Head-to-head test
EcoFlow RIVER 2 Max vs Jackery Explorer 500
The RIVER 2 Max and Explorer 500 share almost every spec on paper — capacity, output, weight — except the one that decides how long either lasts: 3,000-cycle LFP chemistry against 500-cycle lithium-ion, which turns a $60 price gap into a sevenfold gap in cost per lifetime kWh.
Written by Wenny ZhengUpdated
Portable Power Tester, Station Arena Test Desk
EcoFlow
RIVER 2 Max
2,030Power Score · Appliance Class
$289.00 list · direct from EcoFlow
Jackery
Explorer 500
1,473Power Score · Device Hub
$359.00 list · direct from Jackery
Spec deltas
The EcoFlow RIVER 2 Max and Jackery Explorer 500 ship with almost identical numbers: 512Wh against 518Wh, 500W continuous output on both, a 1,000W surge on both, and about 13.4 lbs on both scales. Read the spec sheet alone and it looks like a coin flip.
It isn't, once you look at what's inside the case rather than what it holds. The RIVER 2 Max runs newer LFP cells rated for 3,000 charge cycles; the Explorer 500 runs older lithium-ion cells rated for 500. That single difference is why the RIVER 2 Max costs $60 less up front and still works out to a fraction of the lifetime cost.
The Explorer 500 isn't without an argument — it's the quieter of the two by a wide margin, which matters for exactly one buyer on this page. Everyone else should let cycle life decide it.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
rated cycles
Run that over a full service life and the gap stops looking like $60: the RIVER 2 Max lands at $0.19 per lifetime kWh, the Explorer 500 at $1.39. The cheaper sticker is riding on top of a battery that also outlasts the pricier one by a wide margin.
RIVER 2 Max: $299, 512Wh, rated for 3,000 cyclesExplorer 500: $359, 518Wh, rated for 500 cycles
Why it mattersAnyone comparing these two on sticker price alone is reading the wrong number — look at cost per warranty-year or cycle count instead.
That combination means it can't double as a silent UPS for a router or desktop during a blackout the way the RIVER 2 Max can, and it can't fast-charge a modern laptop or phone off a single cable either — everything routes through an AC outlet and a wall wart instead.
RIVER 2 Max includes UPS protection with a 30-millisecond switchoverExplorer 500 has no listed switchover spec and ships with 0W of USB-C output
Why it mattersBuyers who want one box to protect a modem through a power flicker, not just run a cooler at a campsite, should rule out the Explorer 500 on this alone.
37dB sits near a quiet library; 62dB sits closer to a dishwasher running two rooms away. For every other use case on this page the RIVER 2 Max wins on cost and longevity, but a CPAP buyer sensitive to fan noise has a real, spec-true reason to take the quieter Jackery anyway.
Explorer 500 is rated at 37dB, RIVER 2 Max at 62dBBoth cover CPAP Overnight comfortably — 74% and 73% of capacity respectively
Why it mattersCPAP buyers should weigh noise over lifetime cost here; everyone else should weigh lifetime cost over noise.
solar input
In a multi-day outage where the wall isn't an option, that gap compounds daily — the RIVER 2 Max can squeeze a second full solar refill into the same string of daylight hours the Explorer 500 needs just to finish its first.
RIVER 2 Max accepts up to 220W of solar inputExplorer 500 accepts up to 100W and is rated at about 7.4 hours for a full solar recharge
Why it mattersOff-grid or multi-day outage buyers should weight solar refill speed heavily toward the RIVER 2 Max.
The specific dimensions that decide these two units — everything else is a tie.
Lifetime Value
Selected because: Near-identical sticker prices hide a sevenfold gap in cost per lifetime kWh — the real decision driver.
cost / lifetime kWh
Run both units over a full service life and the RIVER 2 Max costs $0.19 per lifetime kWh against the Explorer 500's $1.39 — a gap that has nothing to do with the $60 sticker difference and everything to do with cycle count. Cost per warranty-year tells the same story from another angle: $60 a year for the RIVER 2 Max, $180 for the Explorer 500.
At daily use, the RIVER 2 Max is rated to run for 8.2 years before its cycle count is spent; the Explorer 500, on the same schedule, is rated for 1.4. That's not a rounding difference — it's most of the practical service life of the pricier unit, compressed into under a year and a half.
What the Specs Don't Tell You
Selected because: UPS switchover, zero USB-C, and the noise gap are concrete, spec-true differentiators between two similar-looking units.
rated cycles
The RIVER 2 Max is the noisier of the two under load — 62dB against the Explorer 500's 37dB — the price of packing a faster charger and a UPS relay into a light chassis. The Explorer 500 counters with a solar input less than half the RIVER 2 Max's 220W, which is why the engine puts its full solar recharge at about 7.4 hours.
Zero. Not fast, not slow — the Explorer 500 ships with 518Wh of battery and not one watt of USB-C output, a gap that stands out on a unit still selling today. Warranty tells the rest of the story: 5 years on the RIVER 2 Max against 2 on the Explorer 500, which is exactly why the RIVER 2 Max's cost-per-warranty-year lands at $60 against $180.
Your Life, Your Pick
Selected because: Both undersized for the big jobs; CPAP Overnight is their one genuine tie, worth breaking down.
Both units are undersized for anything past light daily use. At Van Life Daily's 4,685Wh, they'd need to be recharged and drained more than ten times over — 1,077% and 1,064% of capacity respectively. This pairing isn't about that scale of job; look elsewhere in either brand's lineup for that.
CPAP Overnight is the one job both handle solo, at 74% and 73% of their tanks — essentially a dead heat. Break that tie on economics, not capacity: the RIVER 2 Max's cycle life and warranty put it well ahead unless the Explorer 500's quieter fan is worth more to you than either.
Brand Trust
Selected because: EcoFlow's ecosystem and app lead clearly; Jackery counters with retail reach and brand recognition.
EcoFlow's ecosystem is the largest in the category and its app rates well ahead of Jackery's — 4.6 on iOS against Jackery's 2.3 to 3.3 across both platforms, described as the weakest app experience among the major brands. Jackery counters with the widest retail footprint and the strongest brand recognition of any name in this comparison — the dependable, everywhere option, if not the cutting-edge one.
Neither brand's support record is spotless. EcoFlow's is polarized between smooth prepaid-label replacements and long waits; Jackery's draws more consistent criticism for scripted responses and strict receipt requirements. Buying either from Costco or Amazon is the safety net worth taking regardless of which unit you pick.
Strengths & trade-offs
EcoFlow RIVER 2 Max
Strengths
- +Costs $70 less
- +Longer warranty
- +Faster solar charging
- +Rated for 3,000 charge cycles — much longer battery lifespan
Trade-offs
- –Can receive complaints about fan noise under heavy load.
Jackery Explorer 500
Strengths
- +Lighter by 0.1 lb
- +Larger battery capacity
Trade-offs
- –Lacks smartphone app control for remote monitoring.
- –Shorter-lived battery — rated for 500 charge cycles vs the RIVER 2 Max's 3,000, so it wears out sooner.
Will It Power Your Gear?
Scenario math and per-appliance runtimes, modeled from the spec record.
Scenario verdicts
We ran the math on six real-world scenarios. Here's which unit survives your actual life.
SCN-01 · 2 nights · needs 2,100Wh
Weekend Camping
Two nights off-grid with essential comfort
Neither unit
Neither unit can fully handle this scenario (needs 2,100Wh). You'd need a higher-capacity station or to cut back on usage.
Battery budget usedlower = more headroom
LOAD Phone Charger 15W×6h · LED Lights 40W×8h · Box Fan 75W×14h · CPAP Machine 40W×16h
SCN-02 · 8 hours · needs 1,645Wh
8-Hour Blackout
Keep the essentials running through a night without power
Neither unit
Neither unit can fully handle this scenario (needs 1,645Wh). You'd need a higher-capacity station or to cut back on usage.
Battery budget usedlower = more headroom
LOAD Fridge 150W×8h · Router + Modem 20W×8h · LED Lights (4 bulbs) 40W×6h · Phone Charger 15W×3h
SCN-03 · 8 hours · needs 320Wh
CPAP Overnight
Sleep therapy without interruption — the #1 medical use case
Either unit
Both are wildly overqualified for CPAP. You're using 74% or less. Save your money and buy whichever is cheaper; the extra capacity is completely wasted on a 40W overnight load. Put the savings toward a second battery for multi-night trips.
Battery budget usedlower = more headroom
LOAD CPAP Machine 40W×8h
SCN-04 · 8 hours · needs 910Wh
Remote Workday
Full work day off-grid without power anxiety
Neither unit
Neither unit can fully handle this scenario (needs 910Wh). You'd need a higher-capacity station or to cut back on usage.
Battery budget usedlower = more headroom
LOAD Laptop 60W×8h · External Monitor 30W×8h · Router + Modem 20W×8h · Phone Charger 15W×2h
SCN-05 · 4 hours · needs 670Wh
Tailgate Party
Game day power for the crew
Neither unit
Neither unit can fully handle this scenario (needs 670Wh). You'd need a higher-capacity station or to cut back on usage.
Battery budget usedlower = more headroom
LOAD Blender 400W×0.5h · LED TV (55") 80W×4h · Bluetooth Speaker 15W×4h · Phone Charger (×3) 45W×2h
SCN-06 · 24 hours · needs 4,685Wh
Van Life Daily
A full day of mobile living — the ultimate endurance test
Neither unit
Neither unit can fully handle this scenario (needs 4,685Wh). You'd need a higher-capacity station or to cut back on usage.
Battery budget usedlower = more headroom
LOAD Mini-Fridge 150W×24h · Laptop 60W×4h · Phone Charger 15W×3h · LED Lights 40W×5h · Fan 75W×8h
The Load Test
RUNTIME = (Wh × 0.85) ÷ LOAD
None of the six scenarios above exactly yours? Build it. Toggle what you'd plug in; both units are tested against the combined draw.
Essentials
Comfort & Convenience
High-Draw Appliances
Test duration
8h
Continuous draw
205W
Projected runtime
Dead heat — both run this 205W load for roughly 2.1h. Pick on price, weight, or ports.
Modeled from the spec record — same math as the tables below. Methodology
Runtime by appliance
Real-world runtime estimates for common appliances, modeled at 85% inverter efficiency.¹
Essentials
The basics you need runningscale 0–29.4hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–5.9hHigh-Draw Appliances
These reveal the real limits¹ Runtime = (capacity × 0.85) ÷ appliance watts. Within each group, all bars share one time scale (the group's longest runtime), so lengths are comparable across appliances; identical runtimes collapse into a single blue/orange bar. Actual runtime varies with battery age, temperature, and simultaneous loads — see methodology.
Conclusion
July 14, 2026
Verdict: the RIVER 2 Max, on Power Score margin
The RIVER 2 Max wins on every number that compounds over ownership: $0.19 per lifetime kWh against the Explorer 500's $1.39, a 3,000-cycle LFP battery against 500-cycle lithium-ion, a 5-year warranty against 2, and 30-millisecond UPS switchover the Explorer 500 doesn't offer at all. The Explorer 500's one genuine edge — 37dB against 62dB under load — only outweighs that if fan noise a few feet from you overnight is the deciding factor, which for a CPAP buyer it legitimately can be.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of July 14, 2026. The links below open EcoFlow's and Jackery's current prices.
$289.00 list · direct from EcoFlow
or check the Explorer 500 price$359.00 list
Written by Wenny Zheng, Portable Power Tester · Station Arena Test Desk · Updated July 14, 2026
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
Not rated for both units (minimum threshold unmet): CPAP, Solar Generator, Tailgating.
Full specifications
ᵈ Derived: price ÷ rated capacity. See the data behind our comparisons →
Comparison ToolAdd more power stations, side by sideOpen Tool →How these numbers are produced
Numeric verification
Every figure on this page traces to our spec database or arithmetic on it — no estimated numbers.
Owner claims
Statements about owner experience are cited to published reviews — see Sources & Research Notes below.
Runtime model
Runtime = (rated capacity × 0.85 inverter efficiency) ÷ device wattage. Solar recharge estimates assume panels deliver 70% of rated output. Cold weather, battery age, and stacked loads reduce real-world results.
Power Score
Computed from 14 published spec dimensions, weighted per use-case bench. Higher is better; a unit must meet a bench's minimum threshold to be rated.
See the full weight table and data sourcing on our methodology page →Class ranking (the star rating)
Each unit's star score is a category ranking, not customer reviews — no buyer opinions feed it. We score every station on size-independent quality (value, output, portability, endurance, ports, warranty, and more), then percentile-rank it against the other units in its capacity class, so a class-leading compact unit and a class-leading whole-home unit can both earn 5★. Here, RIVER 2 Max rates 3.9/5 (33rd percentile of 19 Compact-class units), and Explorer 500 rates 3.3/5 (1st percentile of 19 Compact-class units).
How the class ranking is computed →Test Notes & Caveats
Hidden gotchas and advantages we spotted that you won't find on the product page.
RIVER 2 Max: 62dB Under Load
62dB is about as loud as a normal conversation. If you're running a CPAP or sleeping near this unit, the fan noise may be noticeable. Most people find anything above 45dB disruptive for sleep.
Explorer 500: Solar Recharge Takes 7.4h
At 100W max solar input (realistically ~70W in good conditions), recharging the full 518Wh takes roughly 7.4 hours of direct sun. Not practical for daily off-grid use. You'll need a wall outlet or generator for regular recharging.
Explorer 500: No App Control
Without app control, you have to physically walk to the Explorer 500 to check battery level, adjust settings, or monitor power draw. The RIVER 2 Max lets you do all that from your phone, including getting low-battery alerts.
Only the RIVER 2 Max Has UPS Protection
The RIVER 2 Max can act as an uninterruptible power supply. Plug your PC, router, or CPAP into it and it switches to battery seamlessly during an outage. The Explorer 500 doesn't have this feature, so connected devices will experience a power interruption.
Warranty Value Comparison
The RIVER 2 Max gives you 17.3 years of warranty per $1,000 spent, vs the Explorer 500's 5.6 years. That's 3.1× more coverage per dollar. An underrated factor if you're keeping this unit for years.
Battery Lifespan in Real Years
The RIVER 2 Max is rated for 3,000 cycles vs 500. In real life: at daily use, that's 8.2 vs 1.4 years. At weekend use (twice a week), it's 29 vs 5 years. After hitting the cycle limit, the battery doesn't die. It drops to ~80% original capacity, which is still very usable.
Full record above — the Test Desk pick is the RIVER 2 Max.
Check RIVER 2 Max price →or check the Explorer 500 priceOwnership Analysis
What happens after you buy — true cost of ownership, brand trust, and growth potential.
Lifetime value
Service lifeyears at one full cycle per day
Lifetime energy delivered
Cost per delivered kWh
│ warranty ends · Reaching the cycle rating means ~80% capacity remains — degraded, not dead.
Analyst note
The RIVER 2 Max wins on both sticker price and long-term value. At $0.19/kWh over its lifetime, it's meaningfully cheaper to own. Clear value winner.
Delivers each lifetime kWh for $1.20 less — check the RIVER 2 Max price →
Brand trust
EcoFlow
Ecosystem
Largest in portable power — 12-15 models across DELTA Pro, DELTA 3, and RIVER 3 series, plus solar panels and smart home panels
Support
US-based phone/email/chat support (1-800-368-8604). Experiences are polarized — many report hassle-free prepaid-label replacements, but others report long waits and refurbished units sent for new claims. Pro tip: buying from Costco or Amazon gives you a stronger return safety net.
Community
Largest community in the space — Reddit r/Ecoflow_community (~31K members), multiple Facebook groups, and an official community forum
App experience
Rated 4.6/5 iOS (~8,400 ratings) · 4.2/5 Android (~17,000 ratings)
Unique strength
Fastest-charging technology (X-Stream), deepest product ecosystem, and most active innovation cadence. Supports up to 180kWh modular expansion with DELTA Pro Ultra X.
Worth knowing
The Oct 2025 DELTA Max 2000 recall (overheating/fire risk, 6 incidents) is worth noting. Also tested subscription paywalls for advanced app features in early 2025 before community backlash paused the plan. No parts or service offered out of warranty.
Jackery
Ecosystem
12-15+ models across Explorer (portable) and HomePower (home backup) series, plus SolarSaga panel ecosystem and innovative form factors
Support
US-based support but widely criticized. Reddit reports describe slow/dismissive responses, scripted AI agents, strict receipt requirements for warranty claims, and refurbished replacements for clearly defective units. Strongly recommended: buy from Costco or Amazon for return protection.
Community
Smallest community of the major brands — Reddit r/Jackery has ~2,000 members. YouTube presence is solid due to brand recognition.
App experience
Rated 2.3-3.3/5 iOS and Android — the weakest app experience of the major brands. Multiple confusing apps (Jackery app vs Jackery Home) and mandatory login even offline.
Unique strength
Highest brand recognition and widest retail distribution (Costco, Home Depot, Best Buy, Amazon). The "Toyota" of power stations — dependable, proven, wide availability. Innovative form factors like the Solar Gazebo and Solar Mars Bot.
Worth knowing
A couple of older models still ship NMC chemistry with a shorter rated lifespan, so check the cycle rating on the specific unit — though most of the current line has moved to LFP. Generally perceived as overpriced for the specs offered compared to newer competitors. App experience is significantly behind rivals.
Analyst note
Pick your tradeoff, not your reputation, here. EcoFlow's ecosystem and app are bigger and better rated, but the brand carries a real recall in its recent history. Jackery's name recognition is unmatched, but its app and support lag furthest behind of the major brands. Neither company is simply the safer choice — each has one flaw worth knowing before you buy either unit.
Growth path
RIVER 2 Max
FIXED CAPACITYFixed at 512Wh, with no expansion — so size it for your needs up front rather than planning to add capacity later.
Accepts up to 220W of solar. Limited to a single portable panel.
Adequate ports for most setups, but heavy users may want a power strip.
Explorer 500
FIXED CAPACITYFixed at 518Wh, with no expansion — so size it for your needs up front rather than planning to add capacity later.
Accepts up to 100W of solar. Limited to a single portable panel.
Limited ports. You'll likely need a power strip or splitter.
Realistic full solar rechargeat 70% of rated panel output — see methodology
Analyst note
Neither expands, and that's no knock on either — each is a complete unit at a fixed size. Buy the capacity that covers your needs now (the Explorer 500 gives you the larger ceiling); you can't add to either later.
What Owners Report
Patterns from published owner reports and long-term reviews — every claim cited to its source below.
EcoFlow RIVER 2 Max
The RIVER 2 Max's upgraded LFP chemistry is rated for about 3,000 cycles — roughly a decade of daily use — and reviewers who ran it through a real event reported it powering a telescope, a 65-inch TV, two laptops, and phones through a 4-hour stretch with capacity to spareA4. It also undercuts most of its Li-ion-class rivals on weight at about 13 lbsA1.
Full-charge speed draws consistent praise: about 60 minutes via X-Stream charging, with multiple charging paths availableA2. The companion app is called out too, for straightforward remote monitoring and charge-speed control over WiFi and BluetoothA3.
“512Wh in a light package of about 13 lbs, lighter than some of its closest competitors that use Li-Ion chemistry.”
Sources
storagereview.com · backuppowerhub.com · gagadget.com · ecoflow.com · thecampingnerd.com · thetechnologyman.com · bestbuy.com
Jackery Explorer 500
Reviewers note the Explorer 500 runs on Jackery's older lithium-ion chemistry, with real capacity-retention limits compared to the newer LFP cells now standard in the categoryB1 — the follow-up Explorer 500 v2 switched to LiFePO4 specifically to fix that shorter lifespanB4. At around 13 lbs it's still praised as compact and easy to carryB2.
It's flagged as an accessible, affordable entry into Jackery's ecosystem for occasional weekend useB3 — a reasonable pick for someone who won't push it toward daily-use cycle counts.
“518Wh capacity with a 500W output, on traditional lithium-ion cells — Jackery rates 80% capacity retention after 800 cycles.”
Sources
backuppowerhub.com · jackery.com · greencitizen.com · poweredportablesolar.com · batteryessence.com
Sources & Research Notes
Every owner claim in this report is traceable to a published source. The bracketed references above resolve here.
Recurring owner themes
- Light weight, fast roughly-one-hour charging, and a simple capable app are the standout praise for this 512Wh unit. [RIVER 2 Max · 3 entries]
- Affordable, portable Jackery entry unit, but on older lithium-ion chemistry with limited cycle life vs newer LFP models. [Explorer 500 · 3 entries]
- A1
“512Wh in a light package of about 13 lbs, lighter than some of its closest competitors that use Li-Ion chemistry.”
storagereview.com / backuppowerhub.com — RIVER 2 Max review · 2026 · [positive]
- A2
“Fully charges in about 60 minutes via X-Stream charging — far faster than most portable power stations — with multiple charging options.”
gagadget.com / ecoflow.com — RIVER 2 Max review · 2026 · [positive]
- A3
“The EcoFlow app offers simple remote control and monitoring over WiFi and Bluetooth — view charge levels, customize settings, and adjust charging speed from a phone.”
thecampingnerd.com / ecoflow.com — RIVER 2 Max review · 2026 · [positive]
- A4
“Upgraded LFP chemistry rated for about 3,000 cycles, roughly a decade of everyday use; in field testing it powered a telescope, a 65-inch LED TV, two laptops, and phones through a 4-hour event with power to spare.”
thetechnologyman.com / bestbuy.com owner reviews — RIVER 2 Max · 2026 · [positive]
- B1
“518Wh capacity with a 500W output, on traditional lithium-ion cells — Jackery rates 80% capacity retention after 800 cycles.”
backuppowerhub.com / jackery.com — Explorer 500 review · 2026 · [mixed]
- B2
“Weighs about 13 lbs — a compact, portable unit.”
greencitizen.com / poweredportablesolar.com — Explorer 500 review · 2026 · [positive]
- B3
“The 518Wh capacity at $449 is the most affordable entry into Jackery's reliable ecosystem — good for weekend warriors and occasional users.”
backuppowerhub.com — Explorer 500 review · 2026 · [positive]
- B4
“An older lithium-ion unit; the newer Explorer 500 v2 uses LiFePO4 rated for far more cycles, offering significantly better longevity.”
batteryessence.com / backuppowerhub.com — Explorer 500 v2 review · 2026 · [mixed]
Research compiled July 14, 2026.
Who Should Buy Which
Buy the RIVER 2 Max if you…
- →Your actual use looks like what these test out at — a CPAP overnight, an emergency-radio kit, a router during a blackout — and you want the cheaper unit with a battery that outlasts it many times over.
- →You want UPS-style automatic switchover for a modem or desktop, which the Explorer 500 doesn't offer at all.
Buy the Explorer 500 if you…
- →Fan noise near your bed matters more to you than lifetime cost — 37dB against 62dB is the one spec where the Explorer 500 genuinely wins.
- →You're buying into Jackery's retail reach and brand recognition specifically, and you're fine treating this as a lower-cycle, shorter-term unit.
If neither fits
If your real need is anything on the scale of Weekend Camping (about 2,100Wh) or an 8-hour multi-appliance blackout (about 1,645Wh), both of these fail that job at roughly 4.8x and 3.8x their capacity. Look at a unit in the 1,500Wh-plus range instead.
The Bottom Line
The RIVER 2 Max and Explorer 500 read like the same 500W, roughly 13-lb power station on a spec sheet, but the battery inside them isn't the same product. 3,000-cycle LFP against 500-cycle lithium-ion turns a $60 price gap into a sevenfold gap in lifetime cost — $0.19 per kWh against $1.39 — before UPS protection and a longer warranty even enter the conversation.
Take the RIVER 2 Max unless a fan 25dB quieter matters more to you than any of that — which, for a unit sitting next to a CPAP machine, it legitimately might.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Is the EcoFlow RIVER 2 Max actually better than the Jackery Explorer 500, or are they the same unit?
They look identical on capacity, output, and weight, but the battery chemistry isn't the same product. The RIVER 2 Max runs 3,000-cycle LFP cells; the Explorer 500 runs 500-cycle lithium-ion. That's why the cheaper RIVER 2 Max also works out to $0.19 per lifetime kWh against $1.39 for the Explorer 500.
Why is the Jackery Explorer 500 rated for so few charge cycles?
It's built on Jackery's older lithium-ion chemistry rather than the LiFePO4 cells the RIVER 2 Max uses — a limitation Jackery addressed in the follow-up Explorer 500 v2, but the original still ships with the shorter-lived cells. That's 500 cycles against the RIVER 2 Max's 3,000.
Which one is quieter?
The Explorer 500, by a wide margin — 37dB against the RIVER 2 Max's 62dB under load. If this unit will sit a few feet from you overnight, that's the deciding spec.
Does either one work as a UPS during a power outage?
Only the RIVER 2 Max. It switches to battery power in 30 milliseconds, fast enough to keep a router or desktop running through the transition. The Explorer 500 has no listed switchover spec and isn't built for that job.
Is the RIVER 2 Max worth $60 more than the Explorer 500?
It's actually the cheaper unit — $299 against $359 — and that $60 in savings comes with 3,000-cycle LFP chemistry instead of 500-cycle lithium-ion, a 5-year warranty instead of 2, and UPS protection the Explorer 500 doesn't have. The one buyer it doesn't clearly win over is someone who needs the quietest possible fan by their bed.
Where to buy
EcoFlow RIVER 2 MaxPick
$289.00
$289.00 list · direct from EcoFlow
Jackery Explorer 500
$359.00
$359.00 list · direct from Jackery
Prices may vary by retailer and are subject to change.