V50 Always On External Battery Pack with Dual USB Ports - 13,400mAh

On all the time required for 50kg clock which is mounted 2.5M on wall. No requirement for scaffolding to change AA battery

Expensive, but perfect for my project that uses a Solar panel to keep battery charge while continuously providing power to small esp32-c6 controller that is controlling & powering a small water pump. Be aware that you need at Solar panel of minimum of 6V, 5W to charge this powerbank when you are also powering a separate device. if you just need to charge the powerbank then 5V solar panel will work.

We needed a power pack for the lights in our tent. It had to be always on even when the lights weren't working. This power bank works great. Is compact, hold enough charge for more than we need. Very simple to use, just plug in your device and its on! Easy to charge, great quality. Very happy with it.

I own a V20 and a V50. These packs are fantastic for my radio-related applications because they are 1) always on and 2) have overcharge protection. I use them to power unattended low power radio beacons (WSPR if you are interested). First, the "always on" feature is very important because the low power draw of the (0.2 watt) transmitters isn't enough to keep other Li-Ion battery banks operating (they turn themselves off). Second, the overcharge protection is great because I can semi-permanently hook the V20 / V50 up to a 20 watt solar panel (with a 5v buck transformer with USB output). One of my beacons has been operating (off-grid, of course) for 6 months now without any human intervention. For my sort of application - low power devices that are solar charged - the V20 / V50 saves me having to purchase a charge controller and lifepo battery. Using the V20/V50 is both cheaper and less bulky (and easier to fit and wire up in a weatherproof box).

If you are looking for an “always on” portable power source this is it. Other reviews touch on its purpose in solar or other scenarios. I purchased because I was looking for a portable power supply that didn’t require me to press “on” and merely drawing power by connecting a device would enable charging. This device does that. However, since it will always send a trickle of power if you don’t pair this battery with a solar panel or other continuous charge source it will discharge over the course of a week. This isn’t a design flaw. But if you are just trying to charge a phone it’s probably not the best power bank. That said, this tech is truly impressive. Pass thru charging. The ability to continuously trickle charge. The use of lithium ion instead of lithium polymer. This is engineered for a very specific purpose and I don’t think any other company is solving this. This takes IoT to new levels.

I think the price is to high, but it's good . I use it for a Blink camera, in a place outside the house without power. I didn't connect a solar charger to the battery because it's a huge capacity for a camera supposed to use 2 AA batteries for 2 years in a moderate use. After a day of use only, everything is working good.