Going solar doesn’t have to mean spending tens of thousands of dollars on high-end batteries, especially if you’re just building a basic off grid system, a mostly DIY setup, or installing a battery bank somewhere that doesn’t require UL-listed equipment.
That’s where budget options like the WattCycle Server Rack Battery are supposed to come into play. On paper, it costs roughly half as much as something like an EG4 LL 48V Battery, but the big questions are always the same: is it actually worth buying, as well as reliable enough to be practical?
In the past, we’ve tested a lot of budget server rack batteries, including options like a Vatrer Power Solar Battery, an Eco Worthy Battery, and the RUiXU 48V Battery. Honestly, when it comes to budget-friendly server rack batteries, we’ve been disappointed more often than not. So, we picked up the WattCycle 48V 100Ah Server Rack Battery expecting to be disappointed, but still hoping to find a cheap option we could feel comfortable recommending.
Let’s find out if it actually gets our stamp of approval, or if you should just spend more on something from a more reputable battery brand.
Before we get into testing, here’s a quick technical overview of what you’re supposed to be getting with this WattCycle battery:
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While we have noticed that the price has bounced around a little bit since we reviewed it, there’s no getting around the fact that anywhere below $700 is ridiculously cheap for a 5.12kWh server rack battery. That’s literally half the price of a similar battery from a more well-known solar battery brand, like EG4 or Rich Solar.
With that said, a cheap battery is pretty much useless if it doesn’t do what it’s supposed to do. So, we decided to put it through all of our usual performance tests. Here’s how this Watt Cycle battery performed:
One of the biggest surprises with the WattCycle battery was how well it actually performed across almost every single one of our real-world tests. It accepted the full 100A charge rate without any issues, meaning you could theoretically charge it from empty to full in about an hour with the right power inverter and charging source.
On the discharge side, things got even more interesting. While it’s rated for 100A continuous output, we were able to surge over 200A, pushing more than 11,000W to start a compressor while already running a significant load.
That’s impressive performance for any solar battery, especially one of the most budget-friendly batteries we’ve ever tested. Most batteries heavily limit surge output, so it’s nice knowing that you'd be able to start some fairly demanding loads if you were running several of these batteries in parallel.
When we tested the efficiency, it was effectively 100% efficient, which is exactly what you want to see from any type of solar battery. If a LiFePO4 battery isn’t efficient, something is very wrong, so it’s good to see the basics done right here.
Given the recent ice storms, we’ve been really mindful of cold-weather performance when reviewing batteries, portable power stations, and other pieces of backup power equipment.
With this in mind, we put the WattCycle battery in a freezer for 24 hours and brought it down to a temperature of -25°C (-13°F). As expected, it refused to accept a charge at that temperature, which means the Battery Management System (BMS) is working exactly as it should.
With that said, it still provided some discharge voltage (around 46V) instead of fully cutting off output. Ideally, a battery should completely shut down under those ice-cold conditions, so this was the one test where it didn’t behave perfectly. It’s far from a deal-breaker, but something to consider if you plan on using it in a particularly cold climate.
Now that we’ve covered the surprisingly positive results of our in-house testing, let’s take a look at all of the things we liked about this cheap battery:
For a truly dirt-cheap server rack battery, this thing performed way better than expected. The surge capability, charge acceptance, and the battery’s overall behavior were all solid.
If you’re shopping for a cheap server rack battery, you just want to know that it will work. The extras are usually not important, even though this battery does have some surprisingly good features beyond its basic functioning.
Speaking of the frills, the built-in display screen you get with this battery is genuinely really impressive. It’s responsive, full color, easy to read, and provides tons of useful data without needing to open the app.
This is one of the better screens we’ve used on a server rack battery, which was a huge surprise given we assumed a battery this cheap would be really bare bones.
While the screen stole the show, the app works well and lets you remotely enable or disable discharge. That’s a feature you usually see on power stations, not server rack batteries.
If you’re looking at a cheap battery setup, there’s also a good chance you’ll be hoping to pick up an affordable inverter. Having a functional app that allows you to control discharging rates can be incredibly useful with a basic inverter, as it allows you to control things in a way that is usually reserved for the more high-end inverters from brands like EG4 and Sol-Ark.
There are no dip switches or manual ID settings. Instead, the battery automatically identifies itself when paralleled with others, which makes scaling your system significantly easier.
Whether you’re planning to fill out a full server rack cabinet from the start, or you just want the option to expand and upgrade your solar power system in the future, simplified paralleling is going to be a huge plus.
A pair of bolt-on handles are included with this unit, which is something every battery should have. Unfortunately, it’s not something we received when we reviewed a similar server rack battery from EcoWorthy in the past. From our own experience, we can tell you that having handles really helps when you’re transporting a metal battery that weighs almost 100 pounds.
WattCycle also claims to be releasing stacking feet that will make safely stacking these batteries easy, even without a server rack cabinet. While they’re not out yet, this has the potential to be a big cost saver for DIY builders, especially given some of the sky-high prices we’ve seen for cabinets lately.
For a budget battery, this thing actually looks really good. We’ve tested some batteries that looked like absolute junk, but this one feels and looks like a legitimate product. Honestly, if you just looked at the battery and the display screen, you wouldn’t think this was a solar battery that had entry-level pricing.
At roughly half the cost of a similarly sized EG4 battery, the value proposition is hard to ignore. You could buy two of these for the price of one name-brand unit. If you’re at the point where you’re trying to size your battery capacity, but you’re worried about costs, having something this cheap and scalable could be really useful.
While there was a lot to like, no battery is perfect, and this Watt Cycle battery is no exception. Here are the main issues we had with the battery and the brand:
This is the biggest issue we had with this battery. WattCycle advertises UL certification right on their website, but only the cells are UL-listed. The battery itself is not UL-listed. That means it’s not going to be code-compliant for a lot of legal installations. Don’t get fooled by the marketing here.
Honestly, we just wish they were more transparent, rather than creating this confusion. It’s a bit sketchy.
Speaking of sketchy information, their entire website feels pretty sketchy. It’s loaded with AI-generated images and it’s missing documentation like manuals and detailed spec sheets.
Not only did that give us an odd feeling about placing an order, not having all of the documents and manuals publicly available means integration with third-party inverters is going to be harder, especially if you need technical support from the inverter company.
This is a good-looking product that works really well, so why release such an off-putting website? Just take legitimate photographs of your product and give buyers more confidence about placing an order.
Something weird that we picked up on is the face that the positive and negative terminals are flipped compared to most standard server rack batteries. If you’re mixing brands in a cabinet, which is something we do a lot, your cables may cross awkwardly, which is annoying and messy.
Not only are the terminals positioned in a weird way, the included parallel cables are very short. If you’re stacking batteries with spacers or inside of a cabinet, they likely won’t reach, which means extra cable purchases and more setup hassle.
As of now, you’re not getting high-level customer support from this brand. Responses are slow, and technical expertise is limited. That’s often the trade-off with budget brands. If you want reliable customer support, we’d recommend ordering from a more mainstream brand, or even a reputable retailer, like Signature Solar.
Another thing we have realized since we reviewed this battery is the fact that prices fluctuate frequently on WattCycle’s website. Not only is this frustrating for potential buyers, it makes recommending their products difficult for us, as we can’t just provide straightforward price expectations. It’s still really cheap, but price volatility is frustrating.
Luckily, we were able to contact WattCycle ourselves and ask about this issue. While they didn’t make any sort of promises, they did give us a discount code (THESOLARLAB) that will take 10% off the lowest price.
This WattCycle battery is for people who want maximum storage per dollar and don’t need UL-listed equipment.
If you’re building an off-grid cabin, a backup system in a backyard shed, or a DIY solar setup where code compliance isn’t required, this battery actually makes a lot of sense.
It’s also a solid choice if you know what you’re doing and don’t need premium customer support. For the price, you’re getting genuinely good performance, which is rare in the budget battery space.
However, if you live somewhere that requires a valid UL-listing, or you just want reliable technical support, you’re still better off spending more on something cheaper from a more reputable brand, like the EG4 LIFEPOWER4 Server Rack Battery.
We’ve tested a lot of budget batteries, and the WattCycle is one of the first cheap server rack batteries we actually feel comfortable recommending. It’s not perfect, and it’s definitely not what we’d classify as a premium product, but for half the price of name-brand competition, it delivers real performance.
If you’re chasing the best bang-for-your-buck storage and don’t need UL certification, this might be one of the best budget options on the market right now.
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