Bluetti AC300 + B300

AC300-B300

For serious whole-home backup buyers only.

The BLUETTI AC300 + B300 is a modular whole-home backup system that pairs a 3,000W pure sine wave inverter module with the 3,072Wh B300 LiFePO4 expansion battery. Uniquely in BLUETTI's lineup, the AC300 inverter carries no onboard cells — every watt of stored energy comes from swappable B300 packs you can stack four-deep for 12,288Wh, or push to 24,576Wh across two AC300s and eight B300s using the Fusion Box Pro. With 5,400W of combined charging input, full wall recharge in roughly 1.5 hours, and a built-in 24/7 UPS mode that kicks in automatically when paired with the BLUETTI Smart Home Panel, the system is engineered for stationary home backup rather than grab-and-go portability — fully assembled it weighs about 125 lb, so it lives where you set it. The trade-off is real: this isn't a unit you'll haul to a campsite, and the modular design means a higher up-front cost than an all-in-one of comparable capacity. But for buyers who want to start with one battery and scale toward whole-home coverage as budget and needs grow, the AC300 + B300 remains one of the most expandable, future-proof platforms in its class.