Head-to-head test
BLUETTI AC500 + 2×B300K vs BLUETTI Apex 300 + B500K
Same brand, same 3,500-cycle cells — but the Apex 300 + B500K holds about 2,355Wh more, costs $100 less, weighs 13 lb less, and carries a 5-year warranty the AC500 stack doesn't. The only reason to pay up for the AC500 is its bigger inverter: 5,000W continuous and a 10,000W surge against 3,840 and 7,680.
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
Apex 300 + B500K
7,232Power Score · The AC & Fridge Zone
$3,499.00 · direct from BLUETTI
Last checked 6 days ago. Prices move — check before you buy.
Spec deltas
The Apex 300 + B500K holds more energy, costs less, and comes with a warranty the AC500 + 2×B300K doesn't — from the same company, on the same cells. About 7,885Wh against 5,530, $3,199 against $3,299, five years of coverage against none. This isn't a battery fight so much as a generational one, and the newer unit is winning it.
The two share the parts that usually matter most in a stack this size: 3,500-cycle LFP chemistry, a 100W USB-C port, and an expansion path that keeps either from being a dead end. Where they split is everything downstream of the cells. The Apex is 13 lb lighter at 183 to 196, settles onto grid power as a line-interactive UPS under 10ms rather than the AC500's standby-class 20, and discloses a 45dB load rating where the AC500 publishes no noise figure at all. It also costs less to own over its life: $0.12 per lifetime kWh to $0.17.
The AC500 holds one card, and it's worth naming before you write it off. Its inverter runs 5,000W continuous with a 10,000W surge; the Apex does 3,840W and 7,680W. Central air conditioners and well pumps draw two to three times their rated wattage the instant they start, and that surge headroom is where a 10,000W inverter starts a motor a 7,680W one refuses to. If your backup list includes a compressor that big, the AC500 earns its premium. If it doesn't, you're paying more for less battery and watts you'll never call on.
What the Numbers Reveal
Each conclusion stated first — the numbers behind it on one line, the full analysis below.
More capacity is supposed to cost more money; the Apex undercuts the AC500 stack by $100 and still hands you about 2,355Wh more on identical 3,500-cycle chemistry, which is exactly how it reaches $0.12 per lifetime kWh against $0.17. The 5-year warranty is stacked on top of the lower price, not traded for it.
Apex 300 + B500K is $3,199 to the AC500 stack's $3,299Apex holds about 7,885Wh to 5,530 — roughly 2,355Wh more, on the same 3,500-cycle cellsApex costs $0.12 per lifetime kWh to the AC500's $0.17
Why it mattersAnyone choosing on value has no reason to reach for the AC500 — the Apex is cheaper twice and larger once.
continuous output
Set capacity, cycles, and expandability aside — where the Apex leads or matches — and the AC500's whole case collapses to 1,160W more continuous output and a 2,320W bigger surge. That headroom starts a 3-ton compressor or a deep well pump the Apex's 7,680W might trip on, and it does nothing whatsoever for a fridge and a router.
AC500 runs 5,000W continuous with a 10,000W surge; Apex does 3,840W and 7,680WComposite scores the Apex 7,794 to the AC500's 6,612 — a 1,182-point leadBoth hold LFP cells rated 3,500 cycles, and both expand
Why it mattersTie the AC500's premium to a real motor load. Big compressor, pay it; electronics and lights, the Apex is the same brand's battery for less.
The Apex switches a hair faster, tells you how loud it gets — 45dB, roughly a running refrigerator — and is 13 lb easier to slide across a garage. No single one of these decides the pair, but they all lean the same way, and a unit that won't disclose its own noise number is usually the louder one.
Apex catches an outage as a line-interactive UPS under 10ms; the AC500 does it standby-class under 20Apex publishes a 45dB load rating; the AC500 publishes no noise figureApex is 13 lb lighter at 183 to 196
Why it mattersFor a UPS living in or near a room you actually use, the Apex is the easier unit to have around.
The specific dimensions that decide these two units — everything else is a tie.
Lifetime Value
Selected because: Apex is cheaper to buy, cheaper to own, and bigger — the spine of the verdict.
cost / lifetime kWh
The Apex is the rare unit that's cheaper to buy and cheaper to keep. Its $3,199 sticker undercuts the AC500 stack by $100, and because it carries about 2,355Wh more on the same 3,500-cycle cells, it delivers more lifetime energy per dollar — $0.12 per lifetime kWh against the AC500's $0.17. The bigger battery is also the thriftier one, which is not how this usually goes.
The warranty widens the gap instead of closing it. The Apex carries five years of coverage; the AC500 stack lists none, which on a $3,299 purchase is a real blank to sign. You'd be paying more money for less battery and taking on more risk at the same time. Unless the AC500's inverter is doing something specific for you, the value case is one-directional.
PowerScore Breakdown
Selected because: Composite favors the Apex by 1,182; the AC500's only lead is inverter output, framed here.
overall power score
Our composite scores the Apex 7,794 to the AC500's 6,612, and the 1,182-point margin is mostly capacity doing the work — more energy on cells just as durable. On the battery itself, the newer unit is simply the bigger, better-value one.
The inverter is the AC500's one clean win, and it's a genuine one. It pushes 5,000W continuous to the Apex's 3,840 and surges to 10,000W against 7,680 — a 2,320W bigger cushion for the instant a motor spins up. Central-AC compressors and well pumps spike well past their running draw at startup, and the larger inverter is the one that starts them without tripping. That is the entire reason to buy the AC500 over its newer sibling. If your loads don't include a motor that big, you're paying for surge you'll never see.
Portability & Form Factor
Selected because: 13 lb lighter Apex, but both are two-person fixtures — 'lighter, not light.'
weight
At 183 lb the Apex is 13 lighter than the 196-lb AC500 stack, and if this thing ever moves, that's the number you feel first. It's the difference between two people straining and two people managing — still not a unit you carry to a tailgate, but a bit less punishing to reposition in a basement or an RV bay.
Keep the expectation honest, though: 13 lb off a 196-lb starting point is lighter, not light. Both are two-person, wheel-it-if-you-can fixtures that live where you first set them down. If the unit never moves, this row is a wash and the decision goes back to capacity and price; if it moves even occasionally, the Apex's 13 lb is a small mercy worth having.
Your Life, Your Pick
Selected because: Apex wins the three big-draw scenarios on capacity; van-life margin is the clearest.
The bigger battery quietly wins the scenarios that stress capacity. An eight-hour blackout leaves the Apex at 25% used against the AC500's 35%, and a full off-grid day is the sharpest split of all: the Apex covers it on about 70% of usable capacity while the AC500 stack finishes the same day at 100% — coasting in on empty.
The smaller draws — a CPAP night, a workday, a tailgate — are ties, because both packs are large enough to shrug them off. So the scenario table doesn't hand the AC500 a single outright win; the closest it comes is the surge headroom for something large kicking on mid-outage, which is the inverter argument again, not a capacity one.
What the Specs Don't Tell You
Selected because: UPS class, Apex's disclosed 45dB vs the AC500's blank, and the Apex's firmware/port caveat live here.
The livability details all tilt to the Apex. It catches an outage as a true line-interactive UPS under 10ms to the AC500's standby-class 20 — a narrow edge that only matters for genuinely switchover-sensitive gear — and it owns a 45dB load rating where the AC500 publishes nothing. Neither is silent; only one tells you the number going in.
The honest catch cuts the Apex's way, and it's worth pricing in. Reviewers report firmware and app updates that have locked units into the wrong mode or thrown inverter errors before a later update sorted themB7B9, and the base unit's native-port layout is thin enough that a full DC and USB array leans on a paid hub accessoryB12. The configured stack does list a 100W USB-C port, but confirm your exact port needs before ordering rather than after.
Strengths & trade-offs
BLUETTI AC500 + 2×B300K
Strengths
- +Higher AC output
- +Faster solar charging
Trade-offs
- –Significantly heavier (+13.1 lbs), making it harder to move.
- –Very heavy unit that may be difficult for one person to lift.
BLUETTI Apex 300 + B500K
Strengths
- +Costs $449 less
- +Lighter by 13.1 lb
- +Larger battery capacity
- +Longer warranty
Trade-offs
- –Weaker inverter (-1,160W) limits appliance compatibility.
- –Very heavy unit that may be difficult for one person to lift.
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 Apex 300 + B500K at 183 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
Apex 300 + B500K
An eight-hour outage draws about 1,645Wh, and both stacks ride it out with most of the pack intact — the Apex at about 25% used, the AC500 at 35%. Capacity isn't the deciding factor at this load, so the tiebreak is the Apex's faster line-interactive switchover and its warranty against the AC500's surge headroom for anything large that kicks on mid-outage.
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 Apex 300 + B500K at 183 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
Apex 300 + B500K
A full off-grid day pulls about 4,685Wh, and the capacity gap finally bites here. The Apex covers the day on roughly 70% of its usable pack; the AC500 stack covers the same day at 100% — finishing on empty, with nothing held back for a slow solar morning. Both technically make it, but only the newer, cheaper unit walks away with a cushion.
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: Apex 300 + B500K runs 32.7h vs 22.9h.
$3,499 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 0–446.8hComfort & Convenience
Makes off-grid life actually enjoyablescale 0–89.4hHigh-Draw Appliances
These reveal the real limitsscale 0–6.7h¹ 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 Apex 300 + B500K
The Apex 300 + B500K is BLUETTI's newer architecture, and against its own older sibling it wins nearly everywhere the money lives. It holds about 7,885Wh to the AC500 stack's 5,530 — roughly 2,355Wh more — on the same 3,500-cycle LFP cells, costs $100 less ($3,199 vs $3,299), weighs 13 lb less, catches an outage faster as a line-interactive UPS under 10ms against the AC500's standby-class 20, and adds a 5-year warranty where the stack lists none. Its cost to own lands at $0.12 per lifetime kWh to the AC500's $0.17, and it leads our composite 7,794 to 6,612. The AC500 keeps exactly one advantage: inverter muscle. Its 5,000W continuous and 10,000W surge clear what the Apex's 3,840W and 7,680W might stall on — a central AC compressor, a deep well pump. Buy the AC500 for that and nothing else. One honest catch on the Apex: reviewers flag firmware-update wobbles and a sparse native-port layout on the base unitB7B12, so confirm your port needs before ordering.
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.
$3,499.00 · direct from BLUETTI
Last checked 6 days ago. Prices move — check before you buy.
or check the AC500 + 2×B300K price$3,948.00 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 Apex 300 + B500K rates 3.5/5 (11th percentile of 29 Whole-Home / Off-Grid-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.
Weight Reality Check
Neither unit is grab-and-go. The Apex 300 + B500K (183 lbs) is a two-person lift. The AC500 + 2×B300K (196.1 lbs) is firmly a two-person lift. It goes where you put it and stays there. That's a 13 lb difference.
Apex 300 + B500K: 45dB Under Load
45dB is about as loud as a running refrigerator. The AC500 + 2×B300K publishes no figure to compare it against, which cuts both ways. For most people, fan noise around 45dB and up is where sleep starts to suffer.
Line-Interactive vs Standby: A Few Milliseconds
The Apex catches an outage as a line-interactive UPS under 10ms; the AC500 does it standby-class under 20. For a desktop, a router, or most home electronics, both are quick enough that nothing blinks. The gap only shows up on genuinely switchover-sensitive gear, and even there it's a narrow edge to the Apex — worth noting, not worth deciding the purchase on by itself.
One Unit Publishes Its Noise Number
The Apex owns a 45dB load rating — roughly a running refrigerator, the kind of figure you can plan a bedroom or a home office around. The AC500 stack publishes nothing. Neither is silent under load, but with the Apex you know what you're signing up for going in, and with the AC500 you find out after it's on your shelf. A blank noise spec usually isn't hiding good news.
Full record above — the Test Desk pick is the Apex 300 + B500K.
Check Apex 300 + B500K price →or check the AC500 + 2×B300K 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 Apex 300 + B500K wins on both sticker price and long-term value. At $0.13/kWh over its lifetime, it's meaningfully cheaper to own. Clear value winner. 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.
Apex 300 + B500K
EXPANDABLESupports BLUETTI expansion batteries, so you can add capacity later without replacing the base unit — useful if your needs may climb past 7,885Wh.
Accepts up to 2,400W of solar. Enough for a serious multi-panel array.
Generous port selection supports complex multi-device setups.
Expansion batteries are BLUETTI-specific. You're investing in the BLUETTI ecosystem.
Realistic full solar rechargeat 70% of rated panel output — see methodology
Analyst note
Both expand, so neither locks you out of growth — decide on capacity, price, and the rest, not the expansion checkbox.
What Owners Report
Patterns from published owner reports and long-term reviews — every claim cited to its source below.
BLUETTI AC500 + 2×B300K
The AC500's field record is mostly about small daily friction once the unit is running. The display shows battery percentage but no time-to-empty and no voltage, which owners moving up from EcoFlow or Pecron notice immediatelyA2; the unit won't fully power down without disconnecting the battery, because the BMS stays activeA4; and there's no hard-reset button to recover from a glitch, which more than one reviewer found genuinely frustratingA8. None of it is a dealbreaker, but it's the texture of living with the thing.
Underneath the nitpicks, owners are largely content. One called it near-flawless from day one with an easy setup and a nice monitoring appA12, and another was simply happy, noting it ran quieter than his previous Pecron unitA1. There's a quality-control asterisk worth respecting — a test outfit had an AC500 arrive with the battery on but the inverter deadA7 — so buy from a seller with a clean return path. One limit on the evidence itself: no long-term review of the exact two-battery stack exists yet, so these notes describe the AC500 wired to a single B300K, the same base platform one-to-one instead of 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 Apex 300 + B500K
The Apex 300's standout in the field is how quiet it is for its output class. Independent reviewers describe the dual-fan cooling as tame and even under load — one put its noise control on par with the quietest units from EcoFlow and DJIB1, another said it stays usable near a sleeping area without a distracting pitch or rattleB13. For a stack this size, that restraint is unusual and genuinely praised.
The rough edges are software and handling. Firmware and app updates have repeatedly caused trouble — a unit stuck in the wrong mode after an update, an inverter error code, a download that failed until the next patch — though the threads generally show the issue resolving eventuallyB7B8B9. Owners running units in parallel also report uneven charge rates that need a community-devised workaround to keep in syncB3B4, and the base unit's sparse native ports draw steady criticismB12. Read all of this as early days, and read it with one caveat: none of the located reports confirm the exact Apex 300 + B500K pairing, so treat this as the platform's record, not this precise configuration's.
“Turns out the Apex 300's noise control is on par with the quietest power stations on the market, like those on offer from EcoFlow and DJI.”
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]
- Multiple independent reviewers describe the dual-fan cooling as noticeably quiet/even for a unit of this output class, even under load. [Apex 300 + B500K · 3 entries]
- Firmware and app updates have repeatedly caused mode-lock, download failures, or inverter error codes; several threads show the issue eventually resolved after further updates or support contact. [Apex 300 + B500K · 4 entries]
- When running multiple Apex 300 units or expansion batteries in parallel, owners report uneven charge rates between units, with community-devised (unofficial) workarounds needed to keep them in sync. [Apex 300 + B500K · 2 entries]
- The stripped-down, modular design draws criticism for real-world handling: extreme weight makes it hard to move, and lack of native USB/DC ports forces reliance on a separate paid hub accessory. [Apex 300 + B500K · 2 entries]
- A1
“So far pretty darn happy, and it's much quieter than the small Pecron E1500LFP I have.”
firewoodhoardersclub.com — jtakeman, "Bluetti AC500 w/B300K battery for our home backup/supplement system install and review" · 2025-02 · [positive]
- A2
“One other odd thing — it doesn't have a time-of-charge-remaining readout like my EF or Pecron units, just battery percentage. They don't even display battery voltage.”
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]
- A7
“Both the AC300 and AC500 we tested had issues where the battery would turn on but not the inverter itself — dead on arrival, essentially.”
thesolarlab.com — Bluetti AC500 Review: Pros, Cons & the Ugly Truth · unknown · [negative]
- A8
“The lack of a hard reset button on these units is also really frustrating.”
thesolarlab.com — Bluetti AC500 Review: Pros, Cons & the Ugly Truth · unknown · [negative]
- A12
“Performed near flawlessly from day one, with easy-to-understand setup and a nice app for monitoring.”
diysolarforum.com — "Bluetti ac 500" owner thread · unknown · [positive]
- B1
“Turns out the Apex 300's noise control is on par with the quietest power stations on the market, like those on offer from EcoFlow and DJI.”
The Solar Lab — "Bluetti Apex 300 Review: Cheap, Practical Home Backup?" · unknown · [positive]
- B3
“The Apex 300 have some major charging problems... When the units are charging from the grid they charge at different rates and not together.”
DIY Solar Power Forum — "Bluetti Apex 300 problems" · 2025-09 · [negative]
- B4
“I have found a simple way to get around some of the solar charging limitations with multiple APEX 300s hooked up in parallel... So far, I have not had any problems with my setup.”
DIY Solar Power Forum — "Bluetti Apex 300 problems" · 2025-09 · [mixed]
- B7
“I updated my Apex 300 to the latest firmware yesterday. Now it's stuck in 'Backup' mode... when I go into the app to try to change it back, it flashes to...”
BLUETTI Community — "Apex 300 stuck in Backup mode after last firmware update" · 2025-11 · [negative]
- B8
“There was an update on my Apex 300 a few days ago IOT v8026.12... Problem is every time I connect to the power st[ation]... Edit - This seems fixed now hooray!”
BLUETTI Community — "Check For Update App issue" · 2025-09 · [mixed]
- B9
“After the update completed, the charging stopped and I received Error 004... I have error E004 Inverter Output Failure.”
BLUETTI Community — "Error E004 Apex 300" · 2025-11 · [negative]
- B12
“The Apex 300 doesn't have USB ports, DC ports, or much of anything beyond its six AC plugs and high-voltage connectors.”
The Solar Lab — "Bluetti Apex 300 Review: Cheap, Practical Home Backup?" · unknown · [negative]
- B13
“Fan noise remains even, with no distracting pitch or rattle. This makes the Apex 300 usable near sleeping areas or indoor workspaces without disturbance.”
Yanko Design — "BLUETTI Apex 300 Review" · 2025-05 · [positive]
Research compiled July 18, 2026.
Who Should Buy Which
Buy the AC500 + 2×B300K if you…
- →You're starting a central AC, a deep well pump, or another big motor — the 5,000W continuous and 10,000W surge clear what the Apex's 7,680W might stall on.
- →You want the built-in port array without shopping for an add-on hub to fill it out.
- →You're extending an existing AC500-family system and want the higher-output inverter as the hub.
Buy the Apex 300 + B500K if you…
- →You're choosing on value — $100 less, about 2,355Wh more, and a lower $0.12 per lifetime kWh.
- →You want the safety net — five years of warranty against the AC500 stack's none.
- →You want the more livable unit — 13 lb lighter, a faster line-interactive UPS, and a disclosed 45dB where the AC500 says nothing.
If neither fits
If you need true whole-home coverage — 240V split-phase, a daily budget past about 7,885Wh, or a decade-long warranty — both of these are a size too small, and a DELTA Pro Ultra-class system is the honest starting point. And if you wanted something you actually carry, stop here: at 183 to 196 lb these are fixtures that live where you set them, not power stations you sling into a trunk.
The Bottom Line
Same brand, newer battery, more of it, for less money. The Apex 300 + B500K beats the AC500 + 2×B300K on capacity, price, weight, warranty, UPS speed, and cost to own — $0.12 per lifetime kWh against $0.17 — and our composite confirms it 7,794 to 6,612. On the battery itself, there's no argument to make for the older unit.
The AC500 keeps one reason to exist beside it: a 5,000W inverter with a 10,000W surge, the headroom to start a central AC or well pump the Apex might stall on. Buy it for that and nothing else. If your backup list is fridges and routers rather than compressors, take the Apex, keep the $100, pocket the extra 2,355Wh, and enjoy a warranty the AC500 doesn't come with.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
BLUETTI AC500 + 2×B300K or Apex 300 + B500K — which is the better buy?
For most people, the Apex 300 + B500K. It holds about 2,355Wh more than the AC500 stack on the same 3,500-cycle cells, costs $100 less, weighs 13 lb less, and adds a 5-year warranty the AC500 doesn't list. Choose the AC500 only if you need its higher output — 5,000W continuous and a 10,000W surge — to start a large motor like central air or a well pump.
Why does the pricier AC500 also cost more per lifetime kWh?
Because the Apex holds more energy on the same durable cells. Both use 3,500-cycle LFP chemistry, but the Apex packs about 2,355Wh more, so it spreads its slightly lower price over more lifetime energy — $0.12 per lifetime kWh to the AC500's $0.17. The bigger battery is the cheaper one to own here.
What do I give up by choosing the Apex 300?
Inverter headroom, and possibly some ports. The Apex runs 3,840W continuous and surges to 7,680W, below the AC500's 5,000W and 10,000W, so a very large motor startup is the one thing it might not handle. Reviewers also flag the base unit's thin native-port layout, so confirm the Apex config covers your DC and USB needs before ordering.
Are these actually portable?
Not in any real sense. The Apex stack is about 183 lb and the AC500 stack about 196; both are two-person or wheeled lifts that stay where you place them. The Apex's 13-lb advantage helps when you reposition either around a home or RV, but treat both as fixtures rather than anything you carry.
Does the AC500's higher wattage matter for normal home backup?
Only if your loads are big. For a fridge, a router, lights, and laptops, the Apex's 3,840W is ample. The AC500's 5,000W continuous and 10,000W surge earn their keep on hard-starting motors — a 3-ton central AC or a deep well pump — where the extra surge is the difference between the compressor starting and the inverter tripping.
Where to buy
BLUETTI AC500 + 2×B300K
$3,948.00
$3,948.00 · direct from BLUETTI
Last checked 22 days ago. Prices move — check before you buy.
BLUETTI Apex 300 + B500KPick
$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.