Adafruit 328 Battery, Lithium Ion Polymer, 3.7V, 2500mAh, 2" x 2.55" x 0.30" Size

Added a picture that shows both the Adafruit 2000mAh and 2500mAh battery. However one is in a cardboard enclosure. It's worth the additional size if you don't have size constraints for your project.The Adafruit 2500mAh battery is what powers my 40+ hour custom bluetooth sleeping mask/headphones. It works beautifully with the Adafruit charger module.This is currently the biggest single cell flat Li-ion battery that Adafruit sells. If you need more power than this then go with big 18650 cylinder style rechargeable. Adafruit is awesome and full of quality products. For wearables it doesn't get any better than an Adafruit 2500mAh battery combined with an Adafruit charger. They are both chalk full of circuit protections so you can create a wearable with confidence.

It’s a battery! It works, has a high capacity, and is relatively inexpensive. What else is there to say?I used this to build a portable console inside an NES cartridge. This had more than enough juice to power my Raspberry PI, 2.2” LCD, and USB controller.

I wanted to use this for some cheap fpv goggles and I checked to see if had power and nothing upon further inspection I noticed that the positive and negative leads we're swamped so I lifted up the tab and switched negative to positive now the battery works

A very decent battery, for its size it has powered a Raspberry Pi with a 7 inch touchscreen, making it portable. I went to a bigger battery simply because i wanted more life out of the Pi when it was not plugged in, but it still lasted around 2 hours with no hiccups.

For what I used it for it works great considering it's size. I would like to find a slightly longer lasting one, but for its price and size I still get a few hours out of it powering a pi 3 b+. Good little battery.

I used two batteries to replace some Li-Po batteries in a Digital Labs 7 inch television. The Adafruit 328 batteries were actually smaller and had higher power density than the originals. They charged right up and the TV worked great again.

I am using the battery in a solar motion light, it seems to work fine & hold a charge when he he sun is down. Better then it did with factory battery.

Stores and disperses a charge. All that I could hope for in a battery. Adafruit is quality.