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BLUETTI Apex 300 B300K review: Our specification-led assessment covers battery capacity, inverter power, solar charging, expansion and value for US home backup.
Verdict: The BLUETTI Apex 300 with one B300K battery offers 5,529.6Wh of nominal storage and 3,840W AC output, making it a serious contender for home emergency backup, cabins and larger RVs. The appeal is its expandable capacity and high output; the drawbacks are weight, price and the extra hardware needed for some use cases.
BLUETTI Apex 300 B300K review: key specifications
| Feature | Specification (US version) |
|---|---|
| Battery | 5,529.6Wh total: Apex 300 2,764.8Wh + B300K 2,764.8Wh |
| Continuous AC output | 3,840W, pure sine wave |
| Chemistry | LiFePO4 |
| Solar input | Two MPPT inputs, up to 1,200W each |
| AC sockets | Four 20A outlets, TT-30R and NEMA 14-50R (combined 3,840W limit) |
| App | Wi-Fi and Bluetooth |
| Warranty | Five years, per BLUETTI US |
| Advertised bundle price | $2,599, subject to change |
Source: BLUETTI’s US product listing and technical specifications. Verify current configuration, pricing and availability before purchase.
Who is it for?
This system suits homeowners wanting to keep key appliances running during an outage, as well as off-grid users with larger energy requirements. It is excessive for phone charging or a simple weekend camping trip. The Apex 300 base unit weighs approximately 83.8lb (38kg) even before adding the B300K, so this is transportable equipment rather than something most people will carry casually.
How long will 5.53kWh last?
Nominal capacity is not the same as usable AC energy. Assuming 85% usable AC energy for an illustrative calculation gives roughly 4,700Wh; this is an estimate, not a measured test result. At a constant 100W load that is about 47 hours; 200W about 23.5 hours; 500W about 9.4 hours; and 1,000W about 4.7 hours. Real results vary with conversion losses, inverter idle consumption, temperatures and appliance duty cycles. Refrigerators in particular cycle on and off, so use measured daily kWh where possible. Try our portable power calculator or read our refrigerator backup guide.
Four major advantages
1. Expansion without replacing the main unit
The B300K doubles nominal capacity from 2.76kWh to 5.53kWh. BLUETTI lists support for up to six compatible expansion batteries per Apex 300, with more complex multi-unit setups supporting larger systems. Check compatibility and accessories for the exact configuration.
2. Strong 3,840W output
The pure sine-wave inverter can handle many household appliances within the combined output rating and individual outlet limits. Its US 120V/240V capabilities are useful for certain backup arrangements, but connecting a power station to household circuits requires suitable transfer equipment and potentially a qualified electrician. Never backfeed a home through an ordinary outlet.
3. Solar recharging
Two 1,200W MPPT inputs give up to 2,400W of direct solar input in suitable conditions. Actual charging depends on sun, panel orientation, temperature and electrical compatibility. Our solar charging guide explains the basics.
4. LiFePO4 longevity
BLUETTI specifies more than 6,000 cycles to 80% capacity for the Apex 300. This is a manufacturer rating under defined conditions, not proof of a particular lifespan in every home.
What we don’t like
- Weight: the 83.8lb base unit plus expansion battery is not lightweight.
- Cost: $2,599 is a substantial investment and may be unnecessary for small loads.
- Accessories: BLUETTI states that USB-A, USB-C and certain DC outputs require an optional Hub D1. Check what is included.
- Not a turnkey whole-home installation: additional connection equipment may be needed.
- Usable energy is less than nominal: budget for inverter and charging losses.
Value for money
At the advertised $2,599 price, the bundle costs approximately $0.47 per nominal Wh. That is a useful comparison point, but not a complete value calculation: inverter power, warranty, accessories, expandability and support matter too. If you only need a router, lights and a compact fridge for short outages, consider a smaller system. If you need multi-day flexibility and future expansion, the Apex 300 + B300K is more compelling.
Frequently asked questions
Can it run a refrigerator?
Usually yes if the appliance’s running and starting requirements are within the system’s limits. Runtime depends on actual energy consumption and other connected loads.
Does adding the B300K increase inverter output?
No. Adding the battery primarily increases stored energy and runtime; the single Apex 300 unit’s standard AC output remains 3,840W.
Can it charge from solar?
Yes. It supports two MPPT solar inputs rated up to 1,200W each, subject to voltage and current limits.
Have we physically tested it?
No. This review evaluates manufacturer documentation, electrical specifications and transparent runtime estimates rather than claiming hands-on experience.
Final verdict
Recommended for the right buyer: the Apex 300 + B300K is a high-capacity, expandable alternative to a smaller portable station, particularly for home backup. Just confirm your daily loads, budget for the full system and plan safe electrical connections before buying.
Further reading: Best portable power stations for home backup and LiFePO4 vs lithium-ion.