Review on 🔋 Versatile 4-in-1 Board UPS: Efficient Raspberry Pi 18650 Battery Charger, 3.7V to 5V 12V Conversion, Built-in Protection (5V 15W Output) by Thomas Drew

POSITIVE: 1. Features as advertised.2. The size is perfect for its purpose.3. That we need to short out the SW pads with either a jumper or a switch was perfectly clear in all versions of the instructions. Well done. NEGATIVE: There appear to be at least three different versions of this product. The website shows one thing, the instructions page that came with the device I received shows another, and the device itself was still the third version. This manufacturer will do well if they 1) update Revain with photos of the device they currently ship and 2) match the instructions and devices they ship in the same package. All you have to do is put on your thinking cap and figure out what's what. Overall, this UPS supplies 5.06V DC from a single 18650 battery, so I'm fine with that. Haven't tried charging the battery with it yet because I don't have a ready-made way to do it, but I'll update this review when I do. UPDATE: I had time to solder the micro USB socket. to the 5V charging inputs of this little device and it works like a charm. You can use this item to charge your 18650 batteries or use me as a tiny UPS for your low power projects. For now, I'm so pleased with this simple little device that I'm increasing my rating from 4 stars to a full 5 stars, although I still think someone who is fluent in Chinese and English can make a fortune in the technical writing business . . I measured and uploaded the charging specs of this device using a 1 amp USB charger, like the image that accompanies this review. It answers some of the questions people are asking, and that should be in the datasheet anyway. This UPS shuts down when the battery voltage drops to approximately 3V. From this point it takes about 6 hours for a 1A charger to bring them back up to the full 4.2V level. more or less linear. The circuit or system powered by the UPS can monitor the battery level on the B+ pad if appropriate level conversion is used. The photo shows the switch, which I also soldered onto the board as per the datasheet. It just switches the output voltage on and off. The UPS can be charged regardless of whether the output power is on or off.