Head-to-head test
BLUETTI AC500 + 2×B300K vs BLUETTI EP500Pro
The EP500Pro is sealed at 5,120Wh; the AC500 + 2×B300K starts higher at 5,530 and can grow past it. The AC500 costs $200 less, pushes 2,000W more, and is the only one of the two that finishes a full off-grid day — the EP500Pro's counter is a proven track record, not a better spec sheet.
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
BLUETTI
AC500 + 2×B300K
5,894Power Score · The AC & Fridge Zone
$3,948.00 · direct from BLUETTI
Last checked 22 days ago. Prices move — check before you buy.
BLUETTI
EP500Pro
4,956Power Score · Appliance Class
$3,499.00 · direct from BLUETTI
Last checked 6 days ago. Prices move — check before you buy.
Spec deltas
The AC500 + 2×B300K costs $200 less than the EP500Pro and outspecs it in every direction that isn't age. It holds 410Wh more, doubles it on nothing but delivers 2,000W more continuous output (5,000W vs 3,000), surges to 10,000W against 6,000, and can grow past its starting capacity where the EP500Pro is sealed shut. Same brand, same 3,500-cycle cells — one of these is just a newer, more capable machine.
The EP500Pro's whole argument is that it's been around. It's a first-generation all-in-one with a real service record: one long-term test had it working superbly after a year and a half, holding roughly half its charge after a year in storageB1B2. Its fan is quietB6 and its output is rock-solid under loadB9. If what you want is a sealed box you wheel into a corner and stop thinking about, it has earned that trust in a way the brand-new two-battery AC500 stack simply hasn't yet.
But trust doesn't close a 2,000W output gap or unseal a fixed battery. The EP500Pro tops out at 5,120Wh forever, and that ceiling is exactly what loses it the one scenario a system this size exists for: a full off-grid day. The AC500 does more today and can do more tomorrow, for less money. Unless the EP500Pro's track record is worth $200 and a chunk of capability to you, the newer stack is the pick.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
continuous output
The AC500 delivers 2,000W more output today and can grow beyond its 5,530Wh tomorrow; the EP500Pro is fixed at 3,000W and 5,120Wh for its entire life. On identical cells, that makes the AC500 the more capable machine both now and as your needs move.
AC500 runs 5,000W continuous and expands past 5,530WhEP500Pro runs 3,000W continuous and is sealed at 5,120WhBoth use the same 3,500-cycle LFP cells
Why it mattersAnyone whose loads might climb — a bigger inverter draw or more storage — should not buy the sealed unit.
Capacity
At 4,685Wh, a full van-life day lands right at the edge of usable capacity — inside the AC500's 5,530Wh, past the EP500Pro's 5,120. And because the EP500Pro is sealed, there's no expansion battery to close the gap; it simply runs out before the day does.
A full off-grid day here needs about 4,685WhAC500 covers it on 5,530Wh; EP500Pro's usable 5,120Wh comes up shortThe EP500Pro can't add a battery to make up the gap
Why it mattersFull-day off-grid users take the AC500; the EP500Pro's ceiling is a hard stop, not a soft one.
There's no axis on the spec sheet where the EP500Pro leads — it's $200 more, $0.03 per kWh more to own, and 1,236 composite points behind. Its case rests entirely off the spec sheet, on a documented service history the new stack hasn't had time to build.
AC500 is $3,299 vs EP500Pro $3,499 — $200 lessAC500 costs $0.17 per lifetime kWh vs $0.20Composite scores 6,612 vs 5,376 — a 1,236-point gap
Why it mattersIf you're deciding on numbers, it's the AC500; only a buyer paying specifically for a proven track record should hesitate.
The specific dimensions that decide these two units — everything else is a tie.
Growth Path
Selected because: Expandable vs sealed is the structural axis and the EP500Pro's hard ceiling.
solar input
This is the cleanest structural split between the two. The AC500 accepts BLUETTI expansion batteries, so its 5,530Wh is a floor you can build on; the EP500Pro is a sealed 5,120Wh and that number never changes. For a lot of buyers a fixed capacity is genuinely fine — it's one fewer connector to fail, and 5,120Wh covers most of what people ask of a home-backup unit.
The catch is that the sealed unit here is also the smaller and weaker one. If the EP500Pro started higher than the AC500, its lack of expansion would be a fair trade for simplicity. Instead it starts 410Wh lower, runs 2,000W softer, and can't grow — so the AC500 beats it on capacity today and leaves the door open for tomorrow. Sealed only wins when the sealed box is the bigger box, and it isn't.
PowerScore Breakdown
Selected because: 2,000W output gap drives the 1,236-point composite spread.
overall power score
The 1,236-point composite gap — 6,612 to 5,376 — is mostly one number: output. The AC500 inverter runs 5,000W continuous to the EP500Pro's 3,000 and surges to 10,000W against 6,000. That's not a marginal edge; it's two-thirds more running power and nearly double the surge, the room to start heavy motor loads the EP500Pro would have to sit out.
Everything else compounds the same direction. Same cells, same 3,500 cycles, but the AC500 holds more, charges from more solar (3,000W against 2,400), and expands. The EP500Pro's output is genuinely stable and clean under loadB9 — it just has less of it. On raw capability this isn't close.
Lifetime Value
Selected because: AC500 is cheaper up front and to own; the EP500Pro leads on nothing here.
The AC500 is the cheaper unit to buy and the cheaper unit to own. It's $200 less at the register, and because it holds 410Wh more on the same 3,500-cycle cells, it delivers more lifetime energy per dollar — $0.17 per lifetime kWh against the EP500Pro's $0.20. Neither stack lists a warranty on our spec sheet, so that tiebreak stays neutral.
The EP500Pro's rebuttal isn't on this table — it's the service record. A year-and-a-half-long test found it still performing like newB1, which is a real form of value the arithmetic can't score. But paying $200 more for less capacity and less output, in exchange for a longer paper trail, is a narrow trade most buyers won't want to make.
Your Life, Your Pick
Selected because: The van-life day is the one scenario the sealed EP500Pro can't finish.
Most scenarios are a tie because both units are large: an eight-hour blackout (about 1,645Wh), a remote workday (about 910Wh), a tailgate (about 670Wh) barely dent either pack. Where they split is the full off-grid day.
A van-life day here draws about 4,685Wh, and that's the line the EP500Pro can't cross. The AC500's 5,530Wh covers it — right at the edge of usable energy, but covered — while the EP500Pro's 5,120Wh runs short before the day ends and, sealed, has no way to add the capacity it's missing. For the single scenario a 5kWh stack is really bought for, the fixed unit is the one that leaves you rationing.
Strengths & trade-offs
BLUETTI AC500 + 2×B300K
Strengths
- +Larger battery capacity
- +Higher AC output
- +Faster solar charging
Trade-offs
- –Very heavy unit that may be difficult for one person to lift.
BLUETTI EP500Pro
Strengths
- +Costs $449 less
- +Lighter by 9.1 lb
Trade-offs
- –Weaker inverter (-2,000W) limits appliance compatibility.
- –Very heavy unit that may be difficult for one person to lift.
- –Sealed capacity — the AC500 + 2×B300K can add batteries to grow past 5,120Wh; this one can't.
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
Scoring these two at a campsite is a category error: the AC500 + 2×B300K at 196 lbs is not a take-along — it rolls off a truck bed if it travels at all, and the EP500Pro at 187 lbs is not a take-along — it rolls off a truck bed if it travels at all. The 2,100Wh here is trivial for either — it's the going that doesn't happen. If you need power away from the building, you're shopping the wrong class.
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
Either unit
An eight-hour outage draws about 1,645Wh — roughly a third of either pack, well within both. Capacity isn't the deciding factor at this load, so the tiebreak is the AC500's greater surge headroom for anything large that kicks on mid-outage, against the EP500Pro's edge in documented, sit-for-months-and-still-work standby reliability.
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
A CPAP is about 40W for eight hours, so both cover the night with room to spare and capacity decides nothing. Fan noise would — but AC500 + 2×B300K doesn't publish a figure, so there's nothing to hold it to. Buy on price, weight, and whether you can live with a fan you haven't heard.
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
Either unit
Both power your workstation all day without strain, and their USB-C output is a wash — pick on weight, ports, or price.
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
Scoring these two at a tailgate is a category error: the AC500 + 2×B300K at 196 lbs is not a take-along — it rolls off a truck bed if it travels at all, and the EP500Pro at 187 lbs is not a take-along — it rolls off a truck bed if it travels at all. The 670Wh here is trivial for either — it's the going that doesn't happen. If you need power away from the building, you're shopping the wrong class.
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
AC500 + 2×B300K
A full off-grid day pulls about 4,685Wh, and this is the one scenario that separates them. The AC500's 5,530Wh covers it, right at the edge of usable capacity; the EP500Pro's sealed 5,120Wh runs out before the day does, and there's no expansion battery to add. If your daily off-grid budget is this high, the fixed unit is the one that leaves you rationing by evening.
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 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
For this load: AC500 + 2×B300K runs 22.9h vs 21.2h.
$3,948 list · direct from BLUETTI
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 0–313.4hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–62.7hHigh-Draw Appliances
These reveal the real limitsscale 0–4.7h¹ 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 18, 2026
Verdict: the AC500 + 2×B300K, on Power Score margin
The AC500 + 2×B300K beats the EP500Pro on price and nearly every capability that matters. It holds 5,530Wh to the EP500Pro's fixed 5,120, runs 5,000W continuous against 3,000, surges to 10,000W against 6,000, and can add batteries where the EP500Pro is sealed for life — all for $200 less ($3,299 vs $3,499). That drops its cost-to-own to $0.17 per lifetime kWh against $0.20, and our composite scores it 6,612 to 5,376, a 1,236-point gap that's mostly the output difference. The EP500Pro is the older, sealed, all-in-one design, and its one real edge is trust: it has a documented 1.5-year field record and a notably quiet fan, where the two-battery AC500 stack has no long-term data yet and a platform with some dead-on-arrival reportsB7. Buy the EP500Pro if a proven, integrated, plug-and-forget box matters more than watts or headroom. For almost everyone else, the AC500 is more unit for less money.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of July 18, 2026. The links below open BLUETTI's current price.
$3,948.00 · direct from BLUETTI
Last checked 22 days ago. Prices move — check before you buy.
or check the EP500Pro price$3,499.00 list
Written by Gunner Gustafson, Whole-Home Backup Tester · Station Arena Test Desk · Updated July 18, 2026
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
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, AC500 + 2×B300K rates 4.1/5 (47th percentile of 16 Home Backup-class units), and EP500Pro rates 3.5/5 (13th percentile of 16 Home Backup-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.
Both Are Fixtures — the AC500 Is the Heavier One
Be honest about this: the AC500 stack is the heavier unit, around 196 lb to the EP500Pro's 182. Neither moves without wheels and a second person, and the 9-lb difference between them is noise at this scale. If you're picturing either of these as something you relocate, recalibrate — they go where you install them and they stay there.
Sealed at 5,120Wh — When That's Fine, and When It Isn't
The EP500Pro's fixed capacity is a genuine simplicity win: no expansion port means one fewer connector to fail, and 5,120Wh is plenty for everyday backup. The problem is direction. The AC500 starts higher at 5,530Wh and can add batteries, so the sealed unit is also the smaller one, and its ceiling is exactly what loses it a full off-grid day. A fixed capacity is a fair trade only when the fixed number is the bigger number — here it's the smaller one.
Full record above — the Test Desk pick is the AC500 + 2×B300K.
Check AC500 + 2×B300K price →or check the EP500Pro 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
Reaching the cycle rating means ~80% capacity remains — degraded, not dead.
Analyst note
Both units cost the same to own over their rated lives — $0.2/kWh each. Lifetime cost can't separate them, so decide on the sticker price and everything else. One thing to know reading the table: both carry the same 3,500-cycle rating, so the lifetime rows are sticker price and capacity in disguise — the wear horizon is identical and decides nothing here.
Growth path
AC500 + 2×B300K
EXPANDABLESupports BLUETTI expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 5,530Wh.
Accepts up to 3,000W of solar. Enough for a serious multi-panel array.
Limited ports. You'll likely need a power strip or splitter.
Expansion batteries are BLUETTI-specific. You're investing in the BLUETTI ecosystem.
EP500Pro
FIXED CAPACITYFixed at 5,120Wh — a sealed, complete system rather than a starting point. There's no expansion port, so that figure is the ceiling: check it against your longest unplugged stretch before you buy.
Accepts up to 2,400W of solar. Enough for a serious multi-panel array.
Adequate ports for most setups, but heavy users may want a power strip.
Realistic full solar rechargeat 70% of rated panel output — see methodology
Analyst note
The EP500Pro is sealed at 5,120Wh, which is fine if that covers you. The AC500 + 2×B300K starts at 5,530Wh and can grow beyond it with BLUETTI expansion batteries — real headroom the EP500Pro doesn't have if your needs climb toward partial-home backup.
What Owners Report
Patterns from published owner reports and long-term reviews — every claim cited to its source below.
BLUETTI AC500 + 2×B300K
Wired in as standby power, the AC500 does the core job well, with a couple of quirks worth knowing before you commit. A named owner running it as a UPS measured about 31W of idle draw and figured that buys 8-plus hours of hold time on the packA5. The same install log flags two oddities: on grid pass-through it pulled roughly 35W more than the actual loadA3, and it won't fully shut down without physically disconnecting the battery, because the BMS stays awakeA4. Neither is a dealbreaker; both are the kind of thing you'd rather learn here than in your utility room.
Livability is a mixed bag. The fan is intermittent rather than constant but audible when it spins upA10, and the indicator lights stay bright enough that one reviewer warned against keeping the unit where you sleepA11 — fine for a garage or a closet, less so for a bedroom. The evidence carries one honest caveat: no long-term review of the exact two-battery stack exists, so these notes come from the AC500 paired with a single B300K — the same base platform, just wired one-to-two.
“So far pretty darn happy, and it's much quieter than the small Pecron E1500LFP I have.”
Sources
firewoodhoardersclub.com · thesolarlab.com · freshlycharged.com · diysolarforum.com
BLUETTI EP500Pro
The EP500Pro is the rare unit with a genuine long-term record, and it's a good one. A year-and-a-half-later test found it still working superbly, holding about 49% charge after roughly a year in storage, and recharging from half to full in about an hour and a halfB1B2B3. Its fan is quietB6 and its output stays rock-solid even at high loadB9. For a sealed box meant to wait years for an outage, that track record is the whole point.
The knocks are the ones you'd expect from a first-generation design. The display shows no estimated runtime and washes out in direct sunB5, and the app can't schedule outputs or tell you when charging will finishB8. Support is hard to reachB4, and one secondhand buyer got stonewalled entirely — BLUETTI declined to help on a used unit throwing an error codeB10. And it's heavy in a way that pins it in place: around 182 lb, too much for two people to wrestle upstairsB7B11.
“After 1.5 years, the system still works superbly — there's still plenty of battery capacity, and it all seems to be operating how it did from the beginning.”
Sources
cleantechnica.com · freshlycharged.com · trustedreviews.com · diysolarforum.com · technicaltrendy.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
- Multiple sources report AC500 units arriving with hardware faults — a dead inverter or a missing battery-link cable — that required contacting Bluetti support. [AC500 + 2×B300K · 2 entries]
- Fan noise is intermittent but noticeable during charging/heavy load across sources, though one owner found it quieter than a competing unit. [AC500 + 2×B300K · 2 entries]
- The app covers the basics but owners want more detail (time-remaining, battery voltage), and the unit lacks a hard-reset option to recover from glitches. [AC500 + 2×B300K · 2 entries]
- Reviewers repeatedly flag the EP500 Pro's 180+ lb weight as making it essentially immovable without its wheels, needing two people to shift it upstairs. [EP500Pro · 2 entries]
- Long-term owners report the EP500 Pro holds its charge and function well after a year-plus in storage, with minimal capacity loss. [EP500Pro · 2 entries]
- The app and display are called out as limited on real-time detail (no runtime estimate, no output scheduling) despite solid core power performance. [EP500Pro · 2 entries]
- A3
“Only thing I see so far... when it switched to grid power it was drawing approximately 35 watts more than the actual usage.”
firewoodhoardersclub.com — jtakeman, AC500 w/B300K install and review thread · 2025-02 · [negative]
- A4
“Only drawback is it needs to be disconnected to shut the Bluetti unit down, as it keeps the BMS active and won't let it shut down.”
firewoodhoardersclub.com — jtakeman, AC500 w/B300K install and review thread · 2025-03 · [negative]
- A5
“Using about 31 watts an hour as a UPS — at 85% that should last about 8+ hours. Priceless!!”
firewoodhoardersclub.com — jtakeman, AC500 w/B300K install and review thread · 2025-03 · [positive]
- A10
“The fan can get loud, though it's only intermittent and doesn't run constantly.”
freshlycharged.com — Powering A Room with Solar: Bluetti AC500 & B300K Review · unknown · [mixed]
- A11
“The indicator lights are quite bright and remain on all the time, so it's best not to keep the AC500 in a room where you'll be sleeping.”
freshlycharged.com — Powering A Room with Solar: Bluetti AC500 & B300K Review · unknown · [negative]
- B1
“After 1.5 years, the system still works superbly — there's still plenty of battery capacity, and it all seems to be operating how it did from the beginning.”
cleantechnica.com — BLUETTI EP500 Pro — 1½ Years Later · 2025-03 · [positive]
- B2
“Pulled from storage after about a year, the unit still retained roughly 49% charge — self-discharge over that time was minimal.”
cleantechnica.com — BLUETTI EP500 Pro — 1½ Years Later · 2025-03 · [positive]
- B3
“After a long storage period, it charged from 50% to 100% in about 1 hour 35 minutes on a standard 120V outlet.”
cleantechnica.com — BLUETTI EP500 Pro — 1½ Years Later · 2025-03 · [positive]
- B4
“Customer service is difficult to get in contact with.”
freshlycharged.com — Bluetti EP500Pro Review: This Thing is Big and Smart! · unknown · [negative]
- B5
“The display does not show the estimated run time, and it gets washed out in direct sunlight.”
freshlycharged.com — Bluetti EP500Pro Review: This Thing is Big and Smart! · unknown · [negative]
- B6
“The fan on the EP500 Pro is very quiet.”
freshlycharged.com — Bluetti EP500Pro Review: This Thing is Big and Smart! · unknown · [positive]
- B7
“At 83kg it's far too heavy for a single user to lift — even two fit people would struggle to move it upstairs.”
trustedreviews.com — Bluetti EP500Pro Review: A staggering amount of power · unknown · [negative]
- B8
“The app doesn't do the sums to let you know when you can expect it to stop charging, and you can't schedule the AC or DC outputs.”
trustedreviews.com — Bluetti EP500Pro Review: A staggering amount of power · unknown · [negative]
- B9
“Power output is rock-solid and very stable, even at high load.”
trustedreviews.com — Bluetti EP500Pro Review: A staggering amount of power · unknown · [positive]
- B10
“A used EP500 Pro threw error code 006 (SPS voltage low) and wouldn't charge or power any ports; Bluetti refused support since the owner wasn't the original buyer.”
diysolarforum.com — "help with my bluetti ep500pro" thread · unknown · [negative]
- B11
“It weighs 182 pounds, which makes it less portable than some other power stations on the market.”
technicaltrendy.com — BLUETTI EP500Pro Solar Power Station Review · unknown · [negative]
Research compiled July 18, 2026.
Who Should Buy Which
Buy the AC500 + 2×B300K if you…
- →You want the most capability for the money — 5,530Wh, 5,000W continuous, and a 10,000W surge for $200 less.
- →Your needs might grow — the AC500 expands past 5,530Wh; the EP500Pro never will.
- →You run a full off-grid day — the AC500 clears about 4,685Wh on one charge where the sealed EP500Pro comes up short.
Buy the EP500Pro if you…
- →You value a proven track record over specs — a documented 1.5-year field record the new stack can't match yetB1.
- →You want one sealed, integrated box with a quiet fan and no cables to addB6 — simplicity over expandability.
- →Your loads are modest and fixed — 3,000W and 5,120Wh comfortably cover a fridge, lights, and electronics with no plans to scale up.
If neither fits
If you need to move it, walk away from both: these are 182-to-196-lb fixtures that need wheels and two people, not power stations you carry. And if your real target is whole-home 240V coverage or more than a single off-grid day of storage, both are a size short — start with a DELTA Pro Ultra-class system or a bigger stack instead of maxing out either of these.
The Bottom Line
The AC500 + 2×B300K is more unit for less money. For $200 under the EP500Pro it gives you 410Wh more capacity, 2,000W more output, room to expand, and the only full-off-grid-day coverage of the two — a lead our composite books at 1,236 points. On the spec sheet, the EP500Pro doesn't win a single line.
What the EP500Pro wins is time. It's the sealed, first-generation box with a year-and-a-half of documented service behind itB1, and for a buyer who prizes a proven, plug-and-forget unit over watts and headroom, that's a fair reason to pay more for less. Everyone else should take the newer stack: it does more today, grows tomorrow, and costs less to do both.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
BLUETTI AC500 + 2×B300K or EP500Pro — which should I buy?
The AC500 + 2×B300K for most people. It costs $200 less, holds 410Wh more, runs 2,000W more continuous output, and can expand where the EP500Pro is sealed for life. Choose the EP500Pro only if a proven, integrated design with a documented long-term record matters more to you than capability or price.
Is the EP500Pro's fixed capacity actually a problem?
It can be. At 5,120Wh sealed, it covers everyday backup fine, but it can't be expanded and it comes up short on a full off-grid day of about 4,685Wh. The AC500 starts higher at 5,530Wh and adds batteries, so its ceiling moves with your needs while the EP500Pro's stays put.
Why is the older EP500Pro still worth considering?
Its track record. Long-term testing shows it working like new after a year and a half and holding charge well through long storage, with a quiet fan and stable output. The two-battery AC500 stack has no comparable field history yet, so if proven reliability outranks specs for you, the EP500Pro earns the look.
How much more powerful is the AC500 in practice?
Meaningfully. It runs 5,000W continuous to the EP500Pro's 3,000 and surges to 10,000W against 6,000 — roughly two-thirds more running power and nearly double the surge. That headroom lets it start large motor loads, like a central AC compressor, that the EP500Pro's smaller inverter would struggle to bring online.
Are these portable at all?
No. The EP500Pro is around 182 lb and the AC500 stack about 196; reviewers say even two people struggle to move the EP500Pro upstairs. Both roll on wheels and both are meant to live in one spot. If portability is on your list, neither belongs on it.
Where to buy
BLUETTI AC500 + 2×B300KPick
$3,948.00
$3,948.00 · direct from BLUETTI
Last checked 22 days ago. Prices move — check before you buy.
BLUETTI EP500Pro
$3,499.00
$3,499.00 · direct from BLUETTI
Last checked 6 days ago. Prices move — check before you buy.
Prices may vary by retailer and are subject to change.