They’re marketed as “Solar Generators” or “Solar Power Stations” but what they are is a nice box with a battery, charge controller, and inverter inside. [DoItYourselfDad] on Youtube decided that since all of those parts are available separately, he could put one together himself.
The project is a nice simple job for a weekend afternoon. (He claims 2 hours.) Because it’s all COTS components, it just a matter of wiring everything together, and sticking into a box. [DoItYourselfDad] walks his viewers through this process very clearly, including installing a shunt to monitor the battery. (This is the kind of video you could send to your brother-in-law in good conscience.)
Strictly speaking, he didn’t need the shunt, since his fancy LiFePo pack from TimeUSB has one built in with Bluetooth connectivity. Having a dedicated screen is nice, though, as is the ability to charge from wall power or solar, via the two different charge controllers [DoItYourselfDad] includes. If it were our power station, we’d be sure to put in a DC-DC converter for USB-PD functionality, but his use case must be different as he has a 120 V inverter as the only output. That’s the nice thing about doing it yourself, though: you can include all the features you want, and none that you don’t.
We’re not totally sure about his claim that the clear cargo box was chosen because he was inspired by late-90s Macintosh computers, but it’s a perfectly usable case, and the build quality is probably as good as the cheapest options on TEMU.
This project is simple, but it does the job. Have you made a more sophisticated battery box, or other more-impressive project? Don’t cast shade on [DoItYourselfDad]: cast light on your work by letting us know about it!.
COTS components.
Commercial – Off – The – Shelf
Thank you. I kinda figured it was something like that, but I’ve never seen that one before.
I always heard it as Common Off The Shelf.
That is correct.
Nope, it’s always been “commercial off-the-shelf”, as in you can simply wander down to your local store an buy it.
Interesting. I stand corrected.
No fuses and/or circuit-breakers ?
Thank you or writing out the COTS thing. I looked it up before I saw the comment but still useful to see.
On the project .. Its a good idea. A downside is with the case however. Those things are great in a closet for light duty. They’re not so great after exposure to the elements and even pretty limited sun exposure. They get brittle and start breaking. Would definitely look for something in a black plastic (ime black is easy tofind and tends to have the most sun resistence) or at least opaque plastic for the job.
black plastic absorbs almost all the spectrum, so its just sitting there sucking up UV all day long, if its not pure crap it might be reinforced with a fiberglass, but its actually the worst thing to put outside
but its sleek looking and its the cheapest option, which is the only reason its popular
Black is typically used for UV resistant plastics. They add carbon black to the polymer and the UV is mostly absorbed by the carbon black instead of penetrating into the plastic and destroying the polymer chains.
UV breaks down the plastic directly. Black gets hot and breaks down anyway.
As an aside, because of the added carbon black acrylic is just a little bit harder to laser cut than other colours. White cuts beautifully for some reason.
I have the same thoughts about platic deteriorating in the sun, doubt this will last long.
I think there are UV resistant spray paints (could go with clear) which may help. I’d still expect the case to have a limited lifespan
I see that several items are wired on permanently like the gauge. There is also no circuitry to disale output if the battery gets too low, or is that in the battery itself?
It needs a big off switch I think.
That would be a function of the Charge Controller.
“fantastic machine… the M5… no off switch !” /Dr. Leonard McCoy
Yes, the BMS (Battery Management System) inside the battery has many protections (over and under charge, both per cell and global, over and under current, over and under temperature) but it’s a good idea to use fuses.
Fun fact: most of these BMSs with bluetooth connectivity have no protection (the password in the app is just smoke and mirrors) so anybody in the vicinity can change the parameters and possibly destroy the battery.
Luckily you can find repositories on github to use an esp32 to monitor the battery, integrate it in home assistant and keep the channel busy (so nobody else can connect).
That battery almost certainly has a BMS which would shut off power before letting the voltage get low enough to damage the cells. If he were using a more modern inverter, it would probably have a screen and logic for a cutoff voltage.
The lighting is so shitty it looks like its ai-generated. Also, isn’t this how every ‘solar battery charger’ setup is made, minus the overpriced pelican cases?
I just finnished a wheeled hand cart version of this, 85 watt panel, with two large 12 volt gell cells, a charge controller, and jumper cables built from 1 ga wire and useing welding quick connect couplings. It’s very heavy so there is no chance of it blowing over, and is keeping up with charging duties in a busy barn yard, as a portable
12 volt power supply for testing rv/off grid equipment, and boosting tractors etc.
It works well enough that I am thinking of building a much lighter version for towing behind a bike, or pushed by hand.