Upgrading My Old EDC Power Bank
Introduction: Upgrading My Old EDC Power Bank
For over 4 years I have carried this power bank in my pocket every day. For me the size is perfect because it is small enough to disappear in my pocket but large enough for a decent power boost. I carry it alongside an incharge cable on my keys so I (as well as my friends and family) am never without power! Lately however, I have noticed a drop in battery life and although I absolutely love the form factor, this particular power bank always had some featured I did not like... so I fixed them!
To start with, I always carry a powerful flashlight on my keys and everyone now has a flashlight on their phone. Hence I have never once needed to use the light on this powerbank. So although a UV LED is not much more useful, at least it is something I don't already carry two of!
Modification 1: Replace the white LED with a UV, blacklight LED
I also always disliked that the light from the four blue LEDs to show charge level would bleed into the next bar of the display making it near impossible to tell what battery level the pack was on. I actually tried to fix this when I first got the power bank by sticking some folded up black paper in there (which you will see in a later step) which hardly helped.
Modification 2: Replace the 4 blue LEDs with red, yellow, and green LEDs. As well, make proper dividers to stop the colour bleeding.
And finally, the main reason for going ahead with this project, the battery life.
Modification 3: Replace the two old 2,200mAh batteries with two brand spanking new 3,500mAh batteries!
This has been one of my favourite weekend projects in a while. It is just one of those rare projects for me where I had the idea, ordered the parts, and a week later it was all done exactly as I had planned. In fact, I have enjoyed the final product so much in the last week I have been carrying it that I built up another one and will probably give this older one to my father to keep in his car.
Like most of my other projects on here this is less a "how to" and more a "how I did it". 231
Of course you could go out and buy all the same parts however I am more interested in just sharing broad ideas rather than exact instructions. This is a simple project so I will try my best to keep it short.
Step 1: Taking Apart the Power Bank
To take the power bank apart I started in the bottom corner and pried up just with my fingernail. Then I stuck the side of a plastic ruler in and slid it up to pop the case apart (a proper spudger tool probably would have worked better). Once the two halves of the case are apart there is just one screw to take the electronics out (takes a little wiggling thanks to the LED and button). I had already had the case apart to check if these mods were possible before buying the parts but I wish I could have shown you the layer of dust inside when I first opened it up.
The first thing I do once the electronics are separated is desolder the battery to prevent myself accidentally shorting the LiPo battery and starting a fire. I desolder the wires from the battery rather than from the circuit so there is no chance the battery can short out through the wires. Connecting the circuit to a power supply between about 3.2-4.2V (the voltage range of a standard LiPo battery) we can see that everything is still working as expected. From now until the final step I will be testing everything with the power supply instead of the final batteries as again, an accidental short circuit could very well be a disaster. However as long as you check for continuity before putting the battery back into the circuit and you don't try modify the circuit with the battery connected, you should be safe to test with the battery.
In the final photo you can see the second power bank I took apart. It had some funky white goo holding the batteries in place but carefully twisting the case back and forth, I slowly broke the case and batteries free.
Step 2: Modification 1: Replace the White LED With a UV, Blacklight LED (part 1)
I bought my UV LED from a small local LED supplier here in Australia. The part number is VAOL-5GUV8T4 and I found it on RS components as well for a little more so I assume it is a popular LED for these kind of applications.
I desoldered the original white LED and temporarily soldered the UV LED on for testing.
I was hoping that the UV LED would work without modifying anything else but it was very dim and my power supply showed the LED was drawing between 10-20mA which is not very much for an LED. 635