Review on TalentCell 9V Lithium Ion Battery: High Capacity 500MAh Rechargeable Li-Ion Polymer Battery With Micro USB Charging Port - 1-Pack For Ultimate Convenience by Chris Elam

First; I am suspicious of the mAh claim.It works well and holds a charge. I use my 9v powered multimeter quite frequently and got tired of looking for new batteries and borrowing them from smoke detectors. A terrible place to take them from when working with electronics but I had to do *something* to keep working.then I saw this. Now I never have to worry about scrounging around for batteries and it's easy to charge when I'm finished using it.