Portable Weatherproof Power Station

I built this Weatherproof, portable Power Station 2 years ago to power my devices outdoors and indoors and to see if I can build one cheaper than what's on the market, and today I'm going to show you how I built this.

I waited 2 years before posting this video, so I could be sure that what I'm about to show you is safe and reliable! ...no, that's not really what happened. I just had so many projects going on, and this was quite tedious to design, build, and edit, that it kind of hit the back burner. But nonetheless, the fringe benefit is that IT IS safe and reliable having been a companion both here at home or when we're far away from home! Just read the rest of this Instructable, because it is PACKED with information!

NOTE: I'll be embedding a video version of this Instructable, but in case you're reading this and there's no video, I probably haven't published it yet. I'll update this on March 19 when the video is scheduled to be out.

A generator is great thing. It gives you power in places where there isn't any such as at a campsite, or a flying field, or as a backup in case the power goes out. Gas and diesel generators have been around since forever, but they are bulky, noisy, and usually limited in what outputs it can provide. In recent years, there's been a growth in portable power stations that use either a lithium-ion or lithium iron phosphate battery so there's now a lot of choices out there.

As for me, I built this portable generator 2 years ago and it's not only provided us with backup power for work, as a mobile charging station when I'm out flying my drones in the forest or field, and generally used here in the house to lower our electricity bill. It's got a 500W continuous/1000W peak inverter, so I can power all 3 laptops at once, a refrigerator, and even a washing machine. It also has Type C PD.30 and Quick Charge 3.0 ports. And the best thing here is the 19.5V 10A max XT60 ports, so I can power my balance charger or most any DC device that can handle that voltage, and I've also built customer adapters so I can also power my laptop directly with DC power. Normally, a laptop charger converts AC power to DC, but to get AC power I would need to convert my battery DC power to AC first, which is not really that efficient. Well I don't have to do that anymore because I can just step down my DC power to the required voltage.

I am putting in both Amazon links and Shopee/Lazada links as those are the ones geographically available to me. Just choose which one's better for you.

TOOLS

Hole Saw Kit Amazon | Shopee | Lazada

Soldering Iron Amazon | Shopee | Lazada

MC4 crimping tool Amazon | Shopee | Lazada

PARTS

Plastic Ammo Box Amazon | Shopee | Lazada

MPT-7210A Charge Controller Amazon | Shopee | Lazada

SeaMetal PD 45W Car Charger Amazon | Shopee

SeaMetal PD 90W Car Charger (Untested) Amazon | Shopee | Lazada

YouLiang 4in1 45W Dual QC3.0/Cig Lighter/Voltmeter/Switch Amazon | Shopee | Lazada

Peyto 1000W Inverter Shopee | Lazada

Waterproof power socket Amazon | Lazada

300W 20A buck converter Amazon | Shopee | Lazada

24V to 12V 5A converter Amazon | Shopee | Lazada

2 input 6 output Quick Connect Terminal Amazon | Shopee | Lazada

KCD3 Rocker Switch Amazon | Shopee | Lazada

XT30 Connector Amazon | Shopee | Lazada

XT60 Connector Amazon | Shopee | Lazada

XT60 Connector Panel Mount Amazon | Shopee | Lazada

Set of Spade of Connectors Amazon | Shopee | Lazada (you can use the MC4 crimping tool with these)

Spade connectors and sleeve Amazon | Shopee | Lazada (you can use the MC4 crimping tool with these)

MC4 Extension cable (30ft/10m) Amazon | Shopee | Lazada

MC4 splitter Amazon | Shopee | Lazada

100-120W Solar Panel Amazon | Shopee | Lazada

Extra XT60 Covers Amazon | Shopee | Lazada

CHARGER

No solar panel or no sun but you get it charged? You can repurpose an old laptop power brick

https://www.instructables.com/Laptop-Power-Brick-Adaptor-for-Your-LiPo-Balance-C/

3D PRINTED PARTS

Ammo Can Section Separator

XT60 Covers

So why did I choose to build instead of buy? Here are my 3 reasons:

1. Consumer portable generators by Bluetti, EcoFlow, Jackery, and others are expensive
2. The EcoFlow River is $179 but only has a 300W output and 245wh battery, while the River 3 Max has a 572wh battery and a 600W output which but will set you back $418
3. The Bluetti AC2A is also around $180 and also has a 300W output and a 204wh battery, while on the higher end they do have one with 1000W output and a 768wh battery but costs about $500
4. For less than price of those lower end models you can almost 2x the battery capacity and more output capabilties, and for about $220 you have more than 800wh battery capacity.
5. The outputs are limiting
6. You get your standard AC plug, a cigarette lighter plug, a couple of USB Type A, and maybe 1 or 2 Type C ports. If you need something else, you can't customize it
7. Other DIY generators for sale are just ugly!

Obviously there are also cons when going the DIY route.

1. First one obviously is you'll need a bit of elbow grease, a bit of electric know-how to make sure everything will work together, and patience in choosing your parts.
2. If building a bare-bones portable power station isn't already technical enough, the fancy interfaces and mobile apps that are usually available to consumer power stations is out of the question. Although not impossible, it does raise the complexity. By a lot!
3. Lastly, at least for the EcoFlow inverters, their X-boost actually lets you get away with a smaller rated inverter by intelligently downgrading the voltage output. What this means is your running your device at a lower voltage, so instead of 220V, maybe just 200V. Which is kind of gimmicky, because that 600W device, isn't really running at 600W anymore. But nonetheless, it will let you get away with running it in the first place, where a normal inverter's overload protection would have already tripped.

Now let's talk about our design considerations and why a lot of advice on building DIY power stations is really bad.

You can categorize a solar system into 3 main subsystems:

1. Energy collection, which is either your solar panels, wind turbines, or even an AC power supply if needed
2. Energy storage, which is your batteries and your charge controller
3. And energy output, which is our AC inverter, USB ports, and other uses of the energy that we stored

Most of the time, people give advice on what they think is "right". For example, if I said I wanted to power my refrigerator all day and night, they might give advice on how much solar panel I needed, when really the answer is about energy storage. All those solar panels will do shit when it's night or rainy. Energy collection only determines how slow or fast you can charge a battery, but ultimately it's the capacity of the battery that will determine what you can power and how long. Or if I said "I had a 500ah battery, what inverter do I need?" Someone would have a ready answer for that, but the answer may be inaccurate, because the question shouldn't be "what inverter do I need", but "what do you need to power and for how long"? Because I could just be powering a water kettle or a microwave, which would need a powerful inverter, but I won't be using it continuously so it's not drawing that much from my energy storage. Or maybe I need to power that ref earlier, which needs a smaller inverter, but it would be drawing power for far longer so you'll need to have plenty of battery capacity. In my area where power outages happen occasionally, I might want just a system purely as backup to power 3 laptops for 8 hrs, but I could afford to have it charge over a couple of days so I could just have a single 200W solar panel to save on cost. In summary, these 3 subsystems are interconnected, but they are 3 distinct variables that you will need to adjust individually based on your needs.

With that said, here are my design considerations:

My target applications are USB Type-C PD3.0, QC3.0, 19.5V so I can power a laptop directly, which can also power my balance charger for my drones. I'll just be needing a modest inverter that can provide 500W continuous and 1000W peak so I can just choose based on what can fit inside my desired case. So this inverter could power everything from a refrigerator, a portable freezer, laptops, 3D printer, etc., even a small washing machine, but heating appliances which draw a lot of power like a water kettle or microwave are out.

I want to have a 24V system, because for the same amount of watts you can deliver it with less amps therefore less heat and smaller wires. Electronically speaking, reducing voltage from 24V to something lower is better than having to boost a 12V system to a higher voltage because of better efficiency and flexibility.

As for the battery capacity, I obviously wanted to maximize what I could fit, which came out to a 7S13P battery that provided 842wh. Initially I could only source out enough 2500mah cells to build a 7S7P battery, but even this was still a very respectable 453wh, and could last me several hours charging a single laptop, gadgets, and LiPo batteries.

The first thing we need to take a look at is the box or the case that we are going to be using for our power station and I've already mentioned that I don't think using a toolbox really is a good choice aesthetically. A lot of toolboxes do not look good, the plastic is a lot of times not really great, and the lock and the hinges aren't always built for tough, so this is why I'm going with this ammo box or ammo can. There're two sizes; this one I got is the bigger one available on Lazada. It's also available on Shopee and on Amazon, and on Amazon you can even get something that's bigger and it has this tool tray up on top. But locally this is what was available to me and medium is a pretty good size. You can see the dimensions here, the medium one has a 300mm length by 165mm width and 175 mm depth inside, but it's slightly smaller than that in reality. But that is a good approximation of the size that we are going to be getting and as mentioned the plastic on this is really, really durable it's really tough; I had a hard time cutting through it and drilling through it for the holes. The hinge is really, really tough as well. It's made of polypropolene plastic. The hinge here is really made for tough so you can really fill this with all of your components and it's not going to be a problem.

So the MPT-7210A comes in this uh unlabeled box and it also comes with a manual. Thankfully it seems to be written in English. It's in an aluminum housing so it probably also doubles as a heat sink. It's thicker than expected. I just saw the picture online but I wasn't expecting it to be thick like this. So I've hooked it up to our power supply and we're going to give it 18V, ramping up from zero. It turns on around 8.5V.

For the output I'm going to be using these Universal car charger panel outputs, and the nice thing about this first of all is they're aesthetically pleasing so so and it has a uniform look so that's going to be really good at least on the aesthetic side. They also have these waterproof covers which are great because even if it rains I want it to have some sort of protection. It's not going to be totally waterproof but it's going to prevent rain from getting into those ports. This one is a PD 45W charger and this is for Quick Charge 3.0 and we also have this cigarette lighter for different applications as well as this main switch and this voltage meter so this takes an input of 12 or 24 volts but what I found is that it can take anywhere between those two voltages and tested it up to 30V without any issue. So once that's powered up it's going to light up like that and I chose the color blue because I think it's really nice but this is available in green and red as well if you prefer those colors.

They also have this universal screwing lock mechanism so as long as they have the same form factor you could switch them out. I think you can even design one in 3D and 3D print that but probably won't be as waterproof, you'll probably need to design a cover like this as well.

This is the inverter that we're going to be using this is the Peyto inverter and this is 24 volts with a 220 volt outlet and supplies up to 1,000 watts of AC power. But take note, that 1,000 watts the peak, and the continuous is 500 watts which is actually plenty for what I need to use it for. So you have to bear in mind what kind of appliances you want to connect to your inverter. 500 watts gives me plenty for fans, for charging laptops, or even powering up the 3D printer. This thing has a fan and two input lugs where you would hook up your 24 volt in. It has a power switch, and power and fault LEDs and one AC output, and an indicator LED I'm just probably going to remove this physical outlet and have something installed on the external side or on the outside of our power generator.

This is the container we're going to be using for our solar generator and the width is around 7 1/2 widths of each 18650 so our series is going to be. It's going to run seven in series over its width, and it can accommodate around 14 or 15 18650s across the whole length of this container.

You can see in the image the battery after it was fully built, it's a 7S13P battery so it has 91 18650s that are 2500mah each, for a total of 842wh. I was only able to fit up to 13P because I also had to leave some space for the BMS and Active Balancer at the end.

We are going to need to fully disassemble our DC output panel so that we can mount it properly on our ammo box. The spade connectors are a bit tough to get out, but they do come off with enough force, and then you just need to unscrew them all out of the panel.

Next up we will be cutting our box so we can mount our DC output panel as well as our AC socket, and we'll also be cutting out this space for our PD and XT60 outlets.

To make sure these all align later, I'm going to drill the screw holes and screw the front panel to the case before marking the individual holes and drilling them with a hole saw

For our AC outlet, we also need to mark where our hole needs to be, grab the right size and hole saw and cut our hole.

We're also gonna be cleaning out the burrs using a grinding stone, or you can use a manual file too.

Using a dremel or drill with a cutting disc, I also cut a rectangular hole for the switch

While we're cutting things, let's also cut some holes for our XT60 connectors, both output as well as an XT60 input

I mentioned earlier that I wanted to remove the socket because we were gonna use an external socket, but I decided there's an easier and less destructive way of doing this, which is to just solder on some wires to the existing socket. As you can see here, there are just two wires, and we're just going to pass them through the already-existing holes and solder them to the terminals. And the other end of the wire we just need to insert into our external socket and screw them down. Finally, we can screw our socket to our case.

On our inverter there is a switch which turns the unit on and off. What the switch does it basically just connects the two wires connected to it together and thereby activating the unit. So what we're going to do is we are going to take another switch. Again, a switch just basically connects two terminals with each other. So we're we are going to be connecting this switch in between one wire and the terminal on the original switch. We're just adding another switch in between in series so you'll need to have both switches on. So the original switch can be like our master switch inside, and leave that on, and then if we turn on the other switch from the outside then it's going to turn on the whole inverter.

So this is one wire from the new switch and we are just going to solder it to the original switch from where I've already removed the original wire, and the other wire of our new switch we are going to solder onto the original wire that was connected connected to the original switch. I recommend using heat shrink tubes over the two wires we joined, but if you don't have any, electric tape will do. What's important is that we wrap these bare connections in some insulation so that it doesn't uh cause any potential short circuits. For a heat shrink tube, by heating it up it shrinks the tube, hence why it's called a heat shrink tube.

This is a 300 W step down converter which can take anywhere from 6 volts to 40 volts input and you can adjust the output from 1.2 volts all the way up to 36 volts. And this can put out up to 20 amps.

I've set my step down converter to output 19.5V so I can power my FPV balance charger which takes a wide voltage input up to 30V, and 19.5V is also the voltage of most laptop power supplies so I can create custom charging cables. You can customize this based on your needs, let's say if you don't need an XT60 but you need some general purpose 12V banana plugs. (need video of velcro mount) And for mounting, I just used some velcro so I can mount it to the side. That way I can also remove it easily for maintenance.

I also got this set of spade connectors as well as these right angled ones, and this is going to be useful in case you need to add more connectors to the existing wire harness that we have. And that's what I what I'm going to do. And if you also want to completely replace the wires, maybe change up uh to a thicker gauge wire then this is going to be very

useful.

If you don't have a crimping tool, you can also use some long-nose pliers.

Since our DC panel is powered on via a switch, for every device we intend to be powered on with that switch, we need to daisy chain some wires and spade connectors to the last spade connector in the wiring harness. In my case, I'll be needing a pair of spade connectors for my PD charger. As for my XT60 outputs, I'll be connecting that directly to my battery.

The cigarette lighter that came with our DC output panel doesn't regulate its voltage because I guess they assume you'd only be connecting it to an already-regulated 12V or 24V power source, which is not good as most of the devices you can buy expect 12V and our 7S battery can put out anywhere from 21V to 29.4V. Which is why we need this 12V step down regulator. This can put out 12V 5A, but you can also source something that puts out 10A.

What we need to do is take the input wires from our 12V regulator, slide them through the spade connector cover, and we can just solder it on to the spade connector. On the output side, we are going to crimp new spade connectors. I removed both the cigarette lighter as well as the volt meter above it so we have ample space to work around, and now that we're done with our additional wiring we can now plug the outputs of the regulator to the cigarette lighter and screw it back. And afterwards, screw in our volt meter as well and plug the spade connectors in.

Lastly, I'm gonna cut a piece of velcro so I can mount the 12V regulator to the side.

Finally, let's start putting things inside our case, starting with our battery. So I just wanted to show you this quickly. I showed you this while ago but it wasn't fully assembled. And I ran out of heat shrink so this is the only section that's been heat shrunk, or rather just taped. This thing has a backing just to make the bottom a little bit more secure so it's one solid piece and there's less risk of things tearing out. It's also been secured with a lot of kapton tape. Our BMS is over here as well as our active balancer to keep all the parallel cells happy. You'll notice I have an XT30 plug here which is what I use for charging the battery and an XT60 plug which is the output. But they're both connected to the battery terminals, to the ends of the batteries. And my thinking is that I don't really need that much current when I'm charging the battery but I need a little bit more when I'm drawing from the battery.

Because of all our output devices mounted up front, I need to insert the battery sideways, making sure that my XT30 and XT60 plugs don't get caught under the battery. We obviously don't want any metal to be touching our battery for safety, so I designed this battery separator that we can place on top of the battery as sort of an insulator. This is also what I used as the backing under the battery. With this on top of the battery, I can safely place my inverter, which is housed in a metal case, above it. I initially made this 2mm thick, but scaled it down in the slicer to 1mm to print faster and it works just as well. These are printed as halves, so you're gonna need 2 of them.

Now that we have them printed, we just place each half on top of the battery. I put holes in the design not just for ventilation or to save on material, but also so I can pass my XT30 and XT60 plugs through them as well.

Here I have one of my quick connect terminal connected to an XT60 connector which plugs into our battery, and we plug in the wires of our DC output panel as well as our XT60 outputs. Not sure if you noticed it, but our DC output panel has an inline fuse for added safety. The wire for our inverter also has an inline fuse, but uses a blade fuse instead of a glass fuse. Our 1000W inverter fits right in behind our DC output devices and it is a snug fit. So we screw down the positive wire to the inverter, and then snap it locked to the quick connect terminal, and then we just do the same for the ground wire.

Finally we get our MPPT Charge Controller and place it on top of our inverter, and connect the battery wire to the XT30 plug of our battery. Most solar panels have an MC4 connector, so I made my own MC4 to XT60 adapter, and my XT60 input port is connected to the input port of the MPPT, and the MPPT in turn charges my battery. All that's left is to tidy up our wires a little bit and we're done!

NOTE: Video will be published 19 March, 10PM GMT+8

Well, there you have it, that's how I built my portable power station 2 years ago, and hopefully you'll also get to build your own with the help of this video. Some of the clips in this video go all the way back, while some are relatively recent, because a lot has changed in those 2 years. I've had to swap out some parts, and at one point I had literally every output going through this switch and I eventually learned the hard way why that wasn't such a great idea. So while the finished build seemed quite straightforward, building this thing as well as making this video, was hardly a straight path.

There are also definitely some things I would like to improve on in the future.

1. While this is a very functional and purpose-built power station, something that looks like it could be used by the military, I would like to have some high-tech 21st century polish by way of some nice fancy displays. Right now, I only have a voltage display outside and I have to turn on the output panel, or if I wanted to know information about charging, I'd have to open it and take a peek inside at the MPPT. Maybe I can put an Arduino or ESP32 to get some readings or log data that I can check through a phone app.
2. Speaking of opening, a tradeoff I had to make when I decided to maintain the waterproofing of this case is the limited ventilation. When charging and when the inverter is putting out its maximum wattage, it gets really hot inside and while the individual components have cooling, I have to leave the case open for the hot air to escape.

The best part is a lot of this is upgradable! I actually have a better PD charger that can put out 45W per channel on the way, and I will link to it as well, but as I've not tried it myself, try it at your own risk.

Other than that, both the battery capacity and the output capabilities of this thing are a winner and you just can't beat that price! Well I hope this video has been useful, educational, or entertaining, do bookmark or add this to one of your playlists, make sure you're subscribed and click on that bell and the like button as well so more people get to see this video. And I am going to leave you with that, as always keep building and keep flying! Cheers!