LP 9V Rechargeable Battery Pack, 2-Pack 800mAh Li-ion 9 Volt USB Battery with Micro USB Charging Port for Alarms, Smoke Detectors, Flashlights, Guitar, Keyboard & More

works very good

I love these things! 9V batteries always feel like a hassle—either they drain too quickly or sit around too long and die before you use them. These rechargeable ones completely fix that issue. I use them in my smoke detector, carbon monoxide detector, and car remotes, and they work great. They charge fast, have a handy LED indicator to show charging progress, and best of all, they charge via USB—how cool is that?! No more wasting money on disposables. Highly recommend! Nice little case, actually reused for something else and kept it.

The 9v lithium ion battery is working as intended on any devices which are not sensitive to the exact voltage as these rechargeable battery only provides 8.4v at 100% charge.It cause my multimeter to be off by about 2% comparing to using carbon base or alkaline battery but that doesn't border me too much since since I don't need top level accuracy.The best part of it is that I can have the battery quickly recharged using a USB cable without having to use a 9v form factor charger.

Exelente

The product is good. No doubt about it. However, I just wanted Lithium Batteries. I have a charger. That is why I returned it.

9 V lithium rechargeable batteries Great value for a highly rated battery

I ordered one for myself and one for a family member, and they both stopped working after just a few times using.Would not recommend this item

I’m a guitarist, and I live and die by 9 volt batteries, especially for my acoustic guitars. Which, I have about 7 that I rotate through with on-board electric that require 9v batteries. These are outstanding, and work for longer than I expected, charge quickly, and for the price, I was impressed. I’m really pleased with this product. I’m sold, and am planning to buy another set for when the batteries I haven’t changed yet run out.