DIY Power Bank - Make Your Own External Battery Pack,2 Output 3 Input (Mirco,Type C,Lighting) - Battery Not Include (Black)

I have around 15 of these black and blue, love them

Bought a bunch of these through temu and they are out of stock there so bought this one here. The difference between this one and the ones at temu is that this one snaps together and so the cells you put into it, be sure they are healthy and wont need to be swapped out in near future, as the 6 that I bought through temu had screws to screw them shut and if needed unscrew to replace failed cells.

Years ago I replaced a laptop battery and took the battery case apart. There were 9 flat top lithium 18650 batteries inside. I had a charger and charged them all. Then they sat on the shelf for a really long time; years. I saw this power pack and hoped it might work with the old, recycled cells; so I ordered it. When it arrived, I guessed about the battery polarity and put 8 cells in, all the same orientation. I tried to shut the cover, but it was not easy, so just left it while I tried to charge batteries in the power pack.The usb micro cable they supplied is defective so the display didn't change when I plugged it in and I could make no sense of how it was supposed to work. I tried another usb cable and then the dispaly changed and showed power "IN" rather than "OUT". So bad on them for a bad power cord.The initial charge from the stored recycle batteries was 70% and it took hours to get to 100%, fully charged. I have been powering a recycle blue tooth speaker that had built in non-servicable batteries which I removed. After more than 15 hours of speaker use, the charge is down to 50% and I will take it down to 20% or so, and do another full charge in order to get a deep charge cycle. The power pack is flawless for my purpose of principally powering an otherwise good blue tooth speaker.Now for my headline: "I broke it on purpose". I am referring to the fastener tabs on the cover. Since I was using recycle batteries, and selected 8 of 9 cells on hand, I did not want to lock the case, if I needed to switch out a battery. I had read in other reviews, that once snapped shut, it could not be opened without damage. I figured better to disable the fasters and tape the power pack shut, than have to break it to access the batteries. Otherwise it becomes obsolete when the batteries eventually need replacement. So I used side (wire) cutters to clip the fasteners from each side to remove the botton of the "U" shaped fasters on the cover, and three strips of electric tape fasten the case shut. I don't mind the tape though a fastener that could be opened would be better in my opinion. With fasteners that allow opening and a working usb cord, I'd give 5 stars.So that's the story and I love being able to reuse things like old laptop batteries and a great bluetooth speaker.Hope this is useful for someone.

I already wrote this review once, but amazon denied it so this is gonna be much less organized.The power bank appears to have a 1A port and a 2.1A port, though they behave similar.The input current with the included apple cable is miniscule (that cable also refuses to work on the iphone I tried it on). The input with a quality charger and usb-c cable is acceptable but slow. About 6 watts. With a full set of cheap batteries (1.5ah) this bank could hit 45 wh, thats 8 hrs for a full charge. Higher quality cells like I am usually are over double that.I was able to pull about 11w out of a single port before the power bank would shut down, but the voltage would drop significantly in doing so.Not a fan of the case being (effectively) permanently sealed once closed, especially woth the low input current.Someone mentioned that the batteries will get hot if you put in unbalanced cells.......um, ya? If you don't know that you need to balance charge and capacity check the cells you are putting into a parallel group you shouldn't be touching this product.

Well I finally got the right batteries for this. Apparently, this requires "non-protected" flat top 18650 types. So I put them in and then tried to place the top. Like the directions said, that can be an issue because it is apparently impossible to remove the top without breaking the retainer tabs. The directions didn't tell me that it's best to insert the end that is on the long face of the front. Those tabs are shortest and are most easily inserted first, then the end with the ~10mm flange which is the front right side of the cover that has some flex will snap into place. 50/50 chance and I muffed it. When I pried it apart to operate the alternate I see that 1/2 of the tabs are busted. So, 2 out of 4 tabs per side might be enough to keep this closed (maybe) but if I drop this there will be batteries everywhere.Ok, so I bought another, but there aren't many others out there, but it would take much to beat this. I'll have to pull some tape over that seam so it does just fall apart for vibration.

Day 1 use is pretty good. Little finicky putting the cover on, but otherwise works well. I scrap laptop batteries and damaged power banks, leaving me with a lot of 18650 batteries with plenty of life still in them. This makes it quite easy to give them another purpose in their life. It is possible to remove the cover using plastic shims and prying tools should you need to remove, replace, or test individual 18650 cells.I'd recommend doing a charge/discharge test on the cells to get their voltage and capacity prior to installing them. Not all 18650 batteries have the same capacity, it helps to match them and gives you an estimated capacity of the DIY battery

It's ideal for a DIY person like me.This is a convenient way for me to use my leftover 18650 cells from other projects.I made sure my 18650 cells were the same voltage and installed them into the case.I tested and verified the assembly before I attached the lid.I checked the basic functions, then completed the assembly.I am satisfied the pack works as expected.I like the convenience of assembly and the simplicity of use.This is an ideal way to make something useful from leftover 18650 cells.