Banks Auto

I They're very light. They'rechargeable. They just take an 18650 cell in them. But they also have some other interesting features I also Now there's one downside to them and that is, as you can see, the current draw is often too low for it to stay on and so it will just do an auto shut off. And the worst part is that it varies significantly from one of these battery packs to the other. T But inevitably they cut out. Let's talk about these little battery packs for a second. They come in a lot of different shapes and styles. These ones have a single 18650 and they all have the same features. They've got a five volt boost circuit. They have an internal charge circuit. They do that voltage cut out if they detect no current. And they also have a over a short circuit protection, w They're super handy and they're also really inexpensive. These ones are about $2. These w 10, $1. 20. And t And it's a really nice little battery pack. It's a great way to power your projects. But as I mentioned, they all suffer from the same problem. And that is if they don't detect any current, they'll go ahead and just power off. And that will not, it's just not convenient for running an Arduino project. But as you can see, t And the reason it's been running with not So I'm going to show you how we can mod t All right. So what is t Well, t If you search for USB charge doctor, you'll see a lot of different variations. Now I These are about $2 to $3 a piece. You can get some that have more features that cost a little bit more and you can get some that just show the voltage and kind of cycle through the voltage in the current for about $1. And it's really helpful to have a bunch of these on hand. We also have two outputs. So we'll split one of these into being able to support two devices. And t So the very first t Now it turns out t So t If you just take a screwdriver and slowly kind of work on the front clip and then the back clip, you'll be able to pop t Now one of the t And the reason is, is it's got some little standoffs in there. So t One other the first t So go ahead and take those off since we're already in here and t So let's go ahead and talk a little bit about what we're going to do with that circuit. So what we're going to do is we're going to solder a resistor over the positive and the ground of t And what that's going to do is it's going to trick the battery pack into t Even though we just have t Now I've tested t Now that may mean that there'some out there that it doesn't work on and it'still not enough current drop, but if that's the case, you can adjust your resistor value accordingly. So let's talk about what resistors I picked and why I picked them. So I tested some different resistance values and I found that 100 ohms actually worked best for all of the power banks that I had. T Now, let's because t So let's go ahead and just run the math real quick and make sure that we're well wit So using Ohm's law, we've got 5 volts and we've got 100 ohm load. So if we do 5 over 100, that's 50 milliamps dissipation, w So if we do 5 volts times 50 milliamps, we get 250 milliwatts or one quarter watt. Now, these are a quarter watt resistors. So t And again, they're going to be inside of t So what I'm going to do is I'm going to actually solder two 200 ohms together here and these are going to be in parallel as part of t Now, right now I just have them tacked on there so I could test it. As you can see, they're kind of just flapping in the wind there. But what I'm going to do is I'm going to trim these down and I'm going to kind of twist them together and then I'm going to solder them in and then I'll put a little bit of capton tape on there to prevent them from shorting out on anyt But I did test t I started those two resistors in parallel and again, I've got two 200 ohm resistors, w And you're going to want to use your multimeter and just check to make sure. In my case, t So what I did was I just added a little bit more solder to the existing solder joint. T So just flow in a little bit of fresh lead solder and then it'll take that solder much easier. Make sure you don't short these pins out because they're very, very close together. And then I just twisted these two resistors together and I went ahead and looped them around and then I soldered the other side. So it's not a very difficult job to do. If you're familiar with soldering and you're used to soldering small things So now that I've got that on, I'm going to go ahead and put a little bit of capton tape on there because I don't want it to short out with the pins on the board. And I also don't want these two leads touch together because if they do, we're going to create a dead short across the five volts in ground. And that's going to trigger the overcurrent detection. So I'm going to go ahead and pull a piece of capton tape on there and we'll be all set. All right, there's the final version. I went ahead and put a couple pieces of capton tape on that so that it's protected. There's one underneath it so it's not shorting anyt Now I did test t I went ahead and ran t I kept checking on it periodically and it does get warm, but it's nowhere near anyt It's well wit And also just being inside that case, it's not going to cause any trouble. And because that case has a lot of room on the bottom, we're not really going to have to modify that case at all. T So let's go ahead and pop that back in. Well, there you go. It's a pretty quick hack, but And it'll work no matter what type of project. If it's an ESP 80266 or even some type of an Arduino or, The last t Now, technically doesn't really matter because we didn't change anyt It works exactly as it did before. It's just going to keep the display on now. So that's all I got for you. I hope you enjoyed it. If so, let me know in the comments or go ahead and let me know if you build it. I'd love to kind of see what your variations are as well.