EBL Rechargeable 9V Lithium Batteries, 5400mWh USB 9 Volt Li-ion Batteries Long-Lasting(2 Pack)

I purchased these to use in all of my smoke detectors in the house because I got tired of buying 9 volt batteries over and over again! And they work like a charm!I just hope I remember to get them when I move out of my apartment 🤣🤣🤣🤣

These 9V rechargeable batteries have made managing my Smart Locks so much simpler. I like that I don’t have to keep buying alkaline batteries, and being able to charge them directly with a USB-C cable is convenient.I haven’t needed to recharge them since installing, and the lock is still working great. It’s reassuring to have a reliable power source for something I depend on daily.

First, about the "5400mWh". Oddly, this battery is measured in miliwatts... This means that if converted from watts to amperes (5400/9=600). So these batteries are actually 600mAh. While not a spectacular capacity, It is a high capacity still comparing to disposables or NiMh batteries which are more of a 200mAh. So the value for the money is very good. The integrated charger is a very convenient feature and works well. Also, the weight is a lot less than conventional batteries. I am giving this product 4 stars because while the packaging is labeled with a picture of electric guitar, these batteries do not work in my particular application. So there is a chance that these batteries will work great in you instrument, however, there is also a chance that they will not.Now about my specific application. I bought these to put in my Peavey Grind Bass Guitar modified with VFL4 active pickups (those who cares, would know). Returning because of the hissing noise the guitar outputs while with these batteries. Comparing to regular disposable batteries, the same bass has no obvious hissing noise at all, unfortunately with these, fully charged, EBL Orange/Black 5400mWh ( with integrated charger), the noise is unacceptable.The seller was gracious enough, as a replacement, to offer me similar EBL batteries that are white/blue and labeled as 600mAh. These batteries work exceptionally, with no noise, and have the same capacity and weight. One difference is that the replacement batteries do not have an integrated charger, but rather come with a conventional desktop charger. Perhaps the integrated charger causes the noise. So in case if the Orange/Black batteries with the integrated charger, do not work for you, you can always count on EBL White/Blue ones. I have left the 5 star review on EBL White/Blue batteries page.

Charges quickly, I use them musical equipment lasts long

Thay work great for smoke Detors

Works as expected. Takes just a little longer to charge. Packaged very well.Would buy again from this seller

It looks like these have been redesigned, although I didn't think to take internal pictures the ones I got used 1 Lithium cell with a boost-regulator on the output vs some older reviews that found 2 cells in series.The good: inexpensive, easily recharged, sits at 9.0V until shuts off dead.The bad: Voltage says right at 9V until the very end, then it "shuts off" abruptly, and sometimes turns off/on repeatedly. This means devices can't tell the battery is getting low before it totally dies without warning. Also doesn't handle high draw particularly well (e.g. for label-makers) voltage falls off quickly over 120mA. Also has a fairly high oscillation on the output regulation, and lasted less time than some other batteries tried.Based on my tests, these would be quite dangerous in anything life-safety (e.g. smoke/CO alarms), nor would it work in higher draw items like a label maker. It would be okay in non-critical applications like a low-power toy, multi-meter, or stud finder. There is some noise in the output signal but its not that severe - this could be a consideration in sensitive applications though like wireless microphones.

As the pictures show, they do not load test 5400 mWh.I followed their instructions. (they have added >60 years old is approved to use):Charged until light changed from red to green (instructions said blue).Discharged @ 0.1 amp. (100 milliamp) to 7.2v; load test resulted in, practically, identical results. 2436mWh. Tester ended test, not battery.Another 2 cycles.This time I used a USB multimeter to watch the charge. The battery will trickle after the light shows a full charge. I unplugged them when the the light changed.The multimeter shows it taking ~5500mWh of charge, but it does not come out.I even tried a 0.01amp pull that lasted overnight and while it did end when the battery shut off (instead of the load tester getting below 7.2v) 3236mWh is the best I've gotten; that was at 0.1 until 7.2v and then 0.05 for just a few more mWh.They are consistent and they have undervote protection.