BLUETTI Apex 300 + B500K vs BLUETTI EP500Pro

45dB is about as loud as a running refrigerator. It is BLUETTI's own rating rather than a reading on a shared bench — makers differ on whether they quote a best case or a figure under load, so treat it as a starting point rather than what you would hear at a bedside. For most people, fan noise around 45dB and up is where sleep starts to suffer.

The EP500Pro is sealed at 5,120Wh — fine if that covers you, but it's the ceiling. By contrast the Apex 300 + B500K can add expansion batteries, though the first thing it has over the EP500Pro is its own 7,885Wh base — expansion is the step after that, for the buyer who would outgrow 7,885Wh as well.

The Apex 300 + B500K has BLUETTI's Power Lifting mode, which runs a resistive appliance rated up to 7,680W from its 3,840W inverter. It does that by delivering less power than the appliance asks for, not more than the inverter has: the heater still works, it just heats more slowly. Two things follow. BLUETTI scopes the mode to purely resistive loads — a heater, a kettle, an incandescent lamp — so it does nothing for a fridge compressor, a pump or a power tool, and this record publishes no surge figure at all, so read the mode as a resistive-load feature rather than as starting ability. And it is not a reason to size down, because running a load that big from 7,885Wh is a short session either way. Genuinely useful if a heater or a kettle is why you're buying; beside the point otherwise. Our record for the EP500Pro carries no Power Lifting figure, only a 6,000W surge peak, which is a different rating, so check BLUETTI's own spec sheet before reading this as something the EP500Pro lacks.

Both list a UPS mode, at different rated speeds. The Apex 300 + B500K is rated ≤10ms — quick enough on paper that desktop PCs and routers should ride through, treating that as the rating it is. The EP500Pro is rated ≤20ms — fine on paper for routers and most electronics; the fussiest PC power supplies sit right at this line. If a computer with unsaved work is the thing being protected, the stated class is worth the attention; nothing here is a lab result.

Both units carry the same 5-year warranty, so coverage isn't a tiebreaker here. Both figures are maximums rather than guarantees — they depend on buying direct from BLUETTI or registering the unit, since reseller purchases carry a shorter term.

The Apex 300 + B500K is rated for 6,000 cycles vs 3,500. In real life: at daily use, that's 16.4 vs 9.6 years. At weekend use (twice a week), it's 58 vs 34 years. One caution reading years across different sizes: a cycle is 7,885Wh on the Apex 300 + B500K and 5,120Wh on the EP500Pro, so count lifetime energy — roughly 47,309 kWh against 17,920 kWh over the rated life. After hitting the cycle limit, the battery doesn't die — it drops to ~80% of original capacity, which is still very usable.

The Apex 300 + B500K publishes its noise level (45dB); the EP500Pro doesn't publish one. That isn't evidence the EP500Pro is louder — it means there's no figure to hold it to, and no way to compare the two on this without hearing them. If you're buying for a bedroom, a CPAP, or an apartment, treat the Apex 300 + B500K's 45dB as the only published number on the table — a spec-sheet figure, not a measurement — and look for hands-on reports of the EP500Pro before deciding.