Bluetti AC300 + B300 Review

Bluetti AC300 + B300: Modular Home Backup Done Right

The Bluetti AC300 + B300 system takes a different approach from competitors like the EcoFlow Delta Pro and Goal Zero Yeti 3000X. Instead of a self-contained unit, Bluetti separates the inverter (AC300) from the battery (B300) — a modular design that enables up to four B300 batteries to connect to a single AC300 inverter, scaling from 3,072Wh to 12,288Wh without replacing any components.

System Architecture

The AC300 is a 3,000W pure sine wave inverter with dual AC inputs, solar input (up to 2,400W), and full monitoring capability. It contains no battery itself. The B300 is a 3,072Wh LFP battery pack rated for 3,500+ cycles. Together they form the base system; adding a second, third, or fourth B300 expands capacity linearly.

This separation has practical advantages. If the inverter fails after five years, you replace only the AC300 — not the batteries. If you want more storage, add a B300 without replacing the inverter. The modular approach makes long-term upgrade economics significantly better than integrated competitors.

3,000W Output: What It Runs

The AC300 delivers 3,000W continuous with 6,000W surge capacity. In practice this means: refrigerator, freezer, microwave, lighting, router, and phone charging simultaneously — covering the essential circuits most homeowners care about during an outage. The 6,000W surge handles the starting current of large motor-driven appliances like air conditioners and washing machines without tripping.

24/7 UPS Capability

The AC300 + B300 supports 24/7 UPS operation with under 20ms switchover — suitable for protecting computers, NAS drives, and other sensitive equipment from power interruptions. In UPS mode, the system continuously monitors mains power and switches to battery instantly if supply fails. This dual-role capability (portable power station + whole-home UPS) is rare at this price point.

Solar Charging

Maximum solar input is 2,400W via the AC300's dual MPPT inputs — accepting panels from 12-150V. With three 400W panels (1,200W input), a single B300 can be fully recharged in approximately 2.5 hours of peak sunlight. With the maximum 2,400W solar array, charging is faster still. The system can also accept simultaneous AC and solar input, combining both sources to minimise charge time. For optimal performance, pairing with high-efficiency panels like SunPower Maxeon maximizes energy harvest.

Comparison: AC300+B300 vs EcoFlow Delta Pro

Spec	Bluetti AC300+B300	EcoFlow Delta Pro
Base capacity	3,072Wh	3,600Wh
Max capacity	12,288Wh (4×B300)	25,000Wh
AC output	3,000W (6,000W surge)	3,600W (7,200W surge)
Solar input	2,400W	1,600W
Battery cycles	3,500+	3,500+
Modular	Yes - separate inverter/battery	No - integrated unit
Price (base)	$3,499	$3,499

The EcoFlow Delta Pro wins on base capacity and AC output. The Bluetti AC300+B300 wins on solar input (2,400W vs 1,600W) and modular design flexibility. At identical pricing, the choice comes down to priorities: EcoFlow for maximum output and ecosystem, Bluetti for solar charging speed and long-term upgrade flexibility. For a detailed comparison of both systems, see our best solar generators for home backup guide.

Final Score: 8.7/10

The Bluetti AC300+B300 is a serious home backup system that earns its high rating through genuine engineering innovation — the modular design solves real problems with long-term ownership that integrated units cannot. The 2,400W solar input leads the class. For buyers planning a whole-home backup system they intend to expand over time, the Bluetti modular approach is arguably more future-proof than EcoFlow's competing system.