Review on 5-Pack EBL 9V Rechargeable Lithium Ion Batteries With 600MAh Capacity And 5-Bay Charger For Smoke Alarm Detectors - 2A Input by Edward Mcnamara

I ordered three kits of these so I had plenty of rechargeables for our stage productions. No DOAs. All of them took an initial charge and held it. While in use in a 3.5W application, they all lasted over an hour which is what I needed. 600mAh batteries at 0.25A should be around 2 hours, but I haven't tested them that long yet.I noticed a lot of people reviewing with poor ratings due to "not working in my smoke detector" or "shows low battery in my multimeter." This is important to understand. These batteries are 9V format, but they are not 9v output. They put out between 7.5-8v as advertised. The Li-ion chemistry makes it nearly impossible to stuff 9v into the same size battery. If you put these in an appliance that is expecting 9v or more from an alkaline battery, it will detect the lower voltage and think you need to replace batteries, even though they may last just as long (or longer) than an alkaline.In my case, I purchased these for a project that needed between 9v and 36v (some LED lighting), so knowing that these batteries were lower voltage, I put two in series and I'm getting 7.6v across each individual battery for a total of 15.2v at the LEDs. Perfect for my application.Long story short, if you use them in something analog (a motorized toy for instance) they will be just fine. If you use one in a digital item (smoke detector, multimeter, or something with a digitally-monitored battery system) you might get a low battery indicator. For me, they're perfect.