I purchased this power bank to use it in an application different from most people. I wasn’t looking for a battery to charge my devices. Instead, I was looking for a way to keep my security cameras powered in case of a power failure. To do this, I needed a power bank that plugged into the wall to remain charged while simultaneously being able to deliver power to my camera. Many power banks cannot simultaneously be charged while outputting power to other devices.General Review:- Has a battery percentage display to know how much power remains- Can be charged while simultaneously charging other devices- Can be charged by plugging it into a wall outlet or through USB C (cable and plug not included). The built-in wall outlet is for North American outlets. However, the specifications indicate the input is 100-240VAC, 50/60 Hz which means it can be charged anywhere in the world without getting damaged if you have an adapter to convert the plug. This means this would work well for travel.- Comes with a travel pouch- When plugged into a standard 2-plug outlet, it does not block the use of the second outlet- Includes a 4” long built-in USB C & Micro USB cable and a 4” long built in Lightning cable to charge most devices. These built-in cables are only useful if you remove the battery from the outlet and do not intend to use the device while it charges as they are too short.- The built in USB C, Micro USB, and Lightning cables can output 5V @ 2.4A. I tested and confirmed that this charges a standard Android phone and an iPad. This however is insufficient to charge a larger tablet such as a Microsoft Surface Go. In fact, most power banks are not capable of charging devices like the Surface Go.- In addition to the built-in cables, it has output ports to connect a USB-A or USB-C cable to charge your devices. These output 5V at 3A. I tested the USB-C output and found it was able to charge a Microsoft Surface Go. I charged a Surface Go 2 from 71% to 100% when the battery was disconnected from power. This in turn dropped the Veger battery from 100% to 71%.- In terms of electrical safety certification, it displays marks for CE (conformity for use in Europe), FCC (electromagnetic radiation conformity in the USA), and PSE (electrical and EMI safety in Japan). However, it is important to note that CE, FCC, and PSE follow a self-declaration procedure which allows a manufacturer to claim that it meets requirements without the need to be tested by an independent test laboratory such as CSA, UL, TUV, or ETL (which would provide more assurance in terms of safety as you are not relying on the manufacturer to be telling the truth).Performance as a Battery Backup for a security Camera:For my test, I connected a Wyze Cam V3 camera to the USB-A port of the Veger battery. With the battery plugged into my 120V wall outlet, I waited until the battery was at 100% and then disconnected it from power and observed the battery level drop over time. I found the following:- When I disconnected the battery, the camera reset. It took 1.5 minutes for the camera to record again. This means the power output of the battery drops momentarily when disconnected from power. This device would be better if it could maintain the output power when disconnected.- When reconnecting the battery, it caused a short 2 second disturbance in the recording (missed footage) but did not reset the camera.- After 12 hours disconnected with only the Wyze Cam V3 connected, battery power was at 59%. After 24 hours it was at 17%.- Based on the data retrieved, I determined that with the Wyze Cam connected, power drops linearly according to the formula:Battery Power % = 100.36 – 3.4575 x Time (h)Where Battery Power is in percentage and Time is in hours. For example, to determine the battery power after 4 hours, it would be 100.36 – 3.4575 x 4 = 86.53%.- Using this equation, if you solve for Time and a battery power of 0%, I can determine that the battery will last approximately 29 hours before the camera shuts off. That is a pretty good backup time.Summary:Overall, this product works as a battery backup for my security camera and as a charger for my devices. It would be better if the power output did not drop temporarily when disconnected in order to keep my camera powered continuously, but it wasn’t designed for this purpose so I can’t complain.As a device charger, one big plus is it was capable of charging my Microsoft Surface Go products. Most power banks are not capable of doing this. It’s not a fast charger, but it worked. The built-in power cords are short, but helpful in a pinch if you forget to bring your longer cables. Overall, I am happy with my purchase.