DIY Power Tank (Co2 Tank) for Airing Up Tires

How To Build Your Own CO2 Tank or “Power Tank” – A Few Options To Consider When Building a DIY CO2 Tank For Airing Up Tires

Let’s be honest, Power Tanks are expensive. Extremely badass, but expensive.

I have had the privilege of test-running a 10-lb power tank for the last couple of trips. Big thanks to Tyler at MORRFlate for lending me his setup to see if CO2 was for me. My mind was blown when I saw all four 35″ tires air up in less than 60 seconds. You literally watch 15PSI reach 35PSI on four tires in real-time. Squishy turns to firm… fast.

The specific Power Tank I used was decked out with the Super Flow CO2 regulator kit (XP400 Pro Series) with the Super Coupler. This setup is seriously impressive. The build quality of the regulator alone is pure eye candy. The red on black with the Power Tank logo branded gauges might be enough for you to pull the trigger. The regulator, when connected to the tank, is far more impressive in person than pictures do it justice, and it operates flawlessly, as you would expect given the cost.

The XP400 is their top-of-the-line regulator and has some staggering numbers. It features 48 CFM (cubic feet per minute) flow rate at a maximum outlet pressure of 400 psi. Compare that to the ARB Twin we have installed with a 4.68 CFM flow rate at 29 psi with a max pressure output of 150 psi. There is literally no comparison here. This is not apples to apples, this is apples to something far more delicious.

How much are Power Tanks?

Power Tank outperforms any portable compressor on the market when it comes to speed, and if speed is what you are concerned about, then a Power Tank is absolutely for you. Performance comes with a cost though.

Power Tank kits with the tank and regulator can run anywhere from $450-$750 or more depending on the accessories you buy.

XP400 or HP250i?

The XP400 kit alone (with no tank) runs around $380 but you can find it for about $350 from other sites. If that’s a little too expensive, no worries, you can grab an entry-level regulator, the PT HP250i.

The HP250i features a 45 CFM flow rate at a maximum outlet pressure of 250 psi. This more affordable version is only $325 and you can find it other places online for $299.

I found a few of these on Craigslist for about 20% less than you will find online. If you do your research through Craigslist and Facebook marketplace, you might find a decent deal.

Power Tanks are Badass, let’s buy one!

Oh that’s right, they are super expensive and I can’t afford one. Ok, let’s build a cheap one.

Well, the cost of building an exact replica of a dual gauge adjustable regulator like a Power Tank version can actually get pretty expensive. Before going all-in with a DIY setup, let’s address some items:

Questions to ask yourself: 

• What is your desired PSI output range?
• Do you want to monitor tank pressure?
• Is fixed-rate ok, or do you need to regulate output pressure?
• Do you need a dual, single or no gauge?
• What air hose and psi gauge are you using to fill up tires?
• Do you plan on using air tools?
• Do you plan on resetting Beadlock wheels?

Power Tanks Vs. DIY Power Tank

A DIY Power Tank is going to achieve the same end-goal for most users when compared to the brand name. With that in mind though, Power Tank does have multiple options with their tank sizes and regulators, so it’s important to consider the psi you need before deciding on either direction.

Running Air Tools? 

Air tools made for general use with portable air compressors typically require 0 to 5 cubic feet per minute (CFM) at 70 to 90 pounds per square inch (psi), whereas with larger tools connected to stationary systems, the requirements usually exceed 10 CFM at 100 to 120 psi. – quincycompressor.com

Regulator & PSI?

Depending on the regulator you are running, you will see different psi output. With the Power Tank, you have a 400 psi and 250 psi regulator option. With a DIY version, you can run the fixed rate 150 psi regulator or something like this 400 psi (Power Tank replica) version. I cannot speak to the performance of this 400 psi replica version, but it has decent reviews. If you don’t want to piece together your own regulator, consider the replica version.

How much psi do you need?

For the most part, 150 psi will cover most air tools you may need on the trail along with airing up tires quickly. If you don’t “need” 250 psi and don’t want to fork over the coin for a Power Tank, then maybe look at a DIY option. It really just depends on your situation. For most off-roaders and overlanders, 150 psi is plenty. The difference between 150, 250 and 400 psi is speed and power. The higher the psi flow, the faster you can air up your tires. Finally, some air tools require a high psi which is another reason why you might want to go with a high-flow psi regulator.

DIY CO2 Tank: Tools and Materials

Let’s look at the components that make a portable CO2 tank with a decent regulator.

1. 10lb CO2 Tank
2. Primary Regulator (tank pressure)
   • Tank Gauge
3. Secondary Regulator (output pressure)
   • Output Gauge
4. ARB Coupler
   • Optional brass coupler
5. Scuba Tank Handle
6. Coiled Yellow Hose
   • Upgrade to the MORRFlate
7. ARB Tire Inflator

Note: I used a 5-lb tank from an old kegerator I had. However, I highly recommend the 10-lb tank if you are going to build one. I will explain why later. Just know that is likely the only thing I would have differently below.

CO2 Tank

For a tank, you can grab a 5-lb or 10-lb tank from Amazon, or even Craigslist. If you can jump on Craigslist, sometimes you can find a really good deal on a CO2 tank. But,  just be careful here and know what to ask when shopping. The Department of Transportation (DOT) requires that most portable CO2 tanks, both new and used, be recertified every five (5) years so always ask how old a CO2 tank is before buying one. If the tank is 5+ years old, don’t buy it or just low-ball the person and then exchange the out of date tanks for the standard fee + recertification cost at a fire extinguisher company near you.

5-lb, 10-lb or 20-lb tank?

If the budget allows, you should opt for a larger tank. The smaller the tank, the more often you will need to refill it, but on the other hand, it is the most compact of the three sizes. The 10-lb tank is going to be the middle of the three and is probably the happy-medium of pressure capacity and physical size as well. A 20-lb tank is likely going to be too big for most 4Runner and mid-size off-road builds but may work on some full-size off-road/overland builds given you have space to accommodate it.

Regulator

The regulator is the most important part of your DIY CO2 tank, so what features do you want?

Let’s start with what psi you need.

As previously mentioned, you can keep it fixed at 150 psi output, or even less. For running air tools, you can also run that same 150 psi and likely be fine. If you for some reason need to adjust the psi coming from the tank into your tires or tools, then an adjustable CO2 regulator is what you want, which is what Power Tank offers.

On our DIY tank, we added a secondary regulator in order to drop our psi down from that fixed 150. If you are looking to fill air lockers with CO2, 150 psi will be too high and you will want to regulate your air down to about 80-100 psi so you don’t blow any seals. You can add a secondary fixed regulator to the 150 psi fixed regulator in order to air up your lockers. If you are going this route though, you should probably be looking at an adjustable regulator like the PT or the replica version, or of course, you can just build your own.

For our case with 35″ tires, I don’t see the need for 400 psi or even the 250 psi regulator; but if you have other needs like airing up 40″ tires really fast, then maybe larger rated psi regulator is for you.

Some air tools require really high psi as well, so if you are looking to run air tools with high psi requirements then consider a higher psi rated regulator.

Fixed-Rate 150 psi Regulator

Pictured above is the fixed-rate 150 psi regulator and a single ARB quick connect 1/4″ air coupler. This is the most basic DIY regulator you can run. You can connect an air hose straight to this regulator/coupler and start airing up your tires.

The fixed-rate (no valve to regulate the pressure) 150 psi regulator will provide a “fixed-rate” of 150 psi into our tires.

There is nothing technically wrong with this setup at all. It’s quick, easy and just works.

We went a step further with ours though.

Second Regulator (Output Pressure)

Your secondary regulator is going to control the pressure coming out of your first regulator. If your first regulator is a static 150 psi, then your second regulator can drop that psi down further.

If you need to air your lockers or anything else that requires a lower psi, then this regulator will control that. From here, we can adjust our psi down to 80 psi or even lower depending on our needs. For this part, you can go with an affordable option like the Bostitch (1/4″ inline regulator with 1/8″ gauge fitting) or step it up and go with an upgraded option when you buy a 1/4″ regulator and 1/8″ gauge independently of each other.

Originally, I purchased the Bostitch and even though it works, I wasn’t thrilled with the performance. The adjustment dial started sticking after a few times of use. After quite a bit of digging online, I found the SPEEDAIRE air regulator and it has worked great.

Gauges

Adjustable, dual gauge, single gauge or no gauge?

You don’t “need” a gauge on your regulator to air up your tires, but they might help, depending on your situation. At the end of the day, all you really need to air up your tires is the one main regulator and a coupler. That’s it.

Top Gauge: Tank Pressure

If you want to read the pressure inside your tank, then you would want to add a psi gauge that is rated for that tank. For example, a 5-lb or 10-lb CO2 tank when full will read 600-1000+ psi depending on the temperature so you use will a gauge that is 800 psi or over in order to read that tank. In our case, we are running a 0-2000 psi gauge.

But, just because your tank reads 600-1000+ psi doesn’t mean you have a full tank. CO2 is mostly a liquid state inside the tank and a small portion of gas at the top. The 600-1000 psi should stay constant throughout uses.  Psi will drop or rise depending on temperature. If the tank is nearing empty, then the psi will drop drastically but only once the tank has reached mostly gas, not liquid.

You really don’t need this gauge, though. You can feel when the tank starts to get empty just by lifting it up.

Bottom Gauge: Output Pressure

With a fixed regulator like the Gentec 227C-150, you have a set psi (150) that is coming out of the tank. That means you can’t lower or increase the pressure unless you add a secondary regulator.

Our bottom gauge is connected to the SPEEDAIRE air regulator. This is a 0-160 psi gauge that will read the output pressure of the tank and we control that with the SPEEDAIRE regulator adjustment knob.

With the SPEEDAIRE air regulator, we can control the exact psi coming out of the tank.

Coupler

There are lots of couplers out there.

From the ARB quick connect we used to basic brass 1/4″ couplers on Amazon or Home Depot, you can find affordable options out there. You may even have one laying around your garage. There are high-end brass fittings and then zinc-plated steel fittings for cheaper.

Some of the universal zinc-plated steel kits from China can have warped threads while the single brass fittings tend to be higher quality, but not always. Some pre-packed kits can be nice. It really just depends on the brand.

We had a left-over ARB coupler from the ARB twin compressor we are running so that’s what I used.

Handle

We went with a pretty cheap version for a handle. You can find the “Power Tank” style handles on eBay or Amazon but even the off-brand versions are expensive, sitting around $40+.

Whatever you are looking for when it comes to a handle, just make sure the inside diameter of the handle matches the outside diameter of your tank. There are lots of scuba tank handles out there but not all of them match regular co2 tanks out there.

We had to modify our handle with a file in order for it to fit the circumference of the co2 tank. We took about 1/8″ off around the entire inner diameter.

SAFTEY DISCLAIMER: This handle is not an added level of protection. Pease do not travel with this regulator attached to the tank while driving. The handle on this tank does nothing in the way of protecting your regulator. Power Tank on the other hand offers an extremly strong handle designed to protect the regulator and the main valve. You can find the Power Tank handle here, or the cheaper DIY version here. There is no gauruntee that the DIY version is going to be as strong as the branded version. Use yoru best judgement. Trail4R.com is not responsible for transportation methods of DIY tanks.

Coiled Air Hose

For the most part, we are going to run our setup through a MORRFlate but there are many options.

If you do not have a 2- or 4-way tire inflation/deflation kit or don’t want to spend the money on one, there are plenty of single options out there. You can find many 150 psi rated straight or coiled air hose lines for around $20-$50.

For coiled lines, you can go with a cheap option from Interstate Pneumatics or an upgraded option from Flexzilla, like their Air Recoil Hose.

For flat lines, you want to look at Flexzilla Pro Air Hose, they make some of the best non-binding hose options out there, but there are many other options.

Inflator

Your inflator and/or inline tire pressure gauge is incredibly important. This is one area you don’t want to skimp. Tire pressure gauges can range from $15-$50+.

Having a nice gauge is important because, typically speaking, the higher the quality gauge you have, the more accurate the reading of the psi is.

If you buy a cheap gauge, your psi readings may be off and can result in inaccurate tire pressure. You want your readings to be as accurate as possible so all four tires are running the recommended tire pressure.

Final Thoughts

After 3 months of testing the Power Tank, and the DIY tank, I learned a lot. There was a lot of trial and error while building the regulator. I was constantly testing new parts and products which resulted in blowing through CO2. This caused the need to drive 30 miles both ways to go refill the tank in order to keep testing. At the end of the day, the regulator is solid and works for how I intend on using it… airing up my 35″ tires.

Between the Power Tank and the DIY version, the Power Tank obviously wins. It’s a much higher-quality build, has a lifetime warranty, and is more capable than this DIY option.

Testing the tanks:

I tested both units using the MORRFlate on four 35″ (35×12.5R17) Tires.

• 10-lb Power Tank (150 psi): 18-35 psi in 43 seconds.
• 5-lb DIY Tank (150 psi): 18-35 psi in 56 seconds

The DIY version was fixed at 150 psi and the Power Tank was running the 400 psi regulator but set at 150 psi. I think the Power Tank was pushing a true 150 psi but the DIY tank was not technically pushing exactly 150 psi out of the tank. I was able to get two full refills from the 5-lb DIY Tank (150 psi) at 18-35 psi. I did have about 10% left in the tank but not enough for a full refill.

I will come out with another article that compares multiple tank sizes, swapping regulators, and for the sake of the blog, I will likely buy my own Power Tank. They really do make a kick-ass product. I still have a lot to cover here; storage in the 4Runner, mounting the tank, Nitrogen, testing air tools on the DIY regulator, airing up lockers, setting a bead, and more.

What should you buy? 

If you are reading this then it probably comes down to cost. I just added everything to my Amazon cart and it came out to $165.76 + $18 for the secondary SPEEDAIRE regulator. Your grand total would be around $183 for a DIY 10lb version vs. $500 for a 10lb basic package Power Tank. If you want a fixed-rate 150 psi CO2, you can get a 10lb tank set-up for around $120.