hpr-knowledge-base/hpr_transcripts/hpr3628.txt

Episode: 3628
Title: HPR3628: Building a Mobile Computer Battlestation: Extended Power Supply
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr3628/hpr3628.mp3
Transcribed: 2025-10-25 02:23:26

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This is Hacker Public Radio Episode 3628 for Wednesday the 29th of June 2022.
Today's show is entitled, Building a Mobile Computer Battlestation Extended Power Supply.
It is hosted by mechatraniac, and is about 21 minutes long.
It carries a clean flag. The summary is Mobile Computer Battlestation Part 116 Cell Power Supply and BMS.
Greetings. This is mechatraniac, mechatraniac's maniac.
And if you're listening on HPR, check out my bitchute channel, bitchute.com forward slash channel, forward slash mechatraniac.
If you're listening on bitchute, you check out hprathackerpublicradio.org.
And you'll be able to hear my podcasts ahead of time.
So today, going to be starting the build on my mobile battle station, I had a catastrophe with my power generation supply.
If you look at figure 0.1, that's the battery bot.
You can see on the left is the boost converter that supplies power to my laptop.
It brings the 16 volts on the battery bot there to 19 volts for my laptop and get a bit charged out of that.
Figure 0.2 shows a detailed shot of it charging the solar panel underneath it.
Figure 0.3 shows the 4s3 battery pack made out of 18650 cells.
4 series, 3 parallel is what that means, 16 volts out of that.
So I had compounding disasters after the boost converter died.
I don't know why I should have had it covered or something, I guess.
Because it fried while I was doing something else, so probably inadvertently shorted something somehow.
But day or so later, I noticed the battery pack on the battery bot was discharged down to 0.
I guess that's what happens when you don't use something, it falls into calamity sometimes.
If you know anything about lithium ion cells, that's a no-no.
Getting any cell down less than 2 volts is damaging to it, so 0 volts for the whole pack is pretty bad.
About half of them were dead at 0 and the other half were recoverable somewhat.
Actually completely recoverable, I think.
But the other ones I'm going to have to try, especially means that you can zap them with 20 volts or something like that and bring them back.
So we'll try that.
But anyway, I was talking about building the mobile battle station.
Oh, and by the way, the chip shortage seems to be done.
I don't know, or hasn't hit yet because I ordered replacement boost converters and they got here within a week.
So if you look at Figure 1, Super Nintendo System 5 builds really good computers.
I remember calling them way back when for an obscure question about the type of memory on a video card that they made.
And there was no touch tone tree person answered right away and knew the answer.
She just knew it right away.
So a fan of that company, I guess.
So yeah, they also make a nice box, nice cardboard box that the laptop came in.
I covered it in some black duct tape to make it more hardy.
And going to build the battle station into the spare compartments on this.
So if you look at Figure 2, that's the concept there.
I've got 16 cells arranged and they fit quite nicely in that little compartment right under where the laptop sits.
So you can take out that thing.
I'll probably like wrap it all up at some point.
If you look at Figure 2.1 and 2.2.
And Figure 2.2, I lift that flap.
That's where I'm actually going to put the battery management system.
So right now we're building extra functionality into this computer getting more hours out of it.
Figure 2.3 shows that it's nice and flat.
So they fit quite perfectly actually.
It's like it's made for the 18650 cells to be in there.
And Figure 3 shows me charging up.
I've got a battery management system temporarily hooked up to a four pack just so I can charge four at once.
I want to get them all charged up.
I got a single charge system as well coming from buck converter down to five volts on the right of Figure 3 with a single 18650 cell there.
And there's four under the battery management system on the left.
You just can't see them.
So I want to get them all charged up and all at the same voltage before I finalize this build.
Figure 4 shows it charging from.
It shows the BMS charging from my smaller solar cell solar panel.
I mean I have a few solar panels.
Figure 5 is a fake photo of me soldering.
I can't hold the camera and solder at the same time because I need to use a tool to pin them down but you get the idea.
Figure 6 shows that I've covered part of that box assembly with some nice duct tape and I taped the battery management system in there.
If you look at Figure 7 you can see where the wires go through.
I drilled some wires through.
One, two, three, four, five wires and that's going to be all going to the BMS.
Okay, if you look at Figure 8 we've got the four packs.
I'll hooked up and all the wires soldered as well might be hard to see but they're all hooked up.
Figure 9 shows them all connected to the appropriate spots on the BMS board.
And these BMS boards are pretty good.
I've had these for a while and I haven't blown them up yet so they can take a bit of punishment.
At the top where you see the plus and minus that's power in from the jack.
So barrel jack so I can either plug in that little solar panel.
I showed you earlier or plug in a 19 volt charger.
The solar panel produces up to 21 volts so it works just perfectly with this BMS.
I'm going to have to shorten that wire on the bottom left there.
It's kind of sticking out.
Figure 10.
Just measuring the voltage on the completed battery pack.
It's all ready to go.
And you can see to the right where the barrel jack plug is.
So it plugs into that shrouded in white tape.
And that's where it charges from and distributes the charge to the individual battery packs.
I was thought a BMS actually like controlled the discharge but no there's no breaking of the contacts.
It just charges them.
So figure 11.
Better look at the wire harness there.
Warrings looking pretty good except for that one at the 12 volt spot as I mentioned earlier.
Figure 11.1.
I've got a single strand wires hooked up to the ground and the 16 volts coming from that red wire.
They're pretty thin.
My theory is here.
If some are short so the way they'll burn up.
They'll burn up harmlessly.
No fuse needed.
Figure 12 is the boost converter and that goes from that red wire.
I'm just using alligator clips right now until I put a switch in there.
So figure 12.1 you can see that it's plugged into the laptop and charging.
I blew up a bunch of these like the first time when I was using with the battery bought.
I just die one after the other until I hooked up the buck converter.
I had a buck converter on and somehow that kept it from blowing right away.
So I figured I must be getting damage from current spike from the first turn on.
So I put a choke like a fairite to a Toroid with one wire wrap.
You can see that at the bottom on the red wire on figure 12.1 and seems to have helped.
Figure 13 shows it charging outside.
So it seems to be working pretty well.
I think I might tack on one more on each of those and make it a 5s4.
It's a 4s4 right now.
Just to get more capacity out of it.
So it charges the laptop pretty much completely.
I noticed that one of the packs is less than the others.
They're all 3.7 right now but there's one that's 3.4.
So it could be I've got a bad cell in one of those so I'm going to replace that.
If you do build one of these make sure that you check it a few times.
The first time that you try it out make sure none of them are getting hot or anything.
Make sure you check the voltages make sure none is depleting faster than the others.
So I've noticed one is depleting faster than the others.
Hopefully that will be easily resolved with another.
So these are all like 4.11 to 4.14.
That's a capacity that they hold.
Maximum capacity on these when they're new is 4.2.
So these are a little bit damaged already.
I was going to use the ones that are like 4.1A or 4.17 around there.
But I didn't have enough of them charged up and I was in a hurry.
I wanted to get this done so these are slightly less healthy cells but I don't know.
Maybe the workout they'll get will get them healthy again.
I could always replace them with healthier packs at a later time.
Just a matter of getting them all charged up and just swap this one out and maybe use this one on a robot or something or some other project.
Oh, a tip, a last tip on figure 13.1.
I had a heck of a time with this thing because the barrel jack on the solar panel is smaller in diameter than the one on the computer power supply that I used to charge it up when I'm using the generator.
And I'd always have to like after plugging into a computer supply it wouldn't quite make contact well enough for the solar panel one.
So after lots of pain like prying up the ground connector you know because every time it would be bent down by the bigger computer power supply barrel jack.
I decided to smarten up and widthen the diameter of the solar panel one so I put a little wire on there with some solder.
And that works perfectly so I don't hate barrel jacks quite as much now.
Alright, so that's the first part of filling this mobile computer battle station.
A lot of other compartments in this box and I'm going to be putting in a buck converter as well so down to five volts and have some USB out, have a router with Wi-Fi.
And have a orange pie zero.
I might put my Raspberry Pi 3 in there, I don't know, I'll put the orange pie zero in first and that's going to be my Wi-Fi.
So no more connecting to public Wi-Fi with my laptop, it's all going to be going through my orange pie zero and everything's going to be going through tour on that.
So I've got tour running on the orange pie zero.
So I'm going to take the Wi-Fi and there's a way to get past that portal capture whatever it is when they make you sign up on public Wi-Fi.
There's a way to bypass that so that'll be fun.
But right now I've got a functional charger, not perfect, but like I said we'll get that one pack sorted out and should be awesome.
Especially when I add another one to it and it's 5S4, that should be good for a couple of charges I'm hoping and especially when I get the better quality cells in there.
But I might stick with this for a while.
Never know, we'll see.
Yeah, so I might even put a breadboard in there and you know, put in stuff like ESP8266 and stuff, how all kinds of fun mischief running.
You know how it go.
All right, this has been mechatroniac, mechatronics, maniac, rage, PR.
Check out bitchute.com channel mechatroniac.
If you're listening on bitchute, check out hackerpublicradio.org.
We'll see you next time and we'll get more robotics going, more post-apocalyptic robotics and more of this battle station build.
Ciao!
On this address status, today's show is released under Creative Commons, Attribution 4.0 International License.