GOOLOO and AVAPOW sell the same promise two different ways. GOOLOO leads with hardware theatre: a 3.2-inch status screen, 100-watt two-way USB-C charging and maker ratings to 12.0 litres of gas on its GT4000S. AVAPOW leads with value arithmetic: a 4,000-amp A37 that publishes an IP65 shell and 60-watt PD charging, and an A28 whose diesel rating matches its gas rating at 8.0 litres. Neither brand documents itself perfectly — GOOLOO’s own listings disagree on capacity and weight, and AVAPOW publishes less paperwork than either rival in our NOCO vs GOOLOO comparison — so this head-to-head prints each maker’s figures exactly as sourced, conflicts included, across two packs per brand. The full field sits in our pillar guide to the best portable jump starter.
Read the amp badges last. Peak amps carry no shared test standard between brands, so a 4,000A badge on both sides of this comparison still proves nothing by itself. The rows that route a purchase are the makers’ own engine-litre ratings, starts per charge, charging inputs, temperature floors and warranty evidence — the same basis used across our portable jump starters archive and jump starter comparisons, and the only basis the finder below is allowed to use.
How we researched this guide
We compared 4 jump starters head-to-head, two per brand, all from verified research pools. The GOOLOO GT4000S and GP4000 come from the pools behind our pillar guide and our NOCO vs GOOLOO comparison (maker listings, the GOOLOO product page and manual records, checked October 15, 2026). The AVAPOW A28 comes from our budget guide’s pool (Amazon listing and technical details, October 16, 2026), and the AVAPOW A37 was verified fresh on October 17, 2026 from its Amazon listing and spec table. Where sources disagree — and on the GT4000S they disagree on capacity, weight and warranty — the conflict is printed in the open, never quietly resolved. We do not test jump starters, and no prices appear in this guide; our method is the one described in our affiliate disclosure.
We reviewed owner reports across 5 sources — AR15.com, BobIsTheOilGuy, AutoGuide, Bogleheads and the packs’ own Amazon owner listings — paraphrased and linked in each owner section. GOOLOO coverage is forum-deep and mixed; AVAPOW long-term coverage is thin for both models, and both AVAPOW blocks say so instead of borrowing stories from other models. A fifth AVAPOW, the A68, was checked and excluded: its starts, capacity and warranty were not published in the sources we could verify, so no honest product block could be written for it.
The 30-second answer
Want the most complete pack regardless of brand: buy the GOOLOO GT4000S — rated to 12.0L gas and 10.0L diesel, 100W two-way charging, a status screen and an IP65 shell. Want GOOLOO output with the case included and no screen to pay for: buy the GOOLOO GP4000, rated for all gas engines and diesels to 10.0L. Want AVAPOW value with the strongest diesel rating in its class: buy the AVAPOW A28, rated to 8.0L of both fuels. Want AVAPOW’s modern flagship: buy the AVAPOW A37 — 10.0L gas and diesel ratings, IP65 and 60W PD charging. Diesel beyond 10.0L: no pack in this comparison is rated for it, and the finder says so rather than stretching one.
Best Overall in This Comparison
GOOLOO GT4000S
Best if you want one pack that does everything: the widest GOOLOO ratings here, the fastest recharge in the comparison, a screen that shows charge and errors at a glance, and a 15V DC port for accessories.
Best GOOLOO Value
GOOLOO GP4000
Best if you want GOOLOO output without the flagship extras: an all-gas maker rating, a 10.0L diesel rating, an EVA case in the box and an 18-month warranty with lifetime tech support.
Best AVAPOW Diesel Value
AVAPOW A28
Best if your diesel is the problem engine: maker ratings of 8.0L gas and 8.0L diesel, up to 50 starts per charge on its listing, a force-start mode and a 12V DC port, in the lightest AVAPOW class here.
Best AVAPOW Overall
AVAPOW A37
Best if you want AVAPOW’s full-size answer to the GT4000S: 10.0L ratings for both fuels, up to 60 starts per charge, an IP65 shell and 60W two-way PD charging through a single Type-C port.
Quick compare — all four packs on their makers’ published facts. Peak amps are each maker’s own claim and are not cross-comparable; route on the litre ratings.
| Pack | Peak amps (maker) | Engine rating | Starts / charge | Fastest charging in | Warranty | Check Price |
|---|---|---|---|---|---|---|
| GOOLOO GT4000S | 4,000A | Gas 12.0L / diesel 10.0L | Up to 60 | USB-C PD 100W | 18 months (conflict noted) | Check Price |
| GOOLOO GP4000 | 4,000A | All gas / diesel 10.0L | Not published | USB-C (15W input per maker chart) | 18 months + lifetime tech support | Check Price |
| AVAPOW A28 | 3,000A | Gas 8.0L / diesel 8.0L | Up to 50 (listing) | Type-C up to 12V/1.5A | 2 years (listing-stated) | Check Price |
| AVAPOW A37 | 4,000A | Gas 10.0L / diesel 10.0L | Up to 60 | USB-C PD 60W | Not published | Check Price |
GOOLOO or AVAPOW finder
Enter your engine size in litres, pick the fuel, and say whether a brand matters to you. Every answer recommends one of this article’s four packs with its button, routed only on the makers’ own litre ratings — never on peak amps, and never to a pack below the rating for the engine you entered.
How to choose between GOOLOO and AVAPOW
Engine ratings first, and diesel ratings twice
Every routing decision in this comparison runs on the makers’ litre ratings: GT4000S at 12.0L gas and 10.0L diesel, GP4000 at all gas and 10.0L diesel, A37 at 10.0L of both, A28 at 8.0L of both. Diesel is where packs get exposed, because compression and glow-plug load punish a small pack, so read the diesel column before the gas headline. An engine inside both brands’ ratings is a free choice; an engine inside only one is not a choice at all.
Recharge speed: a real, widening gap
GOOLOO’s flagship takes 100W two-way USB-C and claims a full charge in about 1.2 hours, with a 5-minute charge said to be enough for a start. AVAPOW’s A37 answers with 60W PD through one Type-C port and a roughly 2-hour full charge on that input. The GP4000 and A28 sit a generation behind on paper, on 15W-class and 12V/1.5A Type-C inputs respectively. A pack that recharges fast is a pack that is actually ready when the second car fails.
Screens, shells and the evidence for both
The GT4000S shows its state on a 3.2-inch screen; the AVAPOW pair rely on clamp lights and alerts, with the A37 adding a published IP65 shell the A28 does not claim. Treat a rating and a description differently: IP65 is a test standard a maker can be held to, while a dustproof, shock-resistant shell is a description. Both brands also publish clamp protection lists — ten SuperSafe protections on the GOOLOO flagship, eight protections on each AVAPOW — and both answer a fully flat battery, GOOLOO with its smart-clamp BOOST function and AVAPOW with force-start modes.
Capacity and weight: where both brands get vague
This is the comparison’s honesty test. GOOLOO’s GT4000S capacity appears as 20,000mAh in one Amazon item-details record and 24,000mAh in another, and its weight as both about 4.9 lb and 2.31 lb. The GP4000’s capacity and weight conflict the same way. AVAPOW publishes a clean 23,800mAh for the A28 but a conflicting watt-hour figure follows it, and the A37 publishes no capacity in the sources we verified at all. We print every conflict rather than picking the flattering number, and we suggest you do the same with any listing that will not commit.
Warranty: length against evidence
GOOLOO’s paper is the more checkable here: 18 months on both picks, with lifetime tech support named on the GP4000, though a marketplace listing claims 2 years for the GT4000S and we flag that. AVAPOW’s A28 carries a longer 2-year term that reaches us through retailer reproductions of its listing, and the A37’s model-specific term was not published in the sources we verified. A warranty you can point to in item details is worth more than a longer one you cannot.
What each brand is actually for
Step back and the brands separate cleanly. GOOLOO is the feature brand: screens, faster charging, a DC accessory port across its line and ratings that reach furthest on gas. AVAPOW is the value brand: diesel ratings that punch at or above its price class, simpler hardware and less paperwork. Drivers who already know they lean one way can test that instinct against the single-model sibling, our NOCO Boost Plus vs AVAPOW head-to-head, and against the emergency-focused field in our emergency jump starter guide.
Which engines each pack covers
Each row is routed on the makers’ own litre ratings. A pack is only listed as covering an engine inside its rating.
| Engine band | GOOLOO GT4000S | GOOLOO GP4000 | AVAPOW A28 | AVAPOW A37 |
|---|---|---|---|---|
| Gas up to 8.0L | Rated | Rated | Rated | Rated |
| Gas 8.0-10.0L | Rated | Rated | Not rated | Rated |
| Gas 10.0-12.0L | Rated | Rated | Not rated | Not rated |
| Gas over 12.0L | Not rated | Rated (all gas) | Not rated | Not rated |
| Diesel up to 8.0L | Rated | Rated | Rated | Rated |
| Diesel 8.0-10.0L | Rated | Rated | Not rated | Rated |
| Diesel over 10.0L | Not rated | Not rated | Not rated | Not rated |
The empty diesel row at the bottom is the honest one: beyond 10.0L diesel, this comparison has no covered pick, and the larger packs in the pillar guide and our mid-budget jump starter guide are the step-up route.
GOOLOO vs AVAPOW by budget
| Tier | What you get | Example pick from this comparison |
|---|---|---|
| Lowest entry in this comparison | Full 8.0L gas and diesel ratings and a force-start mode, without a screen or an IP rating | AVAPOW A28 |
| Mid tier, case included | All-gas coverage, a 10.0L diesel rating and an EVA case in the box | GOOLOO GP4000 |
| Flagship tier | A status screen, 100W two-way charging, IP65 and the widest gas rating here | GOOLOO GT4000S |
| Flagship value tier | 10.0L ratings for both fuels, IP65 and 60W PD charging | AVAPOW A37 |
No prices appear in this guide by policy, and both brands discount aggressively, so the tier order can shuffle at the listing. Judge the tier by what the pack includes and what its maker will put in writing, then confirm the live figure on each button.
Types of jump starter, compared
| Type | What it is | Pros | Cons | Best for |
|---|---|---|---|---|
| Screened flagship lithium | Full-size lithium pack with a status display — the GT4000S | Charge and error state at a glance; fastest recharging | Most to pay for; biggest case of its class | Drivers who use the pack often and run accessories from it |
| High-output lithium, no screen | Full-size lithium pack routed by clamp lights — GP4000 and A37 | Widest ratings per pack; simpler hardware | State shown by lights, not numbers | Big engines, diesels, two-vehicle households |
| Compact-mid lithium | Smaller lithium pack with full dual-fuel ratings — the A28 | Light, simple, strong diesel rating for its size | No IP rating published; slower charging | One diesel or V8 in the household, glovebox-to-trunk life |
| Lead-acid shop box | Traditional heavy box with a large reserve battery | Repeated starts all day; built for yard work | Very heavy; no glovebox life | Shops and yards (covered in the pillar guide) |
| Inflator combo | Jump pack with a built-in air compressor | Two roadside tools in one case | The compressor drains the same battery you need for starting | Drivers fighting slow leaks (compared in the pillar guide) |
The first three types are this comparison’s four packs. The lead-acid and combo rows carry their own picks in our pillar guide and in the budget jump starter guide, where the A28 also appears at its price tier.
Detailed reviews
Each pack is judged on its maker’s published specifications for the exact ASIN linked, with conflicts printed inside its own spec list. Owner sections paraphrase real reports and link them; where coverage is thin, the block says so.
Best Overall: GOOLOO GT4000S
GOOLOO flagship pick
Why the GOOLOO GT4000S is our pick
The GT4000S is the pack this comparison keeps coming back to, because GOOLOO built it to end arguments: the widest gas rating here at 12.0 litres, a 10.0-litre diesel rating, a screen that removes the guesswork from charge state and clamp errors, and 100-watt two-way charging that refills it in about 1.2 hours on the maker’s figures. Its paperwork is messier than its hardware — the capacity, weight and warranty conflicts are printed in its own spec list below — but on published ratings and features, it is the most complete pack of the four.
GOOLOO GT4000S key specs
- Part number: GT4000S
- Peak current: 4,000A (maker claim); starting current 800A for 3 seconds
- Engine ratings: gas up to 12.0L, diesel up to 10.0L (GOOLOO)
- Jump starts per charge: up to 60 (maker claim)
- Capacity: conflict — 20,000mAh in Amazon item details for this ASIN vs 24,000mAh in Amazon product info; watt-hour figures vary with them, so no single figure is asserted
- Charging input: USB-C PD 100W two-way; full charge about 1.2 hours; 5-minute charge claimed enough for a start
- USB outputs: QC3.0 18W + 5V/2.4A; DC output 15V/10A, 150W
- Display: 3.2-inch status screen; LED 400 lumens
- Housing: IP65; operating -20°C to +60°C; over 1,000 cycles (maker)
- Weight: conflict — about 4.9 lb in maker spec reproductions vs 2.31 lb in Amazon technical details
- Warranty: 18 months per Amazon manufacturer description (a marketplace list claims 2 years — conflict)
GOOLOO GT4000S: fits and best for
The one-pack household: a big gas V8 or a diesel to 10.0 litres, plus phones and a 12V accessory load between emergencies through its DC port. It is the finder’s default answer across most of this comparison’s range, and the natural step-up from the value field in our mid-budget guide. The discipline around it is the same one our winch battery guide teaches: the pack is the backup, not the battery plan.
GOOLOO GT4000S pros and watch-outs
Pros
- Widest gas rating here: 12.0L, with diesel to 10.0L
- Fastest recharge in the comparison: 100W two-way, about 1.2 hours
- 3.2-inch screen shows charge and clamp state directly
- IP65 housing and a 400-lumen light
- 15V/10A DC port runs accessories a USB-only pack cannot
Watch-outs
- Capacity figures conflict across its own listings (printed above)
- Weight figures conflict too — plan for the heavier one
- Warranty term conflicts between sources (18 months printed)
- Owner record is genuinely mixed, including charging complaints (below)
- Screen and output are flagship extras a simple car pack does not need
GOOLOO GT4000S: what owners report
The GOOLOO owner record is the deepest in this comparison and the least tidy. On AR15.com, owners of GOOLOO packs report them holding charge longer in storage than a rival brand’s packs, while other GT-line owners in the pillar research report charging issues and error codes alongside owners whose units have been faultless on diesels and equipment — a split record we print as a split record.
An Amazon owner report carried in the pillar research describes a GT4000S failing to crank a nearly dead 5.3-litre V8 where a smaller rival pack succeeded, with side-post clamp fit criticised; set against it, BobIsTheOilGuy owners report GOOLOO packs starting engines up to a 5.7-litre Hemi repeatedly and rescuing stranded drivers. Both directions are linked so you can weigh them yourself.
GOOLOO GT4000S: who should not buy
Skip it if your engines are small and your budget is the point — you would be paying for a screen, a DC port and ratings you will never use. Inside this comparison, the covered value answer is the GOOLOO GP4000, and the AVAPOW pair below undercuts it further.
GOOLOO GT4000S: pair it with
Pair it with a NOCO GENIUS5 maintainer on the vehicle itself: a 5A smart charger, maintainer and desulfator for 6V and 12V vehicle batteries, so the flagship stays an emergency tool instead of becoming a weekly routine.
We may earn a commission at no cost to you. Listing shown for the GOOLOO GT4000S, ASIN B09M9HQG73 — confirm the S suffix on the listing; the plain GT4000 is a different model.
Use the screen: check the pack’s charge monthly instead of guessing, the same habit our maintenance checklist sets for the rest of the truck.
Best GOOLOO Value: GOOLOO GP4000
GOOLOO value pick
Why the GOOLOO GP4000 is our pick
The GP4000 is the GOOLOO for buyers who read ratings and skip theatre. Its maker rating covers all gas engines outright — the only such claim in this comparison — and diesels to 10.0 litres, matching the flagship where it matters. What you give up is the screen, the 100-watt charging and the fast-charge headline; what you get back is an EVA case in the box, an 18-month warranty with lifetime tech support named in the listing, and the same 15V DC accessory port. Its capacity and weight figures conflict across sources, and both conflicts are printed below rather than smoothed over.
GOOLOO GP4000 key specs
- Part number: GP4000
- Peak current: 4,000A (maker claim)
- Engine ratings: all gas engines, diesel up to 10.0L (GOOLOO)
- Jump starts per charge: Not published
- Capacity: conflict — 24,000mAh on a retailer spec sheet vs 26,800mAh / 99.2Wh in a comparison review
- Charging input: USB-C in/out (15W input per maker comparison chart)
- USB output: USB-A Quick Charge 18W; DC output 15V/10A
- LED: 3 modes (solid, strobe, SOS); lumens not published
- Operating range: -4°F to 140°F (listing); over 1,000 cycles; standby over 12 months
- Weight: conflict — 3.41 lb vs 3.94 lb across listing variants
- Warranty: 18 months + lifetime tech support (listing); EVA case included; wall charger not included
GOOLOO GP4000: fits and best for
The big-engine value pick: gas engines of any size on its maker rating, diesels to 10.0 litres, and households that would rather have the case included than a screen. It is the finder’s answer past 12.0 litres of gas, the only band where its all-gas rating outranks the flagship. Storage care follows the listing-versus-manual disagreement printed in its cons: recharge somewhere between every 2 and 6 months, a routine our trickle charger guide covers for the vehicle battery at the other end of the clamps.
GOOLOO GP4000 pros and watch-outs
Pros
- All-gas maker rating — unique in this comparison
- Diesel rating matches the flagship: 10.0L
- EVA storage case included in the box
- 18-month warranty with lifetime tech support named
- 15V/10A DC port for 12V accessories
Watch-outs
- No screen and no fast-charge headline: 15W-class USB-C input
- Capacity and weight both conflict across sources (printed above)
- Wall charger not included
- Starts per charge not published by the maker
- Recharge interval advice conflicts: listing says every 2-3 months, the manual every 3-6 months
GOOLOO GP4000: what owners report
GOOLOO’s value line owns the warmest owner themes in the pools. BobIsTheOilGuy owners report repeated successful starts up to a 5.7-litre Hemi Ram and a habit of rescuing stranded drivers, while the same thread warns that an old, big diesel in a hard winter is where the largest packs earn their place — a fair boundary for a 10.0-litre diesel rating.
AutoGuide keeps a GOOLOO pack as its garage’s most-used unit, praising clamps that open as wide as the premium brands’ while criticising the flashlight control and the small carry bag — the GP4000’s included EVA case answers the bag point, at least. Model-specific GP4000 threads are thinner than the brand-level record, and we say so rather than dressing brand themes up as model proof.
GOOLOO GP4000: who should not buy
Skip it if a status screen and the fastest recharge are worth a flagship step to you, or if an unpublished starts-per-charge figure bothers you. Inside this comparison, the covered upgrade is the GOOLOO GT4000S; the budget step down is the AVAPOW A28 below.
GOOLOO GP4000: pair it with
Pair it with Energizer jumper cables, 16-foot and 6-gauge: the pack covers your own car, and the cables cover the day a stranger’s car — or your own flat pack — needs a donor vehicle instead.
We may earn a commission at no cost to you. Listing shown for the GOOLOO GP4000, ASIN B09HJH1S41 — an orange variant circulates under a different ASIN; confirm the model name matches.
Recharge it on the manual’s slower schedule at most — every 3 to 6 months — and sooner after any use; our battery drain guide explains the slow losses that make shelf habits matter.
Best AVAPOW Diesel Value: AVAPOW A28
AVAPOW value pick
Why the AVAPOW A28 is our pick
The A28’s whole case is one number pair: 8.0 litres of gas and 8.0 litres of diesel, from the lightest and simplest pack in this comparison. Matching its diesel rating to its gas rating is exactly what diesel owners ask for and what most value packs will not print. Around that pair sit up to 50 starts per charge on its listing, a force-start mode for fully flat batteries, a 12V/10A DC output and clamp protections that beep and flash before you make a bad connection. Its paperwork is the thinnest of the four — no IP rating, conflicting secondary figures — and the block prices that in honestly.
AVAPOW A28 key specs
- Part number: A28
- Peak current: 3,000A (maker claim; EC5 output 12V/3,000A max)
- Engine ratings: gas up to 8.0L, diesel up to 8.0L (maker)
- Jump starts per charge: up to 50 (Amazon listing; a retailer page prints 60 — conflict)
- Capacity: 23,800mAh (Amazon technical details; a retailer 59.2Wh figure does not reconcile — conflict)
- USB outputs: QC3.0 (5V/3A, 9V/2A, 12V/1.5A) + 5V/2.1A
- Charging input: Type-C 5V/3A, 9V/2A, 12V/1.5A; DC output 12V/10A
- Working temperature: -10°C to +60°C (listing spec table)
- LED: 21-bulb, 3 modes (lumens not published)
- Sealing: dustproof, shock-resistant shell — no IP rating published
- Weight: 3.3 lb; 7.87 x 3.93 x 1.57 in
- Warranty: 2 years (listing-stated via retailer reproductions)
AVAPOW A28: fits and best for
The diesel-first value pick: a diesel pickup or SUV to 8.0 litres, a V8 car to the same figure, and two-vehicle households that want one honest pack to cover both. It also appears in our budget guide at its price tier, and it is the AVAPOW half of our NOCO vs AVAPOW sibling head-to-head. Keep its warmer cold floor in mind: at -10°C it is the pack most likely in this comparison to want a night indoors.
AVAPOW A28 pros and watch-outs
Pros
- Diesel rating matches its gas rating: 8.0L of both
- Up to 50 starts per charge on the listing
- Force-start mode for fully flat batteries (3-second long-press)
- 12V/10A DC output at a value tier
- 8 clamp protections with a beep and flashing-light alert
Watch-outs
- No IP rating published — the shell claim is a description, not a test
- Warmest cold floor here: -10°C working minimum
- Starts and watt-hour figures conflict between sources (printed above)
- Warranty reaches us via reproductions, not item details
- Long-term owner coverage is thin (stated below, not padded)
AVAPOW A28: what owners report
Long-term owner coverage for the A28 is thin, and we print that plainly instead of borrowing themes from other AVAPOW models: no forum thread of real depth surfaced in the verified pools. The listing-level themes that recur centre on the force-start mode rescuing fully flat batteries and on the clamp alert system warning before a reversed connection — read them where they live, on the A28 Amazon owner listing.
The general winter doctrine for lithium packs of this class comes from owners of a rival compact in the Bogleheads booster thread: effectiveness falls as temperature drops, and some households store the pack indoors in winter. That is storage advice for the whole category, labelled as such — not an A28 test result.
AVAPOW A28: who should not buy
Skip it if your diesel runs past 8.0 litres, if you need a published IP rating, or if the coldest mornings are your use case. Inside this comparison, the covered AVAPOW upgrade is the AVAPOW A37, rated to 10.0 litres of both fuels with an IP65 shell.
AVAPOW A28: pair it with
Pair it with a NOCO GENIUS5 maintainer on the diesel itself: glow-plug batteries die slowly in vehicles that sit, and a maintained battery turns the A28 back into an emergency tool instead of a weekly one.
We may earn a commission at no cost to you. Listing shown for the AVAPOW A28, ASIN B08NPHZV8N — confirm the model on the listing; AVAPOW sells higher-output lines under other model names.
Recharge after every use and monthly through winter: a value pack stored flat is just weight in the trunk. Our battery runtime guide walks through the reserve maths behind that habit.
Best AVAPOW Overall: AVAPOW A37
AVAPOW flagship pick
Why the AVAPOW A37 is our pick
The A37 is AVAPOW’s direct answer to the GT4000S, and on published figures it lands real blows: 10.0-litre ratings for both gas and diesel, up to 60 starts per charge, an IP65 shell the A28 never claims, and 60-watt two-way PD charging through a single Type-C port that also feeds two Quick Charge outputs. What it does not publish is just as telling — no capacity figure and no model-specific warranty term appeared in the sources we verified, and both absences are printed in its spec list. Judge it as the strongest AVAPOW file here, with two pages deliberately left blank by its maker.
AVAPOW A37 key specs
- Part number: A37
- Peak current: 4,000A (maker claim; EC5 output 12V/4,000A max)
- Engine ratings: gas up to 10.0L, diesel up to 10.0L (maker)
- Jump starts per charge: up to 60 (listing)
- Capacity: Not published in the sources verified
- Charging input: Type-C PD 60W in/out (5V-20V, 3A steps); full charge about 2 hours on PD 60W
- USB outputs: 2 x QC3.0 (5V/3A, 9V/2A, 12V/1.5A each)
- LED: 21-bulb, 3 modes (flashlight, strobe, SOS); 1W per spec table
- Housing: IP65 waterproof and dustproof (listing); working -20°C to +60°C
- Protections: 8 clamp protections incl. spark-proof, with beep and flashing-light alert
- Weight: 3.21 lb; 8.07 x 4.13 x 2.13 in
- Warranty: Not published (model-specific term not isolated in sources verified)
AVAPOW A37: fits and best for
The AVAPOW flagship buyer: diesels and V8s to 10.0 litres, drivers who want one Type-C cable to charge the pack and everything else, and anyone who rates a published IP65 shell over a status screen. Cold-climate drivers in our emergency guide will note its -20°C floor matches the GOOLOO flagship’s, the widest cold margin on the AVAPOW side. It is also the comparison’s lightest full-size pack at 3.21 lb on the listing’s own figures.
AVAPOW A37 pros and watch-outs
Pros
- 10.0L ratings for both fuels — the widest AVAPOW coverage here
- IP65 shell, published rather than described
- 60W two-way PD charging through one Type-C port
- Up to 60 starts per charge on the listing
- Cold floor matches the flagship GOOLOO: -20°C
Watch-outs
- Capacity not published in the sources verified
- Warranty term not published — the weakest paper of the four
- No status screen: charge state comes from lights, not numbers
- No DC accessory output in its published spec table
- Long-term owner coverage is thin (stated below, not padded)
AVAPOW A37: what owners report
Owner coverage for the A37 is listing-level rather than forum-deep, and we say so in the open: the verified pools hold no long-term thread for this model, so its themes here are the ones its own buyers repeat on the A37 Amazon owner listing — the PD fast charging, the clamp alert system and the sealed shell. We do not dress those up as years of field history.
For the category context an AVAPOW buyer is stepping into, AutoGuide makes the reserve point that matters at this size: a garage’s most-used pack is the one with starts to spare, which is the A37’s up-to-60 claim’s real test. Treat the claim as a maker figure until your own winters grade it.
AVAPOW A37: who should not buy
Skip it if unpublished capacity and warranty figures are a deal-breaker for you — they are a fair one. Inside this comparison, the documented flagship is the GOOLOO GT4000S, whose conflicts are at least printed where you can read them.
AVAPOW A37: pair it with
Pair it with Energizer jumper cables, 16-foot and 6-gauge: a sealed, fast pack plus a set of cables that never self-discharge is the two-layer kit we recommend at every tier of this category.
We may earn a commission at no cost to you. Listing shown for the AVAPOW A37, ASIN B08T5V2BGD — confirm the model number A37 in the item details before ordering.
One cable, kept with the pack: its Type-C port is its only fast input, so the cable’s home matters. The rest of the kit belongs together too — see our recovery kit guide for how we organise vehicle emergency gear.
Spec comparison
Every figure is the maker’s published figure for the exact ASIN here. Where a maker publishes nothing, the cell says so; where sources conflict, the conflict is printed in the cell.
| Spec | GOOLOO GT4000S | GOOLOO GP4000 | AVAPOW A28 | AVAPOW A37 |
|---|---|---|---|---|
| Part number | GT4000S | GP4000 | A28 | A37 |
| Peak current (maker claim) | 4,000A | 4,000A | 3,000A | 4,000A |
| Gas rating | Up to 12.0L | All gas engines | Up to 8.0L | Up to 10.0L |
| Diesel rating | Up to 10.0L | Up to 10.0L | Up to 8.0L | Up to 10.0L |
| Starts per charge | Up to 60 | Not published | Up to 50 (retailer prints 60) | Up to 60 |
| Capacity | Conflict: 20,000 vs 24,000mAh | Conflict: 24,000 vs 26,800mAh | 23,800mAh (Wh conflicted) | Not published |
| Fastest charging in | USB-C PD 100W | USB-C (15W input per chart) | Type-C up to 12V/1.5A | USB-C PD 60W |
| USB output | QC3.0 18W + 5V/2.4A | Quick Charge 18W | QC3.0 + 5V/2.1A | 2 x QC3.0 |
| DC output | 15V/10A | 15V/10A | 12V/10A | Not published |
| Display | 3.2-inch screen | Not published | Not published | Not published |
| LED | 400 lumens | 3 modes (lumens not published) | 21-bulb, 3 modes (lumens not published) | 21-bulb, 3 modes, 1W |
| Operating range | -20°C to +60°C | -4°F to 140°F | -10°C to +60°C | -20°C to +60°C |
| Sealing | IP65 | Not published | No IP rating published | IP65 |
| Weight | Conflict: 2.31 vs about 4.9 lb | Conflict: 3.41 vs 3.94 lb | 3.3 lb | 3.21 lb |
| Warranty | 18 months (2 years claimed elsewhere) | 18 months + lifetime tech support | 2 years (listing-stated) | Not published |
| Check Price | Check Price | Check Price | Check Price | Check Price |
Using and jump-starting basics
All four packs follow the same safe sequence, and all four protect the driver following it: smart clamps with reverse-polarity and spark protection across both lines, beep-and-flash alerts on the AVAPOW pair, and a status screen on the GT4000S. Connect positive to the dead battery’s positive terminal first, then negative to an unpainted engine ground away from the battery, then switch the pack on and crank in short attempts, resting between them so the pack and the starter both stay cool.
If the clamps cannot detect the battery because it is fully flat, use the maker’s bypass — the BOOST function on the GOOLOO smart clamps, the force-start long-press on the AVAPOW pair — and stay clear of the cables while you crank, because bypass modes remove the detection that normally protects you. Once the engine runs, remove the clamps in reverse order, drive long enough to recharge the vehicle battery, and recharge the pack the same day. A battery that keeps needing jumps has a cause — a drain, an alternator or end of life — and the diagnostic habit is the same one our amp draw guide and battery drain guide teach for winch batteries.
Between emergencies, storage decides whether any of these packs works in January: top-ups on the schedule each block prints, indoor storage in deep cold and summer heat alike, and a maintainer on a vehicle that sits, as our trickle charger guide sets out. The wider routine lives in our maintenance checklist.
Safety essentials
Six rules that outrank either brand in this comparison:
- 1. Connect positive first and put the negative clamp on an engine ground away from the battery — the last connection is where a spark can happen, and it should never happen at the battery.
- 2. Use BOOST and force-start modes only for genuinely flat batteries: they bypass the detection that protects you the rest of the time, so connect carefully and stand clear while cranking.
- 3. Respect both makers’ temperature limits: charge indoors in deep winter, keep lithium packs out of a hot parked car in summer, and let a cold-soaked pack warm before asking it to crank.
- 4. A swollen, cracked or hissing pack is finished: stop using it, do not charge it, and recycle it as hazardous waste.
- 5. Recharge the pack after every use and top it up on its maker’s schedule in storage; a flat pack beside a flat battery is the failure this guide exists to prevent.
- 6. A jump start is a reprieve, not a repair: test the battery and charging system, because a repeated need means a drain, an alternator or a battery at end of life.
Three companions from this site’s verified pool pair with any pack in this comparison; the full kit list lives in our accessories hub:
NOCO GENIUS5 battery maintainer — a 5A smart charger and maintainer for the vehicle battery itself, so whichever pack you buy stays an emergency tool instead of a weekly routine.
Energizer jumper cables, 16-foot 6-gauge — the donor-vehicle backup for the day the pack is flat too; cables never self-discharge on the shelf.
NOCO GBC013 EVA protection case — made for the NOCO GB20 and GB40 compacts: it does not fit any pick in this article, and we list it only for households whose second pack is one of those NOCO compacts (see our NOCO vs Hulkman comparison for that side of the garage). The GOOLOO GP4000 already ships with its own EVA case.
Round the kit out from our essential accessories guide and keep it protected under a cover from our winch cover guide when the truck lives outside, rather than assembling any of it at the roadside.
Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| Pack beeps, flashes or shows a clamp error and will not crank | Reverse polarity or a short detected by the smart clamps | Remove both clamps, confirm positive-to-positive, reconnect positive first and negative to an engine ground |
| Clamps connected, nothing detected at all | Battery too flat for automatic detection | Use the maker bypass: GOOLOO BOOST function or the AVAPOW force-start long-press, then crank promptly and stand clear |
| Engine cranks slowly once, then stops | Pack charge low or clamps seated on corroded terminals | Clean the terminals, recharge the pack fully, retry in short cranks with rests between attempts |
| Pack was fine in autumn, weak in January | Cold-soaked lithium plus months of storage self-discharge | Warm the pack indoors, top it up, and store it inside through deep winter |
| Starts today, dead again tomorrow | Vehicle battery at end of life, a parasitic drain or an alternator fault | Test the battery and charging system; a jump pack is a reprieve, not a repair |
| Pack will not recharge | Wrong input class (the GT4000S wants its 100W-class input for its fastest rate) or a pack left flat for months | Use the maker-spec cable and input for your model; replace a pack that still refuses — never force a charge into a damaged pack |
Who should NOT buy these
Your diesel is bigger than 10.0 litres. No maker in this comparison rates a pack there, and an out-of-rating start is a hope, not a plan. AVAPOW sells a higher-rated line above the A37 that we checked but could not verify deeply enough to recommend here; the larger packs in our pillar guide are the honest route today.
You run a shop, a yard or a roadside service. Four lithium packs are still glovebox-class tools, not a repeated-starts workstation. A lead-acid box with a large reserve battery, kept on its charger, is the category built for your day — it is covered in the pillar guide.
You want one tool that also inflates tyres. No pick here has a compressor. The GOOLOO pair and the A28 can power a separate inflator from their DC ports, which we prefer to a combo unit; the combo type is compared in our jump starter comparisons archive.
You need every figure in writing before you buy. Then this comparison’s honest answer is that neither brand fully satisfies you: GOOLOO contradicts itself on capacity and weight, and AVAPOW leaves the A37’s capacity and warranty unpublished. The most documented packs in this category sit in our pillar guide, and choosing them over either brand here is a defensible call.
You will never recharge anything. All four packs are lithium tools with storage habits. If the top-up routine will not happen, a maintained vehicle battery plus cables (Block 17) is the more honest kit for you.
Final verdict
Best overall — GOOLOO GT4000S: the widest gas rating, the fastest recharge, a screen and IP65. Check its price.
Best GOOLOO value — GOOLOO GP4000: all-gas coverage and the flagship’s diesel rating, case included. Check its price.
Best AVAPOW diesel value — AVAPOW A28: 8.0L ratings for both fuels and a force-start mode at the value tier. Check its price.
Best AVAPOW overall — AVAPOW A37: 10.0L ratings for both fuels, IP65 and 60W PD charging. Check its price.
Diesel beyond every rating here: step up to the larger packs in our pillar guide to the best portable jump starter rather than stretching any of these four past its maker rating.
FAQ
GOOLOO vs AVAPOW: which brand is better?
GOOLOO is the feature brand in this comparison: its GT4000S carries the widest gas rating, the fastest recharge, a status screen and a DC port across both its picks. AVAPOW is the value brand: its A28 matches its diesel rating to its gas rating at 8.0 litres, and its A37 answers the GOOLOO flagship with 10.0-litre dual ratings and an IP65 shell. Neither brand documents itself perfectly, so the better brand is the one whose published ratings cover your engine with paperwork you accept.
Is a 4,000A GOOLOO stronger than a 4,000A AVAPOW?
The badges match and prove little, because peak-amp claims carry no shared test standard between brands. The usable difference sits in the makers’ own engine ratings: GOOLOO rates the GT4000S to 12.0L gas and the GP4000 to all gas engines, while AVAPOW rates the A37 to 10.0L of both fuels. On diesel all three stop at 10.0 litres. Route on those litre figures, never on the amp headline.
Which brand is better for a diesel truck?
It depends on the diesel. Up to 8.0 litres, the AVAPOW A28 is the value answer, with a diesel rating that matches its gas rating. From 8.0 to 10.0 litres, three picks are rated: the GT4000S, the GP4000 and the A37. Beyond 10.0 litres, no pack in this comparison is rated, and we say so in the finder instead of stretching one. Diesel cranking is the hardest work a pack does, so the rating is the decision.
Why do the GOOLOO capacity and weight figures conflict?
Because GOOLOO’s own records disagree. The GT4000S appears at 20,000mAh in one Amazon item-details record and 24,000mAh in its product information, and its weight at both 2.31 lb and about 4.9 lb across listing variants and spec reproductions. The GP4000 conflicts the same way. We print the conflicts in each spec list rather than choosing the flattering figure, and we advise planning around the heavier weight and the lower capacity.
Which pack charges fastest?
The GOOLOO GT4000S, on maker figures: 100W two-way USB-C, a full charge in about 1.2 hours, and a claimed 5-minute charge enough for a start. The AVAPOW A37 follows with 60W PD and a roughly 2-hour full charge. The GP4000 and A28 charge over 15W-class and 12V-class Type-C inputs respectively, so both are overnight packs by comparison. Recharge speed decides whether a pack is ready for the second failure, not just the first.
Can these packs start a completely flat battery?
Yes — all four makers build for that case, because smart clamps cannot detect a battery below their threshold. GOOLOO answers with the BOOST function on its smart clamps; AVAPOW gives its packs force-start modes, the A28’s on a 3-second long-press. Bypass modes remove the detection that normally protects you, so connect carefully, confirm polarity twice and stand clear of the cables while you crank.
Is the AVAPOW A37 waterproof?
Its listing publishes an IP65 waterproof and dustproof rating, which is a test standard rather than a description — the strongest sealing evidence on the AVAPOW side, matched on the GOOLOO side by the GT4000S’s IP65 housing. The A28 publishes no IP rating at all: AVAPOW describes a dustproof, shock-resistant shell, and our tables print exactly that distinction. If the pack will live somewhere wet, buy the rated shell.
What is the AVAPOW A68, and why is it not a pick?
The A68 is AVAPOW’s higher-output line: its listing claims 6,000 peak amps, all gas engines and diesels to 12.0 litres. We checked it fresh for this comparison, but its starts per charge, capacity and warranty term were not published in the sources we could verify, so a full, honest product block could not be written for it. It is named here so diesel owners past 10.0 litres know the line exists — without a recommendation we cannot stand behind.
Which has the better warranty, GOOLOO or AVAPOW?
GOOLOO’s evidence is stronger and AVAPOW’s headline is longer. GOOLOO prints 18 months on both picks in listing data, with lifetime tech support named on the GP4000, though one marketplace list claims 2 years for the GT4000S. AVAPOW’s A28 carries a 2-year term that reaches us through retailer reproductions, and the A37’s model-specific term was not published in the sources we verified. Weight the paper you can point to, not just the longest number.
How often should I recharge a GOOLOO or AVAPOW pack?
After every use, without exception, and on a storage schedule between uses. Even the makers disagree on the interval: the GP4000’s listing advises every 2 to 3 months while its manual says every 3 to 6 months, and we print both. The safe habit that satisfies either instruction is a top-up every 2 to 3 months and a recharge the same day the pack earns its keep. A pack stored flat is the most common reason any brand fails in winter.
Sources & changelog
Manufacturer and listing sources, and the owner sources paraphrased above:
- GOOLOO GT4000S — Amazon listing and item details: ratings, ports, conflicts (GOOLOO)
- GOOLOO GT4000S product page: engine ratings and charging claims (GOOLOO)
- GOOLOO GP4000 — Amazon listing: all-gas rating, warranty, case (GOOLOO)
- AVAPOW A28 — Amazon listing and technical details: ratings, capacity, ports (AVAPOW)
- AVAPOW A37 — Amazon listing, spec table and item details: ratings, PD charging, IP65 (AVAPOW)
- NOCO GENIUS5 maintainer — Amazon listing (NOCO)
- Energizer jumper cables ENB-616U — Amazon listing (Energizer)
- NOCO GBC013 case — Amazon listing: fits GB20 and GB40 (NOCO)
- AVAPOW A68 retailer spec record — checked and excluded: unverified starts, capacity and warranty (see FAQ)
- AVAPOW A37A/AP6 manual record via manuals.plus — BOOST and charging troubleshooting doctrine (A37A variant, not used for A37 specs)
- AR15.com — owners: GOOLOO storage behaviour and rival-brand comparison
- BobIsTheOilGuy — owners: GOOLOO starts on large gas engines, winter diesel caution
- AutoGuide — garage notes: GOOLOO as most-used pack, clamp praise
- Bogleheads — owners: lithium-pack cold behaviour and indoor winter storage (category doctrine)
Changelog — October 17, 2026: guide first published.
By Leo, Founder, WinchInsider
Leo founded WinchInsider to publish specification-first truck and recovery guides: every figure from the maker, every conflict printed, and no product recommended for a job its maker does not claim it can do. More about the site is on our about page.
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