EG4 has been making serious waves in the solar and battery space for quite a while now. We’ve reviewed plenty of their inverters and batteries, with most of them impressing us. When it comes to the new EG4 100Ah WallMount Battery, we think they continue this pattern of offering well-made and practical products at fair prices.
Basically, this unit is a repackaged EG4 LL Server Rack Battery, but presented inside a compact, wall-mountable system. While it may not seem ground-breaking at first glance, it fills a niche that many DIY solar users and off-grid enthusiasts have been asking for: a smaller, lightweight, lithium iron phosphate battery that doesn’t compromise on performance.
We spent several days using and testing this 100Ah WallMount Battery, so let’s see if it lives up to the hype.
Before we dive into the nitty-gritty, here’s a quick breakdown of the specifications for this little unit:
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At just 108 pounds, the EG4 100Ah WallMount Battery is surprisingly portable. It’s still 108 pounds, but it’s almost small enough that you could hoist it up on your back like a backpack. If you’re planning to install it in a remote location, this compact and portable design could be hugely beneficial.
Plus, with a capacity of 5,120Wh (5.12kWh) and a 100A continuous output rating, it offers a sweet spot of power and portability that’s rare in the lithium battery world. Most wall mounted batteries have a much higher capacity, which also means they weigh significantly more and are pretty difficult for a single person to lift.
The overall construction also feels solid. The casing is a single-piece enclosure that’s smooth, clean, and free of protruding screws or sharp edges. This makes it ideal for tight spaces and simplified installations.
The included mounting brackets are also really sturdy, and you get built-in handles on the side that are surprisingly comfortable. The rubber feet on the bottom also work well for temporary setups, and a breaker with a BMS switch is conveniently located on the side of the unit.
The top of the battery houses the terminals, DIP switches, and communication ports, while inside you'll find temperature sensors and fire arrestors, which contribute to the battery’s UL certification. The safety features are fully integrated, which simplifies the install process and adds peace of mind for those operating in off-grid or extreme environments.
When we brought this unit into the Solar Lab, we weren’t expecting any major surprises, but it actually exceeded our expectations in a few key areas.
Efficiency testing showed that the unit delivered 100% efficiency, which is what we expect from any quality lithium battery, but it’s still worth highlighting. It also surged to 125A for 10 seconds without issue and handled sustained 100A discharge loads comfortably.
The Battery Management System (BMS) worked exactly as intended, shutting down the battery when operating outside of safe temperature and voltage ranges. To test its cold-weather resilience, we placed the battery in a freezer and brought it down to -4°F (-20°C).
As it should, the BMS refused to allow the battery to operate at this unsafe temperature, preventing both charging and discharging. Once we got it back up to safe temperatures, it resumed normal operation.
When you combine it with its sturdy exterior build, this kind of temperature protection makes sure it’s going to be a solid choice for off-grid setups, even in cold climates where the insulation is minimal.
The simplicity of this battery is one of its biggest strengths. With integrated handles, a clean bracket system, and a single housing, it’s easy to transport and mount. Whether you're setting up a permanent installation in a cabin, or using it in a temporary shelter or mobile environment, the 100Ah WallMount is a flexible, plug-and-play solution.
It’s especially attractive for users transitioning from lead-acid systems or portable power stations. The entry-level price and straightforward design make it ideal for solar beginners who want to dip their toes into lithium battery storage without committing to a full server rack system.
EG4 promotes this battery as a perfect pairing with their EG4 6000XP Inverter, which is one of the smallest inverters they offer that’s capable of starting heavy-duty loads like compressors. And while the two products are compatible, the pairing does have limitations.
During testing, the 6000XP could start our compressor, but one of these 100Ah batteries wasn’t enough to supply the surge current needed for that kind of load. So, while you can pair the WallMount Battery with the 6000XP, to get full performance, you’d realistically need at least two of them.
This raises an important consideration: if you know you need more capacity right away, it may make more sense economically to go straight to a larger EG4 wall mount battery, like the EG4 PowerPro WallMount Battery, or to an EG4 server rack system, rather than piecing together multiple small units.
That said, if mobility or installation constraints are a factor (such as limited space, narrow doorways, or remote access), these smaller batteries make perfect sense.
One of the best use cases for this battery is in small, off-grid cabins, mobile setups, and situations where weight and space are a concern. For example, if you're hauling batteries into a cabin via an ATV or small boat, large wall-mounted units may be too bulky or heavy.
This unit also shines when used to cleaning up messy setups. Even somewhere like Josh’s tiny home setup could benefit from a unit like this, as it could work as a replacement for the multiple EcoFlow DELTA Pro units and expansion batteries he currently has cluttering the floor.
Basically, wall-mounting a clean, consolidated unit like this frees up space and simplifies all of your wiring.
As you can probably guess by now, we found plenty of things to like about this little unit:
It passed all of our performance and environmental tests. From surge handling and cold weather operation to checking the BMS protection, everything worked exactly as EG4 said it would.
Thanks to the built-in temperature sensors and fire arrestors, it also has genuine UL certification. While being UL listed is important in some areas, specifically California, it’s also just great for peace of mind knowing your battery is safe and code compliant.
At 108 lbs, it’s still pretty heavy, but it’s light enough for solo installs. Even if you have it sitting on the ground, the footprint is small enough that you’re not going to be eating up too much floor space.
One of the biggest standout features of the EG4 100Ah WallMount battery is its price point. At around $1,500, it’s easily one of the most affordable wall-mounted lithium batteries on the market.
You're getting a name-brand battery with real certifications, a built-in BMS, and a reasonably high 5.12kWh of usable capacity at a cost that's hard to beat. Whether you’re a budget-conscious homeowner, you're just trying to build a system piece by piece, or you’re coming from lead-acid batteries and want to transition into lithium without a steep learning curve, it just fits the niche perfectly.
Since you can run multiple units in parallel, and it works seamlessly with the EG4 6000XP, the EG4 18kPV and even the newer FlexBOSS 18, it’s super easy to scale your system over time.
Scalability isn’t just great for long-term usability, it’s also really nice for those who have limited budget right now, but might want to pick up more batteries in the future when their budget opens up.
Suitable for cabins, sheds, a tiny home, workshop, or any remote setups where space is tight, but you need a semi-permanent battery storage.
While it’s undoubtedly a really solid battery, it’s not without its faults. Here’s a few of the gripes we had:
The display screen is pretty small and somewhat difficult to read, especially in low light. Even the display buttons feel stiff and low-quality, especially in cold conditions where they feel crackly and brittle. It’s meant to have a build that makes it practical for more rugged, off-grid environments, but in places with poor insulation, this could be an issue over time.
Despite being advertised as a match for the 6000XP inverter, a single 100Ah battery can’t deliver the surge power needed for large appliances. Two or more units are needed to take full advantage of that inverter.
If you already know you’ll need 10kWh or more of storage capacity, it’s more cost-effective to go straight to a larger wall mounted unit or server rack battery setup.
The EG4 100Ah WallMount Battery is a well-built, reliable, and versatile option for those looking for a lightweight, modular lithium battery.
It’s not going to be the right option for every system, especially if you're planning to power large loads or want the cleanest $/kWh ratio, but as a starter unit, or for use in tight, mobile, or off-grid environments, it’s an incredibly appealing choice.
We would confidently recommend this unit to a friend, or really anyone who is getting into solar or off-grid living for the first time.
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