BLUETTI AC500 vs AC300+B300 vs Apex 300
Compare BLUETTI modular systems by inverter, battery dependency, voltage configuration, charging inputs, and transfer limitations.
AC500, AC300+B300, and Apex 300 are modular or configuration-sensitive BLUETTI systems. Their headline output and stored capacity are not directly comparable until you know which inverter, battery pack, region, outlet mode, and accessories are present. This comparison uses US-facing product and manual sources where specified; the AC500 manual also includes non-US rows that must stay separate from the US product page.
Compare the system boundaries
| System | Inverter / output | Battery dependency and stated expansion | Important mode boundary |
|---|---|---|---|
| AC500 | 5,000 W; 10,000 W surge on the US page | Cannot operate alone; one to six B300S are described, with 3,072–18,432 Wh nominal storage in the manual | 4,500 W with one B300S; 5,000 W requires a battery on each expansion port |
| AC300+B300 | 3,000 W; up to 6,000 W stated surge | AC300 works with B300 packs; the manual states support for up to four | US 100–120 V split-phase requires two systems and specified fusion equipment |
| Apex 300 | 3,840 W maximum; selectable 120 V or 240 V | Base 2,764.8 Wh; up to six B300K, with 19,353.6 Wh stated maximum system capacity | Outlet limits and UPS switching depend on voltage, outlet, and AC-input condition |
Nominal capacity represents battery storage, not energy measured at a load. The systems differ in battery generation and connection paths. Verify the exact battery label, cable, firmware, and regional manual rather than treating all BLUETTI expansion batteries as interchangeable.
Output topology is not the same
The US AC500 page lists 120 V outlets including 20 A receptacles, a 30 A L14-30, a 30 A TT-30, and a 50 A NEMA 14-50, with 5,000 W total output. It describes split-phase bonding and says AC500 cannot be used alone. The AC500 manual’s 220–240 V rows describe other regional variants; they are not a second output mode for every US unit.
The AC300 manual lists 3,000 W output and regional configurations for Japan, the US, Europe/UK, and Australia. Its 100–120 V split-phase arrangement needs two AC300+B300 systems and specified fusion equipment. The manual warns that incorrect phase connections can damage equipment and says a certified technician is required for a sub-panel system. Those statements define a configuration and safety boundary; this comparison does not explain household wiring.
The Apex 300 manual describes selectable 120 V or 240 V output. Its four 5-20R outlets have different per-port limits at the two voltages, and paired 240 V outlets have an additional combined ceiling. The TT-30R and 14-50R also have mode-specific discharge and bypass limits. A 3,840 W system figure does not replace the outlet and mode table.
Charging and batteries
The AC500 manual lists two PV inputs, each up to 1,500 W and 12–150 V DC at 15 A, while the US product page specifies the battery-dependent output boundary. The AC300 manual lists two 12–150 V, 12 A inputs, up to 1,200 W each. The Apex 300 manual lists two 12–60 V, 20 A, 1,200 W inputs and different combined charging ceilings depending on battery configuration. Panel wattage alone is not enough: confirm total voltage, current, connector, and approved cable for each input.
The Apex manual names B300K expansion; the other systems have their own B300/B300S paths. An expansion battery adds stored capacity, but does not automatically increase inverter output. Confirm the pack count and distribution that the exact manual allows before relying on a published maximum.
UPS claims depend on configuration
The AC500 manual states a 20 ms UPS switching value. The AC300 manual describes several UPS modes but does not establish a no-break result for a particular device. The Apex 300 manual describes 20 ms switching at 120 V; its 0 ms statement applies only to two left outlets in 240 V mode while connected to grid through 15 A AC input. It also warns against use for servers or workstations requiring high-performance UPS. None of these claims is an independent transfer test or medical-device approval.
For every system, verify the device’s voltage, startup demand, output arrangement, and transfer tolerance. Fixed transfer equipment and sub-panel connections require current manufacturer instructions and qualified local assessment. The 120/240 V guide compares output arrangements; the UPS guide separates switching claims from device behavior.