Bluetti AC300 + B300K Review: A Match Made in Emergency Preparedness Heaven

It may be large and cumbersome, but the BLUETTI AC300 and B300K Home Battery Backup System is worth all the effort it takes to find a place for it in your home. It has many uses, but it’s best used as a backup power source.

BLUETTI AC300 and B300K Modular Power Stations

9 / 10

$1899 $2499 Save $600

BLUETTI succeeds in creating an expandable whole home battery backup system that can deliver the power needed to stand in during emergencies. It’s also versatile enough to be taken on the road, be it an outdoor adventure or to an electricity-free job site.

Pros Expandable to become a viable whole-home backup Fast-charge in just over 1.5 hours Very easy to turn on and use Instant on emerency power supply

Cons Lower capacity than previous B300 model No USB-C on B300K Inverter is virtually useless alone Cumbersome and heavy

$1899 at Bluetti $2999 at Amazon

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Price and Availability

BLUETTI’s AC300 and B300K modular systems are available via the official website for $2,499. Multiple AC300 and B300K bundles are available with two, three, and four expansion batteries included for $3,799, $4,999, and $6,499, respectively. Additional 2,764.8Wh expansion batteries can also be purchased separately for $1,409, while another AC300 inverter costs $1,399.

The AC300 and B300K By the Numbers

Mark LoProto / How-to Geek

Though I’ve had some time with BLUETTI products before, having reviewed the AC200L and AC200MAX power stations, the AC300 is the first battery-free inverter I've tried that requires an external battery, the most recent being the B300K, to work. It’s a large and cumbersome system, but that’s not without reason. The B300K has a capacity of 2,764.8Wh, which is about 700Wh more than the AC200L or AC200MAX. The AC300 inverter is also capable of producing 3,000W 120V AC power, which surpasses the other models.

While that’s a decent amount of power, that’s not where this setup ends if you need more. BLUETTI systems are known for being expandable, but this modular system feels almost limitless in what it can do. Not only is the AC300 capable of connecting to four B300K batteries for a capacity increase of over 11,000Wh, but that can be duplicated for even more power or split-phase use. In total, if you have around $10,000 to spare, you can build a system that can generate 6,000W and store a little more than 22,000Wh.

For reference, let’s say you have a refrigerator that runs consistently at 500W. In a perfect scenario where the power system is most efficient, a full 22,000Wh setup would power the refrigerator for 44 hours.

As far as battery backup systems go, that’s pretty significant. Even a single AC300 and the B300 battery, an older version of the B300K with a 3,000Wh capacity, can be a lifesaver, as I unexpectedly learned in mid-August 2024.

Ports Aplenty

Mark LoProto / How-to Geek

One thing you’re not short on with the AC300 is output ports. There are seven AC outlets, including six 120V/20A and one 120V/30A. You also have a 12V/30 and 24V/10A DC outlet and two 5V/3A and 18W USB-A ports. BLUETTI did sneak in a 100W USB-C outlet and two 15W wireless charging pads to cover all bases.

The most demanding (and most accessible) power-hungry device I have on hand is a vacuum. With a constant power draw while running, it gives a good indication of how steady the modular system’s output is. At its highest power consumption, the vacuum drew 775W. Over 15 minutes of runtime, the battery dipped 2% and the fan didn't kick on, suggesting the battery won't overheat and you won't hear it often.

Mark LoProto / How-to Geek

Best of all, you can have plugs in the AC, DC, and USB ports and dictate which are active either via LCD screen on the inverter or using BLUETTI’s app. This ensures you’re using only the power you need without constantly unplugging devices.

Speaking of the app, there’s not a ton to say. It does everything the AC300’s touchscreen does while also generating usage reports.

Mark LoProto / How-to Geek

June 2024 kicked off a record-setting Las Vegas summer that experienced over 80 100-degree Fahrenheit days. As much as I enjoyed running my air conditioner at a brisk 70 degrees daily, that was abruptly taken from me during a temperature spike that knocked out my power. It didn’t take long for the pangs of having no power to hit, but thankfully, before sending the two B300K batteries, BLUETTI had provided the AC300 and a B300 3,000Wh battery a few weeks prior.

I will admit, the modular system wasn’t the most efficient way to power parts of my home, only because it wasn't hardwired into my circuit breaker and the battery was cumbersome to have to move back and forth between appliances. I bounced from running the fridge to the water heater to fans for the better part of a day, just trying to sustain comfort and minimize food loss without knowing when the power would kick back on. During this chaos, I began to understand the primary purpose of the modular system. After receiving the B300K, I ran a simulation of the same power outage and no difference in performance.

If I didn’t live in a rental and could rewire the house to my liking, I’d purchase BLUETTI’s AC300 Home Integration Kit and set my home up to run on the modular system the moment the power turns off. The Split Phase Fusion Box is another must, particularly if you want two AC300s running for 240V operation.

Together, the inverter and battery are made to be an uninterruptible power supply (UPS) that activates instantly. When the power goes out, the UPS kicks on, and the inverter intelligently distributes only the wattage needed to keep key appliances running. I wish I could test the system to its maximum, but I was still quite pleased that the modular system kept parts of my home running, even if I had to lug the 65lb battery (and slightly lighter inverter) all over.

Versatile, If You Have the Space

One thing I’ve liked about BLUETTI’s other power stations is their portability. They’ve always been on the bigger side, but their capacity and output made them great for camping or job-site use. Though BLUETTI markets the AC300 and B300K combo as an option for outdoor adventures and professional use, I have to disagree. The capacity and output are perfectly fine for both scenarios. It’s the size that has me leaning toward other models for portability.

The B300K battery isn’t just heavy. It’s also fairly wide at almost 2 feet. Coupled with the inverter, which is just as long and nearly double the height, it will take up a decent amount of room. When camping or in an RV, space is a luxury, not a guarantee. I’d argue that many of BLUETTI’s portable power stations are a bit too big for such applications, but they’re more manageable than this pairing.

As for job-site use, I can see the value, especially if a property doesn’t have power. The 2,764Wh capacity could come in handy to keep rechargeable batteries powered and to run heavier machinery.

Easy and Quick Charging

Mark LoProto / How-to Geek

No matter how you use the AC300 and B300K, there’s one universal truth—charging is a breeze. As I type this, I have them routed into a standard wall outlet, drawing a consistent 1,739 to 1,741W. Marketing for the modular system promotes a 1.5-hour 100% recharge time, and that’s pretty much spot on, give or take 10 minutes. If you had a full 22,000Wh system, you’re looking at about half a day to charge each battery, which isn’t bad considering the amount of power it provides.

The system also supports solar, dual AC, and AC and solar combo charging. Unfortunately, I didn’t have a solar panel to test the charging. BLUETTI sells a 350W panel, which, if it consistently delivers 350W, would fully charge an empty battery in a little over 7 hours. Historically, I’ve found solar panels to be less efficient than advertised, and a 120W panel may give you 80 to 100W.

In a pinch, you can also charge the battery from your car. I don’t recommend it as your go-to charging solution, as it’s entirely inefficient and will take forever. The option is nice if you’re on the road and need a little boost, though.

Should You Buy the AC300 + B300K Modular System?

If I could somehow repackage the BLUETTI AC300 + B300K Modular System into something more compact and portable, my complaints would be few and far between. Any other issues that popped up, like the battery connection cables being a little tight and difficult to connect, are very easy to overlook. It’s not obnoxiously noisy, though you will hear the fan when it kicks in, and it’s very user-friendly, which is necessary for something that may keep your home powered during a blackout.

Reliable fast charging, a bounty of outputs, BLUETTI’s staple durability and mechanics, a functional companion app, and impressive expandability help soften the blow of $2,499 for just the inverter and battery. Then again, it’s tough to put a price tag on comfort and preparedness, especially if you live in an area that frequently suffers from power outages.

If I had the ability to, I would at least wire my current AC300 and BC300K modular system into my rental to ensure I’m ready for another brutal Vegas summer and the dreaded surprise power outage.

BLUETTI AC300 and B300K Modular Power Stations

9 / 10

$1899 $2499 Save $600

BLUETTI succeeds in creating an expandable whole home battery backup system that can deliver the power needed to stand in during emergencies. It’s also versatile enough to be taken on the road, be it an outdoor adventure or to an electricity-free job site.

$1899 at Bluetti $2999 at Amazon