diymoreLi-ion Battery V3 Shield 1 Holder 3V/1A 5V/2A USB Power Bank Battery Charging Module 1865O Battery Holder

If you're looking for a reliable and versatile battery holder for your electronics projects, the diymore 18650 Battery Holder Double Li-ion V8 Battery Shield Micro USB is an excellent choice.Upon receiving the product, I was impressed with its sturdy construction and easy-to-use design. The holder is compatible with two 18650 batteries and features a micro USB port for convenient charging. The V8 battery shield also ensures that the batteries are protected from overcharging and short-circuiting.One of the standout features of the diymore 18650 Battery Holder is its versatility. It can be used with a variety of electronics projects, including the Raspberry Pi, Arduino, and other microcontrollers. The holder's compact size also makes it ideal for portable projects that require reliable and long-lasting power.In addition to its versatility, the holder also boasts excellent battery life. When fully charged, the 18650 batteries can provide hours of uninterrupted power, making it an ideal choice for projects that require consistent and reliable power.One potential downside is that the holder may not be compatible with all battery types, so be sure to check the specifications before purchasing. Additionally, the holder may not be suitable for high-current applications, as the batteries may not be able to provide enough power.Overall, I would highly recommend the diymore 18650 Battery Holder Double Li-ion V8 Battery Shield Micro USB to anyone in need of a reliable and versatile battery holder for their electronics projects. Its sturdy construction, easy-to-use design, and excellent battery life make it a top-performing and reliable choice for a variety of applications.

Nice way to provide back-up power on a USB-A line. With both batteries installed, I could power an arduino UNO3 for about 2 days. There are some odd things; The batteries are charged via the usb-C or micro usb, and the battery power is available out the USB-A port. There are also several 5-volt and 3.3 volt solder holes available on the board, so if you want to solder on your own connectors, you can. Overall, its a nice way to keep your arduino running without a computer.

Here's the good:The DC/DC converters are very efficient, both the 5V and 3.3V - like 94-95% across the whole range of input voltages that a battery is likely to generate. This is WAY better than a lot of DC/DC boost converters you can buy out there.Here's the 'meh':There are a set of LEDs on the bottom. For low current, battery powered devices, this is wasteful and consumes power for no benefit. They are easy enough to remove once you have the device operating properly.The device does not automatically turn when a battery is inserted. You must press the "enable" button once to turn it on.Here's the bad:There is an auto-sense that detects when there is no power being consumed and shuts the unit off. The definition of "no power being consumed" means less than 90mA, which is really quite a lot if you are using this device for a low-power microcontroller design. After about 30 to 35 seconds of "no-load" (<90mA) the unit will shut itself off.They provided a switch to "disable" the auto-sense, but this works by placing a fixed 90mA load on the unit to insure that there is always load above the shutoff threshold. For a long-lived battery device this is unacceptable as 90mA is more than my target design consumes and would drain the battery very quickly. This is a very poor, inefficient solution to the problem and not very good engineering.There is a solution to this, but it is a little hacky and requires cooperation with your target device. I added an external circuit (a single 2N7000 and a control line) to emulate a button press on the "enable" button every 20 seconds or so. When my system is running, I have to make sure that this circuit gets activated (pull the enable pin on the switch low for about a tenth of a second) every 20 seconds. This appears to reset the "no-load" timer and you get another 30-35 seconds. Do this every 20 seconds or so and the unit will run indefinitely at very light loads (my specific design consumes about 2mA nominally).You can't do it too fast as two quick presses of the enable button are what signals the device to shut off.I gave the unit 4 stars because the DC/DC converters are so darned efficient. If I had not been able to do the button-press emulation trick to keep the unit running under light load it would have gotten one star.I hope this helps anyone trying to use this DIYMORE battery shield for very low power designs. It you have the knowledge and provisions to tickle it appropriately it can work well, and be very efficient. If not, then the fixed load, or auto-shutoff might make it tricky to use effectively and efficiently.

New info: I like these well enough to order more, but now both unit three and it's replacement unit 4 have been damaged upon arrival,.. I'm returning again for replacement hoping third time is the charm... This last one both sides of the 5v USB output socket where completely crushed/scraped to death. No way this got past QCOn a brighter side Iv found quite a few uses for these regurdless of their shortcomings.Original review:As others have mentioned the 90ma requirement to stay in always on mode is not ideal.. but also note this can't be used as an uninterruptible 5v psu either as there is a full 4 to 5 second power output delivery gap from the point the charging circuit losses power to the point the 5v battery power cycles up on the 5v output.In addition it's not a very good charging other devices circuit either only able to charge dumb devices, any thing that requires a handshake won't charge off of it at a decent rate, (aka most modern cell phones)All that together limits what this circuit can do more than I expected when I purchased it, although still has potential...Oh, and I did blow one up,.. I'm not sure if I made a connection mistake while tinkering, or it fried on its own.. I double checked everything after it went out ... I'm about 75% i didn't make a mistake...If only it was uninterruptible.