EBLRechargeable 9V Batteries, 5400mWh USB 9V Lithium Rechargeable Battery (9V Batteries- 4 Pack)

I decided to test the performance of this battery by first depleting it completely, then recharging it while measuring the voltage at scheduled intervals. (See attached photo). Note that my multimeter gives the depleted voltage in millivolts so it’s actually reading 0.0002V. But after just five minutes on the charger, it already came back to 6.97V. From there the voltage inched it’s way back up, but it really didn’t change substantially. It’s not perfectly constant, but this battery gives a very nice, steady performance over its life and it dies abruptly once it’s been depleted.I also wanted to test the longevity of this battery compared to some popular alternatives. I tested this against a Duracell 9V alkaline battery and Energizer’s Ultimate Lithium 9V battery by putting all 3 in a 9V flashlight to see how each one performs under a constant drain.- Duracell Alkaline: Given the way an alkaline battery gradually diminishes, and my flashlight becomes gradually dimmer as it dies, it wasn’t easy to discern a reasonable cutoff voltage where I called it dead. So I decided to measure how long it takes to drain down to 7V, because that’s about where most of my 9V devices fizzle out anyway. In my flashlight, this took approximately 12 1/2 hours.- Energizer Ultimate Lithium: This one also held a fairly steady voltage. Even now it shows over 7V on no load, but it can’t draw any meaningful current anymore. I got about 18 1/2 hours of use out of it. Not bad, but disappointing considering the high price.- EBL 9V Lithium: By far this was the most straightforward to measure. It brightly lit my flashlight, and died abruptly at 13 1/2 hours.So this ran about 8% longer than the Duracell did. Energizer Ultimate Lithium ran about 37% longer, but it’s expensive and non-rechargeable. As of this writing, this product is listed at $6.25 per battery. The Duracell and Energizer are listed here on Amazon at $3.50 and $7.19, respectively. At these prices/ lifespans this rechargeable battery pays for itself in about 1.65 charge cycles compared to the Duracell, and 1.2 charge cycles compared to the Energizer.I recognize that this has been less of a traditional review, and more of a data presentation, so I thought I should add here that I’m very happy with these. They performed very well over a charge cycle, and the lifespan exceeded the alkalines that I used. Plus it costs next to nothing to recharge them, so it’s a great money saver. The USB recharge is fast and convenient. This is very innovative, and I’m rapidly phasing out my old disposable batteries.Edit: 11/10/2022I bought these a little over 2 years ago and they’re still going strong. As I noted in my original review, these have a little over 8V on a full charge, then they discharge to about 7 volts before they die. This is fine for all of my applications (mostly tools) but if you have a more sensitive device, I would recommend Energizer’s NIMH rechargeable battery. The downside is that they have less energy density and you have to buy a special charger for them, losing the convenience of this USB charging system. (The Energizer and EBL chargers have both worked well for me). But if you do need something that’s a little higher voltage, the NIMH maintains 8.4V all the way to the very end of its charge cycle.

fantastic product, they feel a bit cheap but they last very long and charge quickly. they have saved my a ton of money and are literally just the same as normal 12v batteries but rechargeable

UPDATE: After having issues with my last order of 9V lithiums and documenting them, EBL reached out to me (not the other way around!) and immediately replaced it. I now have good working smoke detectors. I'm VERY happy with the exceptional service and it has changed my views 180 degrees on the company.LAST REVIEWI bought a bunch of these for the numerous smoke detectors in my 12 room B&B. For years, I have been using Alkalines and I've been slowly switching to lithium rechargeables. I had good luck with other Lithium rechargeables but tried these EBL as these are 1/2 the price. I got these in May and charged them up. It's now the middle of July (technically less than 2 months later) and two of my smoke detectors are beeping - signifying the need for change of batteries. I'm not happy with the really bad performance. My other lithiums and the alkalines lasts AT LEAST a year but the EBL is only 2 months. I will recharge again and see how these fare. If it improves, I'll update this review.

These are claimed at 5400mW/hr capacity which translates to about 700mA/hr so should be fine for most low power applications requiring limited attention over long periods. Mine actually have a fully charged terminal voltage of 9.16v which is very good for Lithium Iron. They also come with a nifty built in mini USB port for use with ubiquitous standard USB wall chargers.There is however a problem. The internal switching voltage inverter which creates the >9v output and allows this simple recharge feature generates RF interference. This means it can interfere with radio receivers nearby and can create audible noise in applications such as wireless speakers, portable music players and guitar pedals.I bought these for my guitar pedals but the generated noise made some of them useless. However with a terminal voltage of 9.16v they should work fine in flashlights, smoke detectors etc and that is what I'll now use them for instead.UPDATE:I was puzzled by why some of my pedals had interference while other did not and so I did some testing. The first thing I noticed was that the length of lead between the battery and the pedal had quite an effect. The longer the lead the quieter the pedal became. Next I hooked up a scope and noticed that at no load the internal regulator was still generating about 50mV of ripple at roughly 70Hz. (This thing is always awake!). The frequency of the ripple increased with load until it became roughly 200KHz under a 30mA load. So this explained why a longer lead which has more inductance and hence more filtering reduced the effect of the ripple. So I increased the supply rail decoupling and inserted an RF choke between the battery and the circuitry inside the problem pedals and "hey presto" no more noise!So the noise issue is dependent upon the amount of supply rail filtering within each individual pedal. Some designs are just more susceptible that others. Having added an RF choke to some pedals the batteries are now quite useable.I like the terminal voltage being >9v, the capacity being about 700mA/h and the nifty simple recharge feature. Also a minor mod to the pedals means I can use them for what I originally purchased them for so for me I've raised the rating to 4 stars. (However I won't be using these in any AM radios!!)

I have not used them yet, but love they recharge easy, and looks like they will be wonderful.

Been using store bought 9v for a pin pointer for metal detecting. Most don't last long.This lasted a month. Although I didn't count the hours like I should have.At least 40 hours approximately. I'll do an update in a few months with more accurate hours.Easy to re-charge. Great battery.