9V USB-C

These batteries paid for themselves in the first 10 days. They're well worth the price.

What a brave new works we are living in! Just plug right into the battery and charge! So awesome. They seem to die a little faster than traditional ones but that’s fine. Been using for over six months and they still work. Excellent value of course. They charge quickly.

Works really well in a tens unit I have. A charge lasts days vs hours using ni-cads. Rapid charging but not necessary. This purchase was for two units plus a dual USB charger cable. Very satisfied.

The batteries charge fast and work great!

First impression, these batteries are super light as they are actually 3.7v 1000 mAh which converts to a 9v around 400 mAh approx. These batteries will drain on their own faster than alkaline so advertising them for low draw devices is kind of misleading. I'm using this in a meter that measures square footage of buildings and area. This battery is perfect if you are constantly using your tool and need to recharge it, this will save you a ton.I don't recommend using it in long time rarely used temperature measuring tools or smoke detectors as you'll find yourself charging these all the time. In comparison alkaline 9v batteries are anywhere from 450-600 mAh.A word of warning because this is converting the voltage from 3.7 to 9v when it's ready to die, it'll just suddenly die. This is a normal behavior and not a defective battery.Overall I highly recommend these 9v batteries for high usage tools, and not for backup batteries for keeping clocks during power outages or backups for smoke detectors. I mean you can use it for smoke detectors just don't be surprise if they don't last nearly as long as your alkaline batteries you are replacing.

I would not recommend these batteries. One of them lasted just a single cycle before it completely stopped working. Only two come in the pack, which makes it a terrible value for the price. Unfortunately, I’m now past the return window and stuck with a dud.

Good quality product

I am using these in meters and other low draw devices. So far they are working great. Unfortunately the 1000mAh rating is misleading. That rating is at 3.7 volts. This means the battery shod deliver around 400mAh at 9 volts. For my uses this is not an issue but I find the advertising of 1000mAh inappropriate.One star deducted for misleading advertising.