KrataxUSB Rechargeable 9v Lithium Batteries 2 Pack 760mAh 9 Volt Li-ion Rechargeable Battery with 2H Quick Charge Cable, 1500 Cycles Long Lasting for Smoke Detectors, Microphones

These are super easy to recharge and hold a charge long time for our medical pain device.

These work great. For them for my husband as he plays guitar and needs runs through batteries like crazy. Haven't had any problems yet they're pretty awesome :)

Played my first three set gig with the Kratex powering my (as measured) 134 mA Tonex One. I also tested it at home and it was going strong after 4 hours of continuous operation of the Tonex. Seems to meet their spec at roughly 1.5x the watt-hours of a standard alkaline 9v battery.It also charges at a 10 watt rate which is 4x what the next nearest battery of this type I tried. When it is fully charged it completely stops taking any current from the USB power source. The battery seems to fully implement USB C orientation protocol, which others of this type do not.It does operate at a very slightly lower voltage than a fresh 9v alkaline, but well above what an alkaline would fall to inside its useful lifetime. This was implemented in the interest of being compatible with older 9v battery chargers, which I don't own and did not test. But what I did test was whether it could power any of my collection of guitar pedals, and it at that task PERFECT!

These 9Vs don't seem to want to take a charge. Disappointed because their AAs are just Amazxing!!!

Well built. Worked really good in my power hungry milwaukee scope. Ran it for an hour and still plenty of power left. Easy to charge just plug usb c cable in the side of the battery.

Yes, Great product.

At first glance, prior to using it, it seemed to be great. Something I particularly liked and something my husband even commented on, was how cool the charging cord is. It is one Cord with 4 ends to charge the batteries.When charging the batteries there is a little red light that will light up, and once it is charged the light will go away. I wished that the light would have turned GREEN to indicate that it was done charging, but the light simply disappears.These work just fine, however I gave it 3 stars as I noticed that for what we use it for it is not lasting as long as a regular 9 Volt Battery. I use these for our microphone, and normally one 9 Volt Battery can last about 1 month before we need to switch a new battery. However this one only lasted about 2 weeks of about 1.5 hr use. So it seems like it doesn't last as long as regular batteries. Maybe if you were to charge these after each use these would be great. I'm not sure. But I was just curious to see how long one charge could last with our normal use and it lasted about half the time as a regular 9Volt Battery. But I assume that if I were to recharge it after each use, I wouldn't have noticed the difference.Great little Batteries. Just wished they lasted longer for what I use them for.

I think it lasts longer than the regular battery and I love the fact that you plug right to the battery and not a base. It comes with a charging cable that you can charge several batteries at the same time