineprint: 12V lead-acid vehicles within the maker ratings above. Hybrid and plug-in hybrid fitment is not claimed in the listing material checked — confirm your model jump points before use.
Tip: follow the stricter recharge advice where listing and manual conflict — top up every two to three months in storage. More on pack care sits with our maintenance checklist.
Best Lead-Acid Shop Box: Clore Jump-N-Carry JNC660
Best Lead-Acid Shop Box — reserve, cable reach and a built-in charger — the shop standard
Why the Clore JNC660 is our pick
The JNC660 is the anti-lithium pick, and shops keep buying it for reasons the spec sheet explains: a 22Ah lead-acid battery with far more reserve than any lithium pack here, 425 cranking amps behind the 1,700 peak figure, 46 inches of #2 AWG cable that actually reaches awkward batteries, and a built-in automatic charger so the box lives plugged in and ready. Clore publishes no litre rating — it rates the box for all vehicles and light commercial use — so we print that, not an invented number.
Clore JNC660 key specs
- Part number: JNC660
- Peak current: 1,700A; cranking amps 425
- Maker engine rating: All vehicles, light commercial (no litre rating published)
- Internal battery: 22Ah Clore Proformer lead-acid AGM
- Cables: 46 in, #2 AWG, heavy-duty clamps
- Charging: Built-in automatic charger; 12V charging cable included
- Outputs: 12V DC outlet for accessories (no USB published)
- Charge indicator: Voltmeter showing onboard battery status
- Safety: Grip guards on clamps; no spark-proof electronic protection published — connect carefully
- Light: None built in
- Weight: 18 lb
- Warranty: 1-year limited
Clore JNC660: fits and best for
Workshops, farms, fleets, tow and lot work — anywhere starts are repeated, batteries are deeply flat, and the box returns to a wall socket afterwards. It also fits owners who keep vehicles, tractors and boats in one place and want one box that can start them in sequence, power 12V accessories while working, and have its internal battery replaced years later instead of scrapping the unit.
Clore JNC660 pros and watch-outs
Pros
- Reserve capacity dwarfs every lithium pack here (22Ah)
- Long, heavy #2 AWG cables reach real-world battery positions
- Built-in automatic charger — leave it plugged in, always ready
- Cranking amps published (425), not just a peak headline
- Internal battery is replaceable — the box is not disposable
Watch-outs
- 18 lb — it travels by handle, not in a glovebox
- No litre rating, USB ports, display or built-in light
- Lead-acid battery needs periodic charging and eventual replacement
- No published electronic spark-proof protection — technique matters
Clore JNC660: what owners report
On the JL Wrangler Forums, the JNC660 enters the discussion as the tow-truck class answer: a poster notes its 22Ah battery against a small lithium pack, and the original poster buys one alongside keeping the NOCO — reserve in the shop, lithium in the vehicle.
On TractorByNet, an owner reports twelve years from a JNC660 kept plugged in, starting a big diesel truck, calling the brand a dealer go-to for power and longevity; on Yesterdays Tractors, owners discuss replacing its internal battery rather than replacing the box. Weight is the constant complaint, and the constant trade.
Clore JNC660: who should not buy
If the pack must live in a car, travel in luggage, or be carried by someone who will not lift 18 lb to a battery, do not buy this box — any lithium pick here is the right shape. If you need USB-C device charging, the JNC660 simply does not offer it.
Clore JNC660: pair it with
Pair it with the GB40: the Clore stays plugged in at base for hard and repeated starts, the NOCO travels in the vehicle for the one-start emergency away from home.
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Fitment fineprint: 12V vehicles and light commercial use per the maker table; no litre rating is published or implied for this model. Recharge after every use — lead-acid life is decided by never sitting flat.
Tip: leave the JNC660 on its built-in charger between jobs. The same storage discipline is behind protecting gear that lives ready and our maintenance checklist.
Spec comparison
All six picks side by side, on maker-published figures only. Where a maker publishes nothing, or listings conflict, the cell says so — that honesty is part of the comparison in this tier.
| Spec | GB40 | GBX45 | Hulkman 85S | GT4000S | GP4000 | JNC660 |
|---|---|---|---|---|---|---|
| Peak current | 1,000A | 1,250A | 2,000A | 4,000A | 4,000A | 1,700A |
| Cranking / starting current | Not published | Not published | Not published | 800A for 3s (maker) | Not published | 425 cranking amps |
| Gas rating | 6.0L | 6.5L | 8.5L | 12.0L | All gas (maker) | No litre rating published |
| Diesel rating | 3.0L | 4.0L | 6.0L | 10.0L | 10.0L | No litre rating published |
| Internal battery | Lithium-ion, Wh not published | 31 Wh lithium-ion | 74Wh lithium-polymer | 20,000mAh lithium-polymer | Capacity conflicts | 22Ah lead-acid AGM |
| Starts per charge (maker) | Up to 20 | Up to 6–8 (listings conflict) | Up to 60 | Up to 60 | Not published | Not published |
| Fastest recharge | Micro-USB (slow) | 60W USB-C PD, 48 min | 65W speed charge, about 1.5 h | 100W USB-C PD, about 1.2 h | USB-C 15W input | Built-in AC charger |
| Device output | USB 5V/2.1A | USB-C 60W PD | USB-C PD18W | USB-C 100W PD; DC 150W | USB QC; DC 15V/10A | 12V DC outlet |
| Operating temperature | -20C to +50C | Not published | -40F to 113F | -20C to +60C | -4F to 140F | Not published |
| Weight | 2.4 lb | 2.16 lb with clamps | 2.57 lb | About 4.9 lb | 3.41–3.94 lb (conflict) | 18 lb |
| Warranty | 1 year | 1 year | 2 years (maker-stated) | 18 months | 18 months | 1 year |
| Check Price |
Installation & wiring basics
There is nothing to install — fitment for a jump pack means matching the pack to the vehicle before the bad morning, and the connection order when it comes. Connect red to the positive terminal, then black to a solid unpainted ground on the engine or chassis away from the battery. Power the pack on, wait for its ready indication or display, and crank in short attempts. Remove the clamps in reverse order once the engine runs. Background on what a cranking load actually draws is in how many amps a 12V load draws and budget truck electrics.
Fitment notes that bite in this tier: side-post batteries punish shallow clamp contact on any pack — the documented GT4000S complaint — so seat clamps deliberately and check the screen or ready light before cranking. Dual-battery diesels may need the pack left connected briefly before a crank attempt. A hybrid or plug-in vehicle is jumped only at its published 12V jump points, never at the traction battery. And store a lithium pack in the cab, not the bed, so it stays inside its temperature range — the same storage logic as truck gear that lives in the vehicle.
Safety essentials
Six rules that outrank every pick in this guide:
- Connect red to positive first and black to a ground away from the battery; remove them in reverse order.
- Never use manual override or force-start as a first step — it disables the protections that make these packs safe.
- Keep sparks, flames and smoking away from a battery being jumped; batteries vent hydrogen, especially after deep discharge.
- Stop and reassess after a few short crank attempts — repeated cranking overheats starters, clamps and packs.
- Never charge a lithium pack below freezing or store any pack in a hot closed vehicle beyond its rating.
- A swollen, cracked, hot or leaking pack is finished — do not charge it, jump with it, or store it indoors near exits.
NOCO GBC013 case for the GB40 — the fitted EVA case listed for the GB20 and GB40 in the verified pool, so clamps and cable stay together in the glovebox. The full category is our portable jump starters archive.
Check Price — NOCO GBC013 case
NOCO GENIUS5 maintainer — the verified-pool 5A charger and maintainer that stops a weak vehicle battery needing jumps in the first place; see also battery sizing and health.
Energizer jumper cables, 16-foot 6-gauge — the verified-pool donor-vehicle backup for the day a pack is flat or an engine defeats it; the wider kit list is in essential accessories and recovery kit picks.
Check Price — Energizer cables
Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| Clicks but no crank | Weak clamp contact, a battery too flat to detect, or a pack below its rating for that engine | Reseat clamps on clean metal, check pack charge, leave it connected a minute, then use the maker force or override mode only as directed — and if the engine is above the pack rating, use a bigger pick from this guide |
| Pack will not switch on or take charge | Pack deeply discharged in storage or charging outside its temperature range | Bring it indoors to room temperature, use the maker cable and a charger of the right wattage, and leave it connected — deeply flat packs can take time to wake |
| Error light, code or clamp alert at connection | Reverse polarity, shorted clamps, or a vehicle battery fault | Remove both clamps, check terminal markings in daylight, reconnect in the correct order; a repeated alert on a correct connection points at the vehicle battery |
| Starts once, then nothing on the second attempt | Reserve spent by repeated cranks, device charging, or a cold-soaked pack | Recharge fully before judging the pack; in cold, warm a lithium pack indoors first or use the pre-heat pick, and charge the vehicle battery properly between attempts |
| Swollen or hot pack | Internal cell damage or age — a safety fault, not a performance fault | Stop using and charging it immediately, move it away from flammables outdoors if safe to do so, and follow local battery-disposal rules; never puncture or open it |
| Vehicle starts, then dies when the pack is removed | The vehicle battery cannot hold charge or the alternator is not charging | The pack did its job — the vehicle needs a battery or charging-system repair, ideally with a maintainer from the safety section, not a bigger pack |
Who should NOT buy these
Your diesel is above 10.0L, or your system is 24V. Nothing in this tier is rated for you — the strongest diesel ratings here stop at 10.0L and every pick is a 12V unit. Step up to the full field in our pillar guide instead of guessing bigger inside a tier page.
A budget pick honestly covers your car. If your vehicle is a small or midsize gas car, the core picks in our budget guide cover it for less. This tier earns its keep on diesel reach, cold technology, screens and refill speed — features a small-car owner may never use.
Your battery is failing, not flat. A jump pack revives a discharged battery for a trip; it does not repair a sulphated, shorted or frozen one. If the same vehicle needs jumps weekly, spend on the vehicle battery and a maintainer first.
You will not maintain a pack. Every unit here self-discharges in storage. If nobody will check and recharge it on a schedule, it will be flat on the day it is needed, whatever the standby claim on the box says.
You fly with your tools. Lithium packs are carry-on only and airlines apply watt-hour limits — the larger packs here run to 74Wh, close to common limits. Check your airline exact rules before travelling, and never pack any of them in checked baggage.
Final verdict
- Best Overall — NOCO Boost Plus GB40: Check its price
- Fastest Recharge — NOCO Boost X GBX45: Check its price
- Best for Cold Weather — Hulkman Alpha 85S: Check its price
- Strongest Litre Ratings — GOOLOO GT4000S: Check its price
- Best Value Power — GOOLOO GP4000: Check its price
- Best Lead-Acid Shop Box — Clore Jump-N-Carry JNC660: Check its price
Start from your engine and fuel, not from an amp headline: the calculator at the top lands most drivers on the GB40 or GBX45, cold-climate and mid-diesel owners on the Hulkman, and only genuinely large engines on the GOOLOO pair. Shops should skip the lithium argument entirely and buy reserve. The head-to-head behind two of these brands is NOCO vs GOOLOO, and the full field is ranked in the pillar guide.
FAQ
What is the best jump starter in this tier for most drivers?
On maker ratings and owner record, the NOCO GB40: 6.0L gas and 3.0L diesel coverage at 2.4 lb covers most family vehicles, with the deepest owner record in this guide. Drivers who value refill speed over that record land on the GBX45 instead — a little more rating, and a 48-minute USB-C PD refill. Size from the calculator, not from peak amps.
Can a jump starter in this tier start a heavy-duty diesel?
Yes, within the diesel column — and only there. The diesel ratings here run from 3.0L on the GB40 to 6.0L on the Hulkman and 10.0L on both GOOLOO units, which covers the common 6.6L and 6.7L heavy-duty diesels with headroom. Above 10.0L diesel, nothing in this guide is rated, and the calculator says so instead of guessing.
Is the GT4000S or the GP4000 the better GOOLOO buy?
They share the 10.0L diesel ceiling and differ in everything around it. The GT4000S adds a 3.2-inch screen, 100W two-way USB-C and a published starting-current figure; the GP4000 is the simpler value unit with a 15W USB-C input, an included case and more listing conflicts. The head-to-head context is in our NOCO vs GOOLOO comparison, linked in the researched card.
Are peak-amp ratings trustworthy in this tier?
Treat them as headlines, not measurements. Peak current is a brief maximum with no shared test standard, which is why this guide sizes by maker litre ratings and prints starting or cranking figures where a maker publishes them — 800A for three seconds on the GT4000S, 425 cranking amps on the Clore. When two packs claim the same amps for different ratings, believe the rating.
How long will these packs hold their charge?
Months, not years, and it varies by chemistry and temperature. The GP4000 listing advises a top-up every two to three months while its manual says three to six — follow the shorter interval. Lithium packs hold storage charge well but still need scheduled checks; the lead-acid Clore is happiest left on its built-in charger. Recharge after every use, regardless of claims.
Can these packs start a completely dead battery?
Sometimes — that is what override and force modes are for, when a battery is too flat for the pack to detect. The GB40 override and the Hulkman force mode both exist for this case, and owner reports in this guide show both successes and a compact-pack failure on a totally flat large SUV. A battery that has failed internally will not be saved by any pack here.
Is lithium or lead-acid better for a shop?
Lead-acid, on reserve and duty. The JNC660 22Ah battery delivers repeated starts, powers 12V accessories while you work, and can be replaced when it ages — at 18 lb and with no modern ports. Lithium wins everywhere portability matters. Owner sources in this guide run both: a lead-acid box at base and a lithium pack in the vehicle.
Can I take one of these jump starters on a plane?
Lithium jump starters are carry-on items only, never checked baggage, and airlines apply watt-hour limits. The packs here range from 31Wh to 74Wh, so check your airline exact limit for the larger units before travelling. The lead-acid Clore is not flight luggage at all. Rules change; the airline, not this guide, is the authority.
Why do listings disagree on specs for the same model?
Variant listings, regional pages and retailer reproductions drift apart, and brands update pages without notes. This guide prints the conflicts it found — GBX45 starts per charge, GT4000S capacity and warranty, GP4000 capacity, weight and recharge advice — and governs by the maker page or the Amazon item details for the exact ASIN linked. Check the fineprint under each pick before buying.
When should I skip this tier entirely?
Downward, when a budget pick covers your small gas car — the budget guide linked above is the honest route. Upward, when the requirement is a diesel above 10.0L, a 24V system, or the upper-tier lithium flagship class excluded from this guide. A pack bought against the wrong tier requirement is not a saving — it is a second purchase waiting to happen.
Sources & changelog
Manufacturer sources
- NOCO GB40 listing and manual, GBX45 listing and spec table: GB40 on Amazon, GBX45 on Amazon, GB40 manual (manuals.plus)
- Hulkman Alpha 85S official specifications and listing: hulkman.com Alpha 85S specifications, Alpha 85S on Amazon
- GOOLOO GT4000S and GP4000 listings and maker specifications: GT4000S on Amazon, GP4000 on Amazon
- Clore Jump-N-Carry JNC660 listing and specifications: JNC660 on Amazon
Owner sources (paraphrased in the blocks above)
- Bogleheads — portable booster discussion: repeated GB40 use, clamps and override
- IH8MUD — lithium jump starter thread: the compact-pack overhead counter-report
- AR15.com — GOOLOO GT4000/GT4000S thread and AR15 forum — GOOLOO or NOCO verdict: the split GOOLOO record and brand balance
- BobIsTheOilGuy — high performance jumper starters and AutoGuide — best portable car jump starters: GOOLOO starts to a 5.7L Hemi and garage use
- JL Wrangler Forums — NOCO and dead battery, TractorByNet — portable jump starter and Yesterdays Tractors — jump box: JNC660 reserve, longevity and battery replacement
Changelog — October 16, 2026: guide first published.
By Leo, Founder, WinchInsider
Leo researches vehicle gear the slow way: manufacturer manuals, warranty fine print and owner forums, with every conflict printed rather than smoothed over and no claim of hands-on testing anywhere on the site. Questions and corrections are welcome via our contact page; how affiliate links work is on our affiliate disclosure. More is on our about page.
Related guides
- Best portable jump starter — the pillar guide
- Best portable jump starter under the budget tier
- NOCO vs GOOLOO jump starter — head-to-head
- Portable jump starters — the category hub
- Best winch battery — sizing and battery health
- How many amps does a 12V winch draw?