diymore Li-ion Battery V3 Shield 1 Holder 3V/1A 5V/2A USB Power Bank Battery Charging Module 18650 Battery Holder

This battery shield will become a staple in future projects. The comments that state they put the battery in wrong and it caught on fire.... Learn from others mistakes and double check that positive and negative are aligned correctly, also use flat top batteries and the fit is perfect. I had a longevity test running and it has not turned off a single time in over an hour until the battery could no longer power the LED strip. The case comes with a USB C input which isn't mentioned, but very welcome as I don't like using USB mini. There are 5 red LEDs to indicate power level of the battery while being used and while charging. As I was using this to power a 6ft strip of LEDs, I don't think they affected power levels to any significant degree. Suggest making sure you purchase a higher mAH battery so that it will last longer between charges. Typical I have seen is 3000 but found one that's 9900 I will be trying out.

I got this item to test capacity of recycled 18650 cells. Combined it with a USBC power meter and an old phone as load. Seems to work OK. Manufacture was less impressive - see photo of poor surface mounting.

Swappable common battery, charges from USB and can give USB power. Has 3v and 5v so it can power at least the portable projects. Perfect for pi or Arduino projects. I'll be buying more eventually.

I got the version with the push button. On this unit there are 5 leds that are always on, draining the battery. That makes it unusable as a battery power source. You're better off just soldering wires to your battery (or running to a voltage regulator). Moreover, it will not function as a UPS because when you unplug the input cable, it takes a second or two to switch the output to the battery. This means, for example, if you have an arduino plugged in to the usb connector and the power to the input connector fails, the arduino will reboot. The older unit, which had a switch instead of a push button, did not have these problems, but the quality control was sub par. Too bad, because it could be a useful device. I just don't see any use for this board in its current design. I will look elsewhere for solutions to powering microcontrollers.

The unit uses a generic power chip and shuts off if low loaded. Their workaround is putting a resistor across the output, effectively wasting battery capacity. The micro switch can remove the resistor from the circuit when the load is enough to keep unit awake. The USB-C is input/charging only. So the outputs are the USB-A on the end and the solder points. The 3V output measures 3.3V

works like it should. just to confirm to some people it ONLY take flat top 18650 batterys.

Using a 5W USB solar panel, I was able to charge up a recycled 18650 from an old laptop pack. I am testing this with an ESP8266 and temperature sensor connected to Home Assistant. The board looks well built and is a great way to add a battery to electronics projects.

This is a nice unit, and I like the separate ports for charging. My only complaint is that power is controlled by a pushbutton on the board; it would be great to have an option for a remote power switch. I'm using this to power a portable testing device using an Arduino microprocessor, so accessing this battery board is a little tricky. Also, be sure to get a good quality battery for it.