4x EBL USB Rechargeable 9V Volt Lithium Batteries 5400mWh + Micro Charging Cable

Charged quickly and easily. Will add more when I've used a few times, but first use good.

I enjoyed it charged within 2 hours and you fully know when it is fully charged and it has enough milliampras to go into smoke detector which I truly enjoyed

So far so good. All charged about the same time. Works well. Looking forward to long lasting battery life with many recharging's .

This is an amazing product. Just what I needed for replacing 9Volt batteries. I love the ability to be able to recharge and use over and over again.

man couldn't have came at a better time. Just in time to metal detect

I am going to be totally honest! I was not aware that lithium rechargeable 9v batteries only have a full charge of 8.2 -8.4v brand new, so if your device requires a full 9v these might not work! I am using these to replace alkaline 9v batteries in my driveway alarm sensors to try and extend battery life, replacement costs and to last longer! So far the lower voltage of 8.28v seems to be working! I won't know for a month or two if rechargeables are better, certainly hope so! I find that longevity depends on how often they alarm from traffic or false alarms from sun and wind, etc! If they work well, I should be able to swap them out and recharge many times!

one of the 4 batteries charge light never turned green but the voltage seemed fine .

Easy rechargeable, use in fire alarms and microphones

The item is listed as being a rechargeable 9V battery with one use for "Smoke Detectors/Fire Alarms", my intended use. I followed the instructions and charged the battery prior to placing it in my Smoke Detector. Within approximately 30 seconds after installing the battery, the Smoke Detector emitted one loud beep and repeated doing so every 30 seconds. This is the Smoke Detector notice that the battery needs to be changed. A second battery did the same thing. It turns out that the battery will only charge to a terminal voltage of 8.2V - 8.4V when fully charged. My Smoke Detectors will run on a new Alkaline 9V battery for approximately 1.5 years before they start screaming to have the battery replaced. I purchased another brand of 9V rechargeable battery and they did charge to a 9V terminal voltage and worked in my Smoke Detectors. I found on the EBL website after a long search where it stated, "The terminal voltage when fully charged will be 8.2V - 8.4V".

I bought 8 of these and they don't maintain voltage at all even when not used in the smoke detectors. Be prepared to recharge them every week or two. I'm not sure what the value is on these when they simply just don't work well at all.