5V-2.1A Power 18650 Holder Organizer Batteries Box for Electronic DIY Holder DIY Bank Holder Case (Black-Regular Version) (Black)

For ~$7 it's a good buy. My first impression was that it seamed kind of cheap, but once I loaded the batteries, assembled the case, removed the plastic film covering the readout, it looked pretty good. It indicated that the cells were at 100%, the flashlight worked, and I plugged a USB cable and all was good. I'm using this as a battery bank that I can charge via small solar panel, or hand crank generator. With INR-18650 35E cells my full capacity will be 28 Amps @ 3.7-4.2V. That's plenty of storage for home, car or camping, with my gear. LED flashlight is not very bright, but it's handy in a pinch.

I had a bunch of 18650 batteries laying around and was looking for a use for them. It holds 8 so it provides long lasting power to charge a device. The lights aren’t super bright but are a good additional feature. Solid construction and small enough to fit in a pocket. My only complaint is that the USB-C is not an output, but it is good that it is an input to charge the batteries. Will be buying another.

I purchased this because I had a bunch of these batteries laying around for my camera gimbaks. I like even using this as a battery case.

Not too bad. Doesn’t support low power draw though (shuts off) for things like small Bluetooth speakers and other devices that draw little current. Took my 8pc unprotected button top batteries just fine. Waiting on a set of new flat tops to use for more mAh though. A tad challenging to open the unit but nothing a little patience didn’t fit. Might buy another one.

AVOID This thing houses 8 18650 cells. Yet, it boosts the output from a parallel connection of the batteries to the 5V output for use. That's not very efficient. Also, it claims a 2A charge but i have only seen it get to 1.1A, then shut itself off. Even if using this unit to just CHARGE the cells, it only brings them to about 70% total charge at a slow rate before claiming 100%.

How do you open it to put the batteries in? Wtf

What can I say? This is the best priced DIY power bank out there when it comes to all the options available. Great fit and finish for the price and is nice and tight. So if you’re looking to build your own power bank and save a few dollars this is your ticket!

Of the three different devices like this that I've purchased from Amazon all of them seem to suffer from two different maladies: it doesn't they never seem to fully charge or discharge the 18650s that you put in there.. my test the capacity of my battery is before I put them in the device like this and I am never able to charge up the amount of devices I should be able to, basically the math never works out also I've never been able to get the full current that they claim it discharges. that in this park was no different but it works. other than those little quibbles it works as described and is a decent price