Head-to-head test
BLUETTI Apex 300 + B300K vs BLUETTI Apex 300 + B500K
BLUETTI Apex 300 + B300K vs BLUETTI Apex 300 + B500K: buy the B500K build if it will run every day or through outages that reach a third night, since its extra battery costs less per watt-hour; buy the B300K only if your loads stay well inside its smaller pack.
Full profiles: BLUETTI Apex 300 + B300K β Β· BLUETTI Apex 300 + B500K β
Written by Gunner GustafsonUpdated
Whole-Home Backup Tester, Station Arena Test Desk
Spec deltas
Storms in my canyon don't keep office hours, and they routinely take out the grid. So the first thing I ask of a home battery is how many nights it buys me.
The top half is the same Apex 300 in both, with the same 3,840W inverter, solar input and UPS mode, which is the battery taking over when the wall power stops. The bottom half is the battery pack. The B300K build holds 5,529.6Wh and the B500K holds 7,884.8Wh.
The bigger pack costs $700 more. After a modeled 8-hour blackout night, the B300K has nearly two more like it left and the B500K about three.
What the Numbers Reveal
Each conclusion stated first β the numbers behind it on one line, the full analysis below.
cost / lifetime kWh
The blended price per watt-hour falls as the battery grows, and the lifetime cost per kWh falls with it.
B300K build is $2,599 for 5,529.6Wh; B500K build is $3,299 for 7,884.8Whthe price gap is $700 for 2,355.2Wh more capacitycost per lifetime kWh: $0.08 (B300K) vs $0.07 (B500K)
Why it mattersIf the $700 is in the budget, that extra capacity is the cheapest battery on this page.
Fifteen watt-hours is about one phone charge. A longer night, a cold morning or a cloudy recharge day uses that up and then some. The B500K's leftover is a real cushion, though not a second day.
a modeled 24-hour van-life load needs 4,685Whthe B300K build uses nearly all of its usable capacity and keeps 15Whthe B500K build uses 70% and keeps 2,017Wh
Why it mattersIf this runs every day, pay for the cushion.
The specific dimensions that decide these two units β everything else is a tie.
Lifetime Value
Selected because: The core argument: the B500K's extra capacity costs less per watt-hour than the base build.
cost / lifetime kWh
The two builds share every part except the battery, so this comes down to price per watt-hour, and the bigger build wins it. Ownership cost points the same way, at $0.07 per lifetime kWh for the B500K and $0.08 for the B300K.
Your Life, Your Pick
Selected because: Repeat days, a long outage or van life, are the only loads that separate these two builds.
At ordinary loads the extra battery is spare room you won't touch. A CPAP night or a remote workday uses a small slice of either build. An 8-hour blackout uses about a third of the B300K and a quarter of the B500K.
The gap opens on repeat days. If a storm kept the line crews off my road for three nights, the B300K would run out during the third and the B500K wouldn't. For that week I'd wire the B500K into my transfer switch.
What the Specs Don't Tell You
Selected because: Beyond capacity, weight is the only spec that moves, and both are installs rather than carry-alongs.
Weight was settled before the extra battery arrived. One reviewer says the bare Apex 300 alone is too much for most people to carryA14. Both builds arrive as stacks of separate boxes, 148.8 pounds against 183, so nobody lifts either one in a single piece. The extra 34 pounds all sits in the battery box, which makes that box the harder lift.
Noise doesn't separate them. Both list the same 45dB, a best-case figure for the same base with the same fans.
BLUETTI's 7,680W Power Lifting figure only applies to resistive loads, the kind that turn electricity straight into heat, and it works by feeding them less power. Neither record publishes a surge figure for starting a motor, so plan a well pump or a compressor around the 3,840W continuous rating.
Growth Path
Selected because: Both expand the same way, so growth is a matter of timing.
Both builds sit on the same expandable Apex 300, so either can take more BLUETTI batteries later. You can buy the bigger battery now at the better per-watt-hour price, or start smaller and add a pack later at whatever packs cost then. Since the B500K's extra capacity already comes in under the base rate, waiting only makes sense if the $700 has a better job to do.
Strengths & trade-offs
BLUETTI Apex 300 + B300K
Strengths
- +Costs $700 less
- +Lighter by 34.2 lb
Trade-offs
- βVery heavy unit that may be difficult for one person to lift.
BLUETTI Apex 300 + B500K
Strengths
- +Larger battery capacity
Trade-offs
- βSignificantly heavier (+34.2 lbs), making it harder to move.
- βVery 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 Β· 2 nights Β· needs 2,100Wh
Weekend Camping
Two nights off-grid with essential comfort
Neither unit
Scoring these two at a campsite is a category error: neither travels β the Apex 300 + B300K is 148.8 lbs and the Apex 300 + B500K 183 lbs, and at those weights they roll off a truck bed if they go anywhere at all. The 2,100Wh here is trivial for either β 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
LOADΒ Β Phone Charger 15WΓ6h Β· LED Lights 40WΓ8h Β· Box Fan 75WΓ14h Β· CPAP Machine 40WΓ16h
SCN-02 Β· 8 hours Β· needs 1,645Wh
8-Hour Blackout
Keep the essentials running through a night without power
Apex 300 + B500K
Both survive the night. The Apex 300 + B500K finishes at 25% used with 5,057Wh left β 3.1 more nights like it. The Apex 300 + B300K finishes at 35% with 3,055Wh, 1.9 more nights like it. If your outages tend to run past one evening, that difference is the whole argument between them.
Battery budget usedlower = more headroom
LOADΒ Β Fridge 150WΓ8h Β· Router + Modem 20WΓ8h Β· LED Lights (4 bulbs) 40WΓ6h Β· Phone Charger 15WΓ3h
SCN-03 Β· 8 hours Β· needs 320Wh
CPAP Overnight
Sleep therapy without interruption β the #1 medical use case
Either unit
A CPAP is about 40W for eight hours, so both of these cover the night several times over β capacity isn't the question here. Both happen to list 45dB β the same published figure twice, not a measured tie β so there is nothing in the noise column to separate them either. Buy whichever is cheaper or easier to carry.
Battery budget usedlower = more headroom
LOADΒ Β CPAP Machine 40WΓ8h
SCN-04 Β· 8 hours Β· 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 β pick on weight, ports, or price.
Battery budget usedlower = more headroom
LOADΒ Β Laptop 60WΓ8h Β· External Monitor 30WΓ8h Β· Router + Modem 20WΓ8h Β· Phone Charger 15WΓ2h
SCN-05 Β· 4 hours Β· needs 670Wh
Tailgate Party
Game day power for the crew
Neither unit
Scoring these two at a tailgate is a category error: neither travels β the Apex 300 + B300K is 148.8 lbs and the Apex 300 + B500K 183 lbs, and at those weights they roll off a truck bed if they go anywhere at all. The 670Wh here is trivial for either β 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
LOADΒ Β Blender 400WΓ0.5h Β· LED TV (55") 80WΓ4h Β· Bluetooth Speaker 15WΓ4h Β· Phone Charger (Γ3) 45WΓ2h
SCN-06 Β· 24 hours Β· needs 4,685Wh
Van Life Daily
A full day of mobile living β the ultimate endurance test
Apex 300 + B500K
The Apex 300 + B300K uses 100% of its battery on a full day, leaving 15Wh β miss a solar day and that is the entire cushion. The Apex 300 + B500K at 70% keeps 2,017Wh in hand, a far more forgiving rhythm for full-time living.
Battery budget usedlower = more headroom
LOADΒ Β Mini-Fridge 150WΓ24h Β· Laptop 60WΓ4h Β· Phone Charger 15WΓ3h Β· LED Lights 40WΓ5h Β· Fan 75WΓ8h
The Load Test
RUNTIME = (Wh Γ 0.85) Γ· 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.
$3,299 list Β· direct from BLUETTI
Planning for more than this? Describe your whole setup and get it sizedΒ β
Modeled from the spec record β same math as the tables below. Methodology
Runtime by appliance
Real-world runtime estimates for common appliances, modeled at 85% inverter efficiency.ΒΉ
Essentials
The basics you need runningscale 0β446.8hComfort & Convenience
Makes off-grid life actually enjoyablescale 0β89.4hHigh-Draw Appliances
These reveal the real limitsscale 0β6.7hΒΉ Runtime = (capacity Γ 0.85) Γ· 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 β see methodology.
Conclusion
October 25, 2026
Verdict: the BLUETTI Apex 300 + B500K
Both builds share the same Apex 300 on top, so only the battery changes. The B500K build costs $700 more and holds 2,355.2Wh more, which makes it the cheaper of the two per watt-hour and per lifetime kWh, $0.07 against $0.08. A modeled 24-hour van-life load takes the B300K build down to its last 15Wh, while the B500K finishes with 2,017Wh in hand. The only other cost is 34 more pounds on a unit you install rather than carry. Buy the B300K if your loads stay well inside its pack and you'd rather keep the $700.
Editor-assigned confidence, based on cited owner research and spec analysis.
List prices as of October 25, 2026. The links below open BLUETTI's current price.
$3,299.00 Β· direct from BLUETTI
Last checked 28 days ago. Prices move β check before you buy.
or check the Apex 300 + B300K price$2,599.00 list
Written by Gunner Gustafson, Whole-Home Backup Tester Β· Station Arena Test Desk Β· Updated October 25, 2026
Black Friday Β· 26 days out
Prices to beat:Apex 300 + B300K $2,364Apex 300 + B500K $3,299
The lowest we have recorded for each. We have never seen the Apex 300 + B500K discounted, so any real cut on it would be a first.
Measured Data
Benchmark scores and the full spec record, side by side.
Benchmark scores
Not rated for both units (minimum threshold unmet): Solar Generator.
Full specifications
α΅ Derived: price Γ· rated capacity. See the data behind our comparisons β
Comparison ToolAdd more power stations, side by sideOpen Tool βHow these numbers are produced
Numeric verification
Every figure on this page traces to our spec database or arithmetic on it β no estimated numbers.
Owner claims
Statements about owner experience are cited to published reviews β see Sources & Research Notes below.
Runtime model
Runtime = (rated capacity Γ 0.85 inverter efficiency) Γ· 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 βClass ranking (the star rating)
Each unit's star score is a category ranking, not customer reviews β 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 5β . Here, Apex 300 + B300K rates 4.2/5 (53rd percentile of 20 Home Backup-class units), and Apex 300 + B500K rates 3.5/5 (11th percentile of 37 Whole-Home / Off-Grid-class units).
How the class ranking is computed βTest 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 + B300K (148.8 lbs) is spread across its boxes β no single lift, but nothing you reposition on a whim. The Apex 300 + B500K (183 lbs) is spread across its boxes β no single lift, but nothing you reposition on a whim. That's a 34 lb difference.
Fan Noise: Line Ball
Both units are rated at the same 45dB β like a running refrigerator. One published figure, twice, so noise shouldn't decide this one.
Power Lifting: 7,680W and 7,680W
Both units have BLUETTI's Power Lifting mode: the Apex 300 + B300K to 7,680W on a 3,840W inverter, the Apex 300 + B500K to 7,680W on 3,840W. It works by delivering less power than the appliance asks for rather than more than the inverter has, so the appliance runs slower rather than not at all. BLUETTI scopes the mode to purely resistive loads β a heater, a kettle, an incandescent lamp β so it does nothing for a fridge compressor, a pump or a power tool. Neither record publishes an instantaneous surge figure, so nothing on this card speaks to motor loads. Judge the Lifting figures on which ceiling covers the resistive load you actually own.
Warranty: No Difference
Both units carry the same 5-year warranty, so coverage isn't a tiebreaker here. Both figures are maximums rather than guarantees β they depend on buying direct from BLUETTI or registering the unit, since reseller purchases carry a shorter term. Worth saying because the per-dollar framing can suggest otherwise: the Apex 300 + B300K works out at 1.9 years of cover per $1,000 spent against the Apex 300 + B500K's 1.5, but that spread is the price gap, not the terms.
Full record above β the Test Desk pick is the Apex 300 + B500K.
Check Apex 300 + B500K price βor check the Apex 300 + B300K priceOwnership Analysis
What happens after you buy β 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
β warranty ends Β· Reaching the cycle rating means ~80% capacity remains β degraded, not dead.
Analyst note
The Apex 300 + B300K is cheaper to buy, but the Apex 300 + B500K is cheaper to own. At $0.07/kWh over its lifetime vs $0.08/kWh, the Apex 300 + B500K's higher cycle life and capacity make each dollar go further over the years. One thing to know reading the table: both carry the same 6,000-cycle rating, so the lifetime rows are sticker price and capacity in disguise β the wear horizon is identical and decides nothing here.
Growth path
Apex 300 + B300K
EXPANDABLESupports BLUETTI expansion batteries, so you can add capacity later without replacing the base unit β useful if your needs may climb past 5,530Wh.
Accepts up to 2,400W 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 β useful if your needs may climb past 7,885Wh.
Accepts up to 2,400W 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.
Realistic full solar rechargeat 70% of rated panel output β see methodology
Analyst note
Both expand, so neither locks you out of growth β decide on capacity, price, and the rest, not the expansion checkbox.
What Owners Report
Patterns from published owner reports and long-term reviews β every claim cited to its source below.
BLUETTI Apex 300 + B300K
Most of what's written about the Apex 300 + B300K comes from reviewers with loaner units rather than long-term ownersA0. The common complaint is ports. The base has its AC outlets and high-voltage sockets and little elseA1. USB-C, USB-A and 12V come from the separately sold Hub D1A15, which one reviewer called steep for what it addsA2.
The praise lands on recharge speed and real appliances. One reviewer of the Apex 300 had it ready again in under an hour and called the speed astonishingA12. Another ran a washing machine off the Apex for an hour and watched it take about a third of the chargeA9, then switched on a heat-pump dryer that used most of what was left over an hour and a halfA10. A third said it feels like one of the few systems that could replace a generator, minus the noise and fumesA4.
βThe Apex 300 doesn't have USB ports, DC ports, or much of anything beyond its six AC plugs and high-voltage connectors.β
Sources
thesolarlab.com Β· techspective.net Β· digitalreviews.net Β· thesolarpit.com Β· cleantechnica.com Β· trustedreviews.com Β· bluettipower.com
BLUETTI Apex 300 + B500K
Field reports on this exact build are thin. Our researcher couldn't confirm that any owner post describes the B500K pairing specifically, so read everything here as the Apex 300 platform in generalB0. One reviewer calls the fans relatively tame where some rivals sound like small jet enginesB2. Another says the noise stays even enough for a room near where people sleepB13.
The complaints are mostly firmware. One owner's unit stuck in Backup mode after an updateB7, and another threw an inverter error once an update finishedB9. An owner running several units together reports them charging at different rates from the gridB3. One reviewer could hardly carry the base a few feet and never got it onto a tableB11. We found no report of six months of ownershipB0.
βTurns 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.β
Sources
bluettipower.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
- Reviewers consistently flag that the base Apex 300 has no USB/DC ports and requires a separate paid Hub D1 accessory, which some feel is overpriced for what it offers. [Apex 300 + B300K Β· 3 entries]
- Multiple sources note the extreme weight/bulk of the stacked Apex 300 + B300K system, making 'portable' a stretch despite handles/trolley options. [Apex 300 + B300K Β· 2 entries]
- Reviewers praise fast recharge and the system's ability to genuinely replace a generator for home backup and heavy loads like washers/dryers. [Apex 300 + B300K Β· 4 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 Β· 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 Β· 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 Β· 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 Β· 2 entries]
- A1
βThe Apex 300 doesn't have USB ports, DC ports, or much of anything beyond its six AC plugs and high-voltage connectors.β
thesolarlab.com β Bluetti Apex 300 Review: Cheap, Practical Home Backup? Β· unknown (2025/2026) Β· [mixed]
- A2
βThat Bluetti D1 Power Hub that gives you your DC and USB ports costs about $300, which is a steep price for what you're getting.β
thesolarlab.com β Bluetti Apex 300 Review: Cheap, Practical Home Backup? Β· unknown (2025/2026) Β· [negative]
- A4
βIt's one of the few systems I've tested that feels like it could genuinely replace a generator, without the noise, fumes, or maintenance.β
techspective.net β Bluetti Apex 300 with B300K Review Β· 2025-09-21 Β· [positive]
- A9
βResults: 1 wash took about 1 hour and drained the Apex from 100% down to 65%.β
digitalreviews.net β Bluetti Apex 300 Power Station Tests (Australia) Part II Β· 2025-09 Β· [positive]
- A10
βJust for fun we then turned on our heat pump dryer to see that over 1Β½ hours it would further drain it down to 20%.β
digitalreviews.net β Bluetti Apex 300 Power Station Tests (Australia) Part II Β· 2025-09 Β· [mixed]
- A12
βDuring my testing, the recharge speed was astonishing. In under an hour, I had a system ready to go again.β
thesolarpit.com β Bluetti Apex 300 Review Β· 2025-10-28 Β· [positive]
- A14
βAs will you: it weighs in at 38kg, and is probably much too big and heavy for most people to carry alone.β
trustedreviews.com β Bluetti Apex 300 Review Β· 2025-10-10 Β· [negative]
- A15
βBLUETTI spec table for the Apex 300: four 20 A AC outlets, one NEMA TT-30R (120 V, 30 A) and one NEMA 14-50R (120/240 V, 50 A), 3,840 W max in total; the two 100 W USB-C, two USB-A and 12 V ports require the Hub D1, sold separately.β
bluettipower.com β Apex 300 tech specs (checked 2026-10-04) Β· 2026-10-04 Β· [mixed]
- B2
βSome units sound like small jet engines under load, but the Apex 300's fans are relatively tame.β
Techspective β "Bluetti Apex 300 with B300K Review" Β· 2025-09 Β· [positive]
- B3
βThe Apex 300 have some major charging problems... When the units are charging from the grid they charge at different rates and not together.β
DIY Solar Power Forum β "Bluetti Apex 300 problems" Β· 2025-09 Β· [negative]
- B7
βI 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...β
BLUETTI Community β "Apex 300 stuck in Backup mode after last firmware update" Β· 2025-11 Β· [negative]
- B9
βAfter the update completed, the charging stopped and I received Error 004... I have error E004 Inverter Output Failure.β
BLUETTI Community β "Error E004 Apex 300" Β· 2025-11 Β· [negative]
- B11
βit's so heavy I can hardly carry it more than a few feet at a time and have been unable to lift it onto a table.β
T3 β "Bluetti Apex 300 review: transform your off-grid life" Β· 2025-11 Β· [negative]
- B13
βFan noise remains even, with no distracting pitch or rattle. This makes the Apex 300 usable near sleeping areas or indoor workspaces without disturbance.β
Yanko Design β "BLUETTI Apex 300 Review" Β· 2025-05 Β· [positive]
Research compiled October 25, 2026.
Who Should Buy Which
Buy the Apex 300 + B300K if youβ¦
- βYou want into the Apex 300 platform at $2,599 and can add a battery later if you outgrow it.
- βYour hardest days stay well inside 5,529.6Wh, like a one-night blackout or a workday off the grid.
Buy the Apex 300 + B500K if youβ¦
- βIt runs every day, in a van or a cabin, where the smaller build finishes a full day nearly empty.
- βYour outages can reach a third night.
- βYou want the lower cost per watt-hour and per lifetime kWh, and 34 more pounds doesn't matter on a unit that stays put.
If neither fits
If your outages are short and your loads are a fridge and some lights, both of these are a lot of battery. A single all-in-one unit in the two to three kilowatt-hour range covers that for far less money and weight.
The Bottom Line
Buy the Apex 300 with the B500K. It costs $700 more, and that money buys capacity at a better rate than the smaller build charges. It's the one that finishes a hard day with real reserve and gets through a third blackout night.
The B300K build is the right call when your loads stay well inside it and the lower $2,599 entry price matters more. Everything else is the same machine, down to the fans.
Frequently Asked Questions
Answers drawn from the spec record and cited owner research.
Apex 300 with B300K or B500K: which battery should I get?
For most buyers, the B500K. It costs $700 more, holds 2,355.2Wh more, and is cheaper per watt-hour and per lifetime kWh, $0.07 against $0.08.
Is the extra $700 for the B500K actually worth it?
If you use it daily or through long outages, yes. On a modeled 24-hour van-life day the B300K build finishes with 15Wh left, while the B500K keeps 2,017Wh. For occasional one-night outages, the B300K build is already plenty.
How much heavier is the B500K build?
About 34 lbs: 183 lbs against 148.8. Both are modular stacks moved one box at a time, and a reviewer says the bare base alone is too heavy for most people to carry, so both builds are installs rather than carry-alongs.
Do both builds support the same output and charging?
Yes. Everything except the battery is the same Apex 300: 3,840W continuous output, 2,400W of solar input and a UPS switchover rated at no more than 10ms. The bigger pack takes longer to fill at the same input. BLUETTI publishes no surge figure above the continuous rating. Its 7,680W Power Lifting figure applies to resistive loads such as heaters.
Related buying guides
Where to buy
BLUETTI Apex 300 + B300K
$2,599.00
$2,599.00 Β· direct from BLUETTI
Last checked 28 days ago. Prices move β check before you buy.
BLUETTI Apex 300 + B500KPick
$3,299.00
$3,299.00 Β· direct from BLUETTI
Last checked 28 days ago. Prices move β check before you buy.
Prices may vary by retailer and are subject to change.