Okay, so I’ve been meaning to build a universal power bank for a while now. You know, one of those things that can charge pretty much anything – phones, tablets, maybe even a laptop in a pinch. I finally got around to it, and let me tell you, it was a bit of a journey.
Getting Started
First, I gathered all the parts. This took a bit of scrounging around. I had a bunch of old 18650 batteries lying around from old laptop battery packs. That’s key, you can salvage some good cells from there if the pack isn’t totally dead.
- Batteries: Like I said, old 18650s. I made sure to test them individually to make sure they could still hold a decent charge.
- BMS (Battery Management System): Super important! This thing keeps the batteries from overcharging, over-discharging, and generally keeps things safe. I picked up a cheap one online.
- Charging Board: I got one that supports USB-C PD (Power Delivery) because that’s the future, right? It can handle different voltages, which is what we need.
- Case: I just used a plastic project box. Nothing fancy, just something to hold everything together.
- Wires, Connectors, Soldering Iron, etc.: All the usual stuff you need for a basic electronics project.
The Build
The first step was connecting the batteries in parallel. This increases the overall capacity. I carefully soldered them together, making sure the positive and negative terminals were lined up correctly. A mistake at that moment will be painful. Seriously, be careful when soldering batteries – they can get nasty if you short them.
Next, I connected the BMS to the battery pack. This involved soldering more wires, following the instructions that came with the BMS. It’s crucial to get this right, or the whole thing could go up in smoke (literally).
Then, I wired up the charging board. Again, more soldering. I connected the input of the charging board to the output of the BMS, and then added some output connectors – a USB-A port and a USB-C port. I might add more later, but that’s good enough for now.
Testing and Finishing Up
Before I stuffed everything into the case, I did some testing. I plugged in my phone, and… it charged! I tried my tablet, and it worked too! I even tried my laptop, and while it charged slowly, it did charge. Success!
Finally, I screwed everything into the case, added some padding to keep the batteries from rattling around, and closed it up. It’s not the prettiest thing in the world, but it works! It’s a bit bulky, but I can now charge my devices on the go, no matter where I am. It’s saved me a few times already when my phone was about to die.
Overall, it was a fun project. It took a bit of time and effort, but it was totally worth it. If you’re thinking about building your own power bank, I say go for it! Just be careful, do your research, and double-check your wiring. Safety first, folks!