Bluetti EP900 Home Battery Backup Review: A Powerful Home Backup You Can Install Yourself

Bluetti is no stranger to batteries. As a company mostly known for its portable power stations and solar generators, the logical next step is a whole home backup solution. This is where the EP900 Home Battery Backup comes in. 

The “EP900” is actually a powerful 9-kW inverter. This inverter sits on top of several small B500 batteries, able to store about 5 kWh each. The system itself almost looks like a battery tower, with a bunch of little gray boxes all stacked on top of each other. This is a refreshingly different aesthetic from the “garage refrigerator” look that’s popular with home batteries. 

“The most unique aspect of the EP900 is that it is an all-contained ESS [energy storage system] device,” Brian Shircliffe, a sales director of home energy storage systems at Bluetti, told CNET. “We’ve put it all in one unit.”

We did not conduct any hands-on testing for this review. Batteries are part of a complex home energy system that varies between households. Instead, this review is based on publicly available information online from Bluetii and an interview with Shircliffe. 

Here’s what you should know about Bluetti EP900 Home Battery Backup. 

What do I get with the Bluetti EP900 Home Battery Backup?

The EP900 system offers a modular design with multiple capacity options and a powerful 9-kW inverter. You’ll also get a 10-year warranty. This battery system’s round-trip efficiency and depth of discharge is lower than other batteries on the market, but it’s not terrible. We’ll talk more about specs and warranty below. 

The EP900 is compatible with new and existing solar panel systems. Or you can install it without solar panels as a standalone backup power source. Here’s a quick look at some of the specs for the Bluetti EP900.

Bluetti EP900 Home Battery Backup specs

Category	Description
Usable capacity	9 kWh, 13.5 kWh or 18 kWh
How many can I install?	Up to two EP900 systems
Round-trip efficiency	85%
Depth of discharge	90%
Continuous power output (on & off-grid)	9 kW
Battery chemistry	Lithium iron phosphate
AC- or DC-coupled?	AC
Price	$12,298 – $17,298 (prices subject to change)

System components 

The EP900 system’s design is a bit more simplistic than other batteries we’ve looked at. Bluetti did this so that if you buy the battery you’ll be able to install it on your own, Shircliffe said. If you’re tech-savvy and confident with electrical instructions, you could take the DIY approach. The best part about this is that you’d save thousands of dollars on installation costs. However, if you’d rather leave these sorts of things to professionals, there’s an option to hire an installer too. 

“This comes as a kit. Everything’s been pre-crimped and cut,” Shircliffe said. “When you order one of these, it gets drop-shipped to your house very similar to any of our other consumer products. And then it takes about 20 to 30 minutes to unbox it, maybe another 10 to 20 minutes to assemble it, plug in all the connections, hit go. And then you’ve got [an] up and running solar battery.”

The actual components are standard. You’ve got the B500 battery modules, EP900 inverter and a sub panel. The B500 battery modules store energy and get placed on the system’s base and stacked on top of each other, installed in parallel. The EP900 inverter is what converts DC electricity into AC electricity that your home can use. This gets installed on top of the battery modules, sitting as the head of the system. The entire setup should look like a tower.

There’s also the sub panel, also referred to as the critical load panel. This small box acts as a sort of middleman between your home’s main electrical panel and the battery system. The AC output is what gets wired to the critical load box, Shircliffe said. You’ll also have two inputs wired in there. One for the battery and one for the grid. These circuits go onto this separate panel so that they can be controlled and maintained separately from other circuits.  

If you choose to install the EP900 system outside, you also have the option of installing a little enclosure that goes around it. This shelter has an almost shed-like appearance, so if you don’t want people to walk by and see a battery tower, this is a good cover-up.

Capacity and modularity 

The EP900 has a modular battery design, meaning you’ll be able to upgrade your capacity in smaller increments on the same system, versus having to buy another giant battery. This also allows you a bit more wiggle room when trying to find the battery capacity that’s “just right” for your household’s energy needs. 

“Everything we do is modular,” Shircliffe said. “So let’s say a year or two later, you decide, ‘Hey, I think I do need another battery or more capacity.’ You can add to it or you can even add another device as well. So you can have up to two of these devices installed at your house.”

Capacity is determined by the amount of B500 batteries you choose to install with your system. Each B500 battery stores about 5 kWh. You can install two B500s for 9.9 kWh, three B500s for 14.9 kWh or four B500s for 19.8 kWh. If you find yourself needing more than 19.8 kWh, you can install another EP900 system for a total battery capacity of 39.6 kWh. Keep in mind that these numbers are the maximum capacity, not the usable amount. The chart below has a quick capacity breakdown.

Capacity breakdown

Number of B500 units	Maximum capacity	Usable capacity
2	9.9 kWh	About 9 kWh
3	14.9 kWh	About 13.5 kWh
4	19.8 kWh	About 18 kWh

Performance and efficiency 

The EP900 system has an impressively high power output. The higher your battery’s power output, the more of your home you’ll be able to backup during an outage. The EP900 has a continuous power output of 9 kW. Very few residential batteries on the market are this powerful. The cool part is that you’ll get all this power at any capacity size you choose with the EP900 system. Normally, this kind of power is only reserved for much larger batteries, so if it’s power you’re after, this is definitely worth considering.  

Round-trip efficiency is an area where the EP900 system is weaker. Round-trip efficiency is essentially how much electricity makes it to your battery without getting lost during the storage process. The higher your round-trip efficiency, the less electricity you’re wasting. Most home batteries nowadays have a round-trip efficiency rating of at least 90%. The EP900 has one of the lowest efficiency ratings we’ve seen, at 85%.

The battery’s depth of discharge is a bit lower than the competition. Depth of discharge is how much energy you’re able to drain from your battery’s maximum capacity without causing damage to it. The lower the depth of discharge, the less of your battery’s maximum capacity you’ll be able to use. The actual batteries of the Bluetti EP900 system are the stacked B500 batteries, each with a 90% depth of discharge. We’ve found the average depth of discharge for these types of batteries to be about 95%, making the EP900’s depth of discharge a bit lower than some of the other batteries out there.

Performance and efficiency details

Round-trip efficiency	Depth of discharge	Continuous power output (on & off-grid)
85%	90%	9 kW

Warranty

The EP900’s warranty is actually pretty good, even though it might not appear that way on the surface level. A 10-year warranty is basic for these types of batteries and is considered the industry standard. But the expected energy throughput and end-of-warranty capacity guarantee are worth your attention. The rated energy throughput per B500 battery module is 15.48 MWh, which is pretty good for a little 5 kWh. Bluetti also offers one of the higher capacity guarantees we’ve seen, at 80%. Most manufacturers will usually only guarantee up to a 70% original capacity retention.

Warranty details

Number of B500 batteries	Years covered	Energy throughput	End-of-warranty capacity guarantee
2	10	30.96 MWh	80%
3	10	46.44 MWh	80%
4	10	61.92 MWh	80%

Years: This is the length of time your battery is covered under warranty. After 10 years, your warranty expires.

Energy throughput: This is the expected amount of total energy (in megawatt-hours) that will flow through your battery during its lifetime, determined by the manufacturer. Once your battery hits its rated throughput, your warranty expires, regardless of how many years you have left of your warranty.

End-of-warranty capacity guarantee: Your battery won’t be able to retain its original capacity during its lifetime. An end-of-warranty capacity guarantee is the manufacturer’s promise that your battery will still be able to retain up to a certain percentage of its original maximum capacity by the time your warranty ends. Bluetti guarantees that your battery system will be able to retain up to 80% of its original starting capacity by the end of your warranty.

Customer support

Reading online customer reviews from a few different sources can help you get a feel for what a company’s customer service might be like. But these reviews should be taken with a grain of salt, and there’s always the possibility that some reviews are not genuine. This is the internet, after all. 

Like just about every battery manufacturer we’ve seen, Bluetti’s customer support tends to lean on the bad side. Customers on Bluetti’s Better Business Bureau page expressed a variety of concerns, mainly around the quality of customer service they received, strange shipping and return policies and experiencing issues trying to get in contact with Bluetti’s customer support line. Customers relay similar experiences on a Bluetti Trustpilot page. One of the more common complaints is not being able to get into contact with someone for customer support, as well as unreturned phone calls and emails. 

However, customer reviews on Bluetti’s United Kingdom Trustpilot page are far more positive, with most customers saying they haven’t had any issues with Bluetti’s customer service. It’s also worth noting that most Bluetti products have very positive reviews on Amazon.  

How much does the Bluetti EP900 Home Battery Backup cost?

How much you’ll pay for the EP900 system mostly depends on how much energy storage capacity you want. And since the EP900 system is shipped direct-to-consumer, there’s a certain level of price transparency that other battery manufacturers don’t have. You can easily go to Bluetti’s website to see how much the battery setup you want is going to cost. 

We found the prices we saw to be pretty fair for what you get, but also a little more expensive than other batteries of similar size. If your budget is your top priority, there are cheaper batteries on the market. A general rule of thumb to follow with battery pricing is that you can typically expect to pay somewhere between $1,000 and $2,000 per kilowatt-hour of storage.

Here are the listed prices we found on Bluetti’s website. Keep in mind that these prices are subject to change and don’t include the cost of professional installation.

Price breakdown

Number of B500 batteries	Usable capacity	Price
2	About 9 kWh	$12,298
3	About 13.5 kWh	$13,978
4	About 18 kWh	$17,298

Is the Bluetti EP900 Home Battery Backup my best choice?

There’s no definitive “best battery.” Because everyone’s house and energy needs are different, there isn’t one battery that is going to be the best fit for every home. The best battery for you is the one that aligns with your energy needs and what you’re planning to use it for. If a modular battery design, high power output and a good warranty are your top priorities, then the Bluetti EP900 might be a good match for you, especially if you feel confident enough to install the system yourself. This is one of the least efficient home battery systems that we’ve seen on the market. But that might not matter to you.

Don’t limit yourself to just one battery, no matter how good it looks. The battery market is vast, and most installers can install more than one brand of battery. We recommend looking at a few batteries from installers in your area before making a final decision. Getting multiple quotes from installers might save you thousands of dollars too. 

Frequently asked questions