Server Rack vs. Wall-Mount Batteries Buyer's Guide: Which Is Best for You?
Whenever you’re setting up a new solar power system, choosing the right type of batteries is going to be an important decision, but it can also be a bit of a puzzle.
Two common options you’ll come across are server rack batteries and wall-mount batteries. While they’re both designed to store power, the variations in design, usability, and storage capacity can make all the difference if you’re trying to choose the best fit for your system. To help you choose the right type of batteries for your needs, we’re diving into a head-to-head comparison of server rack batteries and wall-mount batteries.
While most batteries in these two categories are similar to others in their same category, for the purposes of this guide, we’re going to be using the EG4 LL Server Rack Battery and the EG4 PowerPro Wall Mount Battery as our two examples. Both are really popular, high-quality options, so they’ll work well as model units for our comparisons.
So, let’s break down the pros, cons, and best applications for each type of battery, so you can make an informed choice!
Server Rack Batteries: Compact, Modular, and Versatile
Let’s start with a quick overview of what server rack batteries are. In general, a server rack battery will have a storage capacity of about 5,000Wh. As the name implies, the design is similar to that of a stackable computer server, meaning the batteries are made to sit in a framework on top of each other.
Whether you use a cabinet that was specifically designed to hold server rack batteries, like we use here at The Solar Lab, or you just go for a more basic shelf, they’re adaptable to various setups and offer some flexible, long-term advantages.
Pros of Server Rack Batteries
Now that you have a basic idea of what a server rack battery is, let’s take a look at some of the main advantages of using them for solar applications:
The Modular and Expandable Design:
One of the standout benefits of choosing server rack batteries is their modular design. For example, the EG4 Cabinet we’re using would allow you to start small—with just one or two server rack batteries—and then add more batteries over time as your energy needs or budget grows. A typical server rack cabinet can hold up to six batteries, giving you around 30kWh of storage capacity when it is fully loaded.
Easily Serviceable and Potential for Mixing-and-Matching:
Going with server rack batteries gives you the option to have really flexible configurations. For example, you could mix different server rack battery models, which is actually something we do ourselves here at The Solar Lab. Rather than just using one type of server rack battery, our cabinet contains both EG4 LL and EG4 V2 Life Power 4 batteries, giving us more options for customization.
Even better than that, if one battery in your cabinet fails, you won’t lose power across the whole system. You can swap out, repair, or fully replace individual batteries when you need to, keeping the rest of the system running smoothly. On the other hand, with one large wall-mount battery, if it fails, it fails—you lose all of that storage capacity, rather than just one cog in your battery bank.
Flexible Power Management:
With server rack batteries, you can maximize your charging power potential, charging multiple batteries at the same time. For example, with a high capacity power inverter, you could theoretically charge each battery individually, cutting down your recharge time significantly.
Various Voltage Options:
Server rack batteries come in various voltages (12V, 24V, and 48V), all within the same type of casing. Since you can mix-and-match, this allows you to select the best voltage for your specific power needs without having to overhaul your entire battery setup.
More Manageable Weight:
Server rack batteries usually weigh around 100 pounds each, which means they’re far from lightweights, but 100 pounds is still much easier to move around than a wall-mount battery, which could easily weigh as much as 300 pounds.
The cabinets, especially those with built-in wheels, also make repositioning and installing these batteries much less of a hassle.
Tidy Wiring and Storage:
If you have a cabinet, you’ll appreciate the clean, organized look it brings to your setup, hiding the mess of wires and keeping everything neatly consolidated. This is especially useful if you like a tidy, well-managed setup, or you’re going to be putting your battery bank in a place you’re going to be seeing it often.
Cons of Server Rack Batteries
While server rack batteries have plenty to offer, every type of solar component is going to have its drawbacks. For these stackable batteries, these are some of the main issues:
Additional Costs for the Cabinets:
Without a cabinet, server rack batteries can be a really sloppy handful. They’re heavy, bulky, and the wires are just a mess unless they’re organized properly. This means you’ll likely need to pick up a cabinet, which can add to your upfront costs—usually around $550. While it’s not mandatory, without one, you’ll have to manage the extra wiring and clutter on your own. Trust us, server rack batteries that aren’t racked are a pain.
Greater Space Requirements:
Multiple server rack batteries have a larger footprint compared to wall mounts, even when they’re in a cabinet. This means they take up more floor space, which isn’t always going to be an option if you’re someone who is working with limited space, like a cramped basement.
The More Complex Installation Process:
Hooking up multi-battery server rack setups can be daunting. With all the protocols, cabling, and communication settings needed to make sure the batteries interact correctly with each other and the rest of your system, it’s not exactly a beginner-friendly process.
Wall-Mount Batteries: Space-Saving Powerhouses
Now that we’ve covered server rack batteries, let’s take a look at what wall-mount batteries are and what they have to offer.
As the name implies, wall-mount batteries are high-capacity batteries that are designed to be mounted on a wall, helping to save floor space and provide a streamlined option for power storage. They tend to store far more power than an individual server rack battery, but the exact storage capacity will vary from one unit to the next.
As mentioned, the wall-mount battery we’re looking at is the EG4 PowerPro, which packs a serious punch thanks to its 14kWh storage capacity. While most wall-mount batteries have a fairly similar design, they tend to vary in design from one another more than server rack batteries.
So, while the EG4 PowerPro unit we’re looking at has some pretty standard pros and cons that could be applied to most wall-mount batteries, it’s important to remember that some units are going to be bigger or smaller than the PowerPro.
Pros of Wall-Mount Batteries
The following tend to be the main advantages of going with a wall-mount battery over other types:
Compact and Space-Efficient Design:
Wall mounts are perfect for setups where space is limited. Mounting on the wall gives you back that valuable floor space, making it ideal for garages, small basements, or even outdoor spaces. Even with the fairly large EG4 PowerPro, you’re getting a powerful, relatively compact unit that isn’t going to dominate your space.
Streamlined and Simplified Design:
Generally, wall-mount batteries have a more integrated, cleaner look and design that will have fewer external components. There’s no need to purchase a cabinet, and with a unit like the EG4 PowerPro, you get a sleek, all-in-one solution that’s easy to understand and set up.
Where multi-battery server racks can be difficult to set up, wall-mount units are practically plug-and-play by comparison.
Cost Efficiency:
Interestingly, wall-mount batteries often cost about the same as a server rack setup with an equivalent storage capacity. You’re not necessarily paying more for the added convenience of the wall-mounted design. Plus, you save about 550 bucks by not needing to go out and order a cabinet.
Weather-Proof Options:
Some wall-mount batteries, including the EG4 PowerPro, are available with all-weather ratings, which makes them practical for both indoor and outdoor setups. Again, for those with limited indoor space, this added versatility can be really useful.
Cons of Wall-Mount Batteries
Like server rack batteries, wall-mount solar batteries have a lot going for them, but they’re not perfect:
They Can Be Heavy and Difficult to Install:
This is a big one: wall-mount batteries are heavy, like extremely heavy. For example, the EG4 PowerPro clocks in at just over 300 pounds, making it practically immovable without assistance. Installing it on a wall or moving it down a set of stairs into a basement can be a really daunting task.
Plus, if you move, or just need to reposition your battery bank for whatever reason, it’s going to be a way bigger hassle than just wheeling a server cabinet, or carrying those server rack batteries one at a time.
Additional Need for a Conduit Box:
For a cleaner setup, most people will want to invest in a conduit box, as it helps manage the wires for your wall-mount battery. In most cases, the conduit box you’ll need will cost around $100 per battery. While it’s optional, it makes for a more organized look and is often necessary to keep things tidy, so most people end up picking one up. While it’s cheaper than a specialized server rack cabinet, it’s still another additional expense that is worth mentioning.
They Aren’t Stackable:
Due to the design, wall mount batteries are rarely stackable, especially if you have to add a conduit box. If you need more than one unit, this almost always means you’ll have to mount them side-by-side, which can take up way more wall space than you may expect.
Greater Risk of Full System Failure:
Unlike server rack batteries, where one failing battery doesn’t have to affect the others, a single wall-mount battery failure can take down your entire solar power setup. If you’re depending on just one high-capacity wall-mount battery for all of your storage, a failure means complete downtime for the entire system.
Basically, server rack batteries allow you to spread risk across numerous batteries that can work independently of each other, while losing a larger wall-mount battery can be disastrous, as most people will only use one or two for their entire battery system.
So, Which Battery Type is Right for You?
Here’s the short version:
Server rack batteries are ideal for large, flexible systems where floor space is not a problem. If you’re looking to build a scalable system where you can add batteries over time, a server rack setup is the way to go. It’s a practical solution if you’re powering an entire off-grid home, especially if you have plenty of floor space available for a cabinet or two in your basement or garage.
On the other hand, wall-mount batteries are usually better suited for tight spaces or situations where floor space is limited. For smaller projects, like the greenhouse project we’re currently working on, the wall-mount design of these batteries is far more practical. So, if you need a compact battery setup for either indoor or outdoor use, you’re going to want to go with a wall-mount battery.
Our Final Words
If you’re still on the fence, or you don’t know what you need, we recommend reaching out to a reputable retailer, like Shop Solar or Signature Solar. They’ll be able to explain the options they carry and provide insights into what would be the best solution for your specific needs.
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