OSCAL Powermax 3600 Review – A Viable DELTA Pro Knockoff or a Pile of Junk?

Sep. 17

Here at The Solar Lab, our mission has always been to provide honest, educational content for anyone interested in solar technology. We take pride in our integrity, aiming to guide people towards the best products for their needs. But when we come across something that's just plain low-quality, we're not going to sugarcoat it.

That brings us to today’s review of the OSCAL Powermax 3600, which is openly marketed as a knockoff of the well-known EcoFlow DELTA Pro—but at a fraction of the price.

Spoiler Alert: This review doesn’t end well for the OSCAL. While we don’t take any joy in tearing down a product or the company that makes it, we also won’t pretend a product is good when it’s not. So, let’s dive into why the OSCAL Powermax 3600 falls short and decide if it's worth the supposed savings.

Our First Impressions and OSCAL’s Bold Claims

OSCAL approached us with the claim that their Powermax 3600 was a "DELTA Pro replacement" or, as we like to say, a knockoff. They were confident, treating it like it was some kind of DELTA Pro killer, but at half the price. Intrigued, we agreed to give it a shot.

OSCAL’s slogan may be “Only the Brave”, but is it more of a case of “Only the Delusional” when they thought they could just send us a copycat knockoff version of a popular product and expect us to be blown away? Well, from the start, it certainly felt that way…

When the unit arrived, it wasn’t even the power station at first—it was just the expansion battery. After a bit of back-and-forth, we finally got the full power station delivered. But right out of the box, things went downhill. One of the wheels was broken, and the unit itself felt really far from anything you could describe as solid. Still, we decided to push forward. After all, most of these immediate issues were cosmetic, and looks aren’t everything—it’s performance that really counts.

Breakdown of the Specs (Including the Fine Print):

Let’s talk about the numbers first because that’s where OSCAL really started to lose us.

Here’s what OSCAL advertises (with a few asterisks we’ll explain in more detail later):

Battery Capacity: 3,600Wh* (but 3,000Wh for U.S. customers)
Inverter Capacity: 3,600W* (again, lower for U.S. and Japanese customers)
Surge Rating: 7,500W Surge* (something we couldn’t verify)
AC Input: 1,800W
Solar Input: 1,600W
Output Ports: 3 x 120V outlets, 1 x 30A plug, 1 x 12V car plug, 1 x Anderson port, 2 x USB-C ports, and 3 x fast-charge USB ports

On paper, those specs aren’t bad. The ability to charge from a standard wall outlet in just a couple of hours is impressive, and a 1,600W solar input is nothing to sneeze at. But, as you’ll see, the problem isn’t with the advertised specs—it’s how it actually performs and just how misleading those specs can be.

For example, the specs and even the thing’s name suggest that the OSCAL Powermax 3600 boasts a 3,600Wh lithium iron phosphate battery, but, and this is a big but, that number only applies to the European model. In the U.S., it actually just comes with a 3,000Wh battery—something they conveniently hide deep in the fine print.

These specs are just all over the place. Sure, plenty of brands exaggerate what their products can do. Whether that’s because they test them under ideal factory conditions that don’t come close to replicating real-life scenarios, or because they’re just being a bit generous with the numbers, it’s something we see often. However, OSCAL takes this over-exaggeration stuff to a whole new level.

Hands-On Testing: What We REALLY Didn’t Like

Before we get into any of our performance tests, let’s talk about this thing’s build quality. The broken wheel was a red flag right from the start. Then, there’s the insane noise—this thing hums like an insect zapper. It’s the only power station we’ve tested that emits a high-pitched whine just from being powered on. Trust us, it’s bad; even the mice in your garage would probably move out. It also just looks and feels pretty cheap.

But hey, maybe it still performs, right? Nope, this is where it truly falls apart.

Testing the Performance (or Lack of Performance):

Our first test was to check output power. We planned to run a 3,600W load since that’s what they claim the product can handle. Except… surprise! It’s only a 3,000W inverter for the U.S. version. Trying to run anything higher resulted in immediate shutdowns.

Like we pointed out in the specs breakdown, they’re sneaky with the asterisks. The unit’s specs vary depending on where you buy it. Basically, OSCAL’s marketing misled us, and that’s a major strike against them.

Next up, we tested battery efficiency. A unit that claims to have a 3,600Wh battery should give you close to 36 hours of runtime for a 100W device. Of course, some power is lost to the inverter and other internal systems, but you still expect somewhere close to that. However, the OSCAL Powermax 3600 only managed around 70% efficiency when we tested it. This means your hypothetical 100W device would only run for 25 hours instead of close to 36.

That’s just not good enough, especially when compared to the EcoFlow DELTA Pro it’s supposed to compete with. We have tested the DELTA Pro countless times and it consistently ranks amongst the best power stations for efficiency. The OSCAL just isn’t in the same league as the original.

OSCAL vs. EcoFlow - Why the DELTA Pro is Still King

Now, let’s compare this knockoff to the product it’s trying to replace: the EcoFlow DELTA Pro. There’s no denying that the DELTA Pro is more expensive, but as it turns out, that’s for quite a few good reasons. Here’s why the extra cost is worth it:

1. Build Quality:

The DELTA Pro is a tank that has proven it can stand the test of time. It came out over three years ago and plenty of the original models are still going strong. There’s a reason it remains one of the best-selling power stations on the market.

On the other hand, the OSCAL Powermax feels like a cheap toy, especially when you actually do a hands-on comparison to the DELTA Pro. And, trust us, we don’t just feel this way because ours came with a broken wheel; every single component on the DELTA Pro feels significantly more durable than what you get with the Powermax. Unsurprisingly, more thought was put into the DELTA Pro’s design, and it is constructed from higher-quality materials.

2. Performance:

The DELTA Pro actually delivers on its promises. If EcoFlow says it has a 3,600Wh battery, it means you get a 3,600Wh battery. And efficiency? You actually get a respectable 85-90%, instead of something that performs poorly straight out of the box.

Sure, the OSCAL is cheaper, but you actually get more bang for your buck in terms of performance and runtime with the real thing.

3. Customer Support:

This is a big one. EcoFlow is a well-established company with actual, real-life customer service representatives. When you buy a DELTA Pro, you know you’re getting a product that’s backed by a team that cares about their products and brand image.

On the other hand, OSCAL is more like an AliExpress mystery box company. Once you buy something, good luck getting any help. They’re basically slapping a logo on some generic, low-quality product they ordered in bulk from a sketchy supplier.

Even OSCAL’s website is a joke. From the confusing layout to the really shoddy Photoshop images of their products, it’s just garbage. Plus, knockoff power stations are just the tip of the iceberg—they sell rip-off versions of iPads, iPhones, and a bunch of other junk.

4. Safety:

When you’re dealing with companies that repackage knockoff products, like OSCAL, you really can’t be surprised when they cut corners on safety. We ran tests, and while it worked, there were none of the built-in protections that are standard on higher-end models, like the DELTA Pro. The cooling fans didn’t kick on when they should have, and there’s no real failsafe if something goes wrong.

Again, no surprises here. In all likelihood, OSCAL does not test their products themselves. They’re just shipping you a repackaged version of what AliExpress or some other mass market retail website carries.

Our Final Thoughts: Is the Lack of Quality Worth the Savings?

At the end of the day, you get what you pay for. The OSCAL Powermax 3600 is certainly cheaper than the EcoFlow DELTA Pro, but that’s about where the benefits end. The quality control is terrible, the efficiency rating and real-life performance are poor, and the overall experience just using this thing is frustrating. From broken wheels to noisy operation, it’s clear that this knockoff isn’t in the same league as its inspiration.

Sure, you might save $1,000 upfront, but there are always hidden costs. In this case, poor performance, lack of customer support, and potential safety risks all make it a poor investment, especially in the long run. We didn’t get to use it long enough to see how it holds up, but we’d be shocked if it actually lasted anywhere near as long as a legitimate DELTA Pro, or something similar, like an Anker F3800.

It’s also worth repeating and stressing the fact that we didn’t enjoy tearing down the OSCAL Powermax 3600, but we owe it to our readers and viewers to be honest. We’re not here to bash products or brands just for the sake of it, but when a company sends us some low-quality junk and expects us to blindly promote it, we have to call it like we see it.

Bottom line: Save yourself the headache (and possibly serious safety risks). If you don’t want to waste your money, stick with a trusted brand like EcoFlow, Jackery, or Anker. You’ll be glad you did.

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