EBL 8 Pack Rechargeable AA Batteries Ni-Zn 3000mWh with 8 Bay Ni-Zn Battery Charger - 1.6V Double A Battery High Performence and AA AAA Charger

TL;DR: I would buy these again based on my experience.I purchased these in early Nov 2023 and have been using them in a couple of situations. I have had no issues with any of the cells not charging or the charger.First Use Case: CO/Smoke Alarm - this is my primary use case. I have a ceiling mounted CO/Smoke combo alarm and instead of being like all other smoke alarms, it uses AA batteries. But, it's picky. It won't take NiMH because the voltage is too low compared to alkaline (1.2V vs 1.5V). It immediately starts chirping for low battery. Next, I tried some AA lithium rechargeables (1.5V, like alkaline) and they were good for about 3 weeks. Then, the chirping started. So, I swapped in these since they run a nominal higher voltage (1.6V vs 1.5V of alkaline) and they have worked well. I first installed them on Nov 8 and they lasted until Feb 8 before a battery chirp occurred (this timeframe included one 8 hour power outage). Since Feb 8, they have been running a second round without any issue.Second Use Case: Roku remote control - I had used NiMHs in the remote for a while and they worked well. I decided to try these Ni-Zn ones since they have a higher voltage. These seem to last for a good while in a Roku remote. I haven't been keeping track of how often that replacement is needed, but that's highly dependent on usage. I believe they have been lasting about 2-3 months before needing replacement, which I think is a little better than the NiMHs were doing. The first time, I did get a low battery warning on the screen. The second time, I didn't see a notification, but I wasn't the one using it when it stopped working.I would buy these again based on my experience. They have reduced my usage of AAs for this smoke alarm and remote control. I hope they continue to function well, although I do expect them to degrade over time, like all rechargeables do. Do your research on Ni-Zn discharge curves. These may not behave like you expect/want given your device type.

I was excited to see a new, non-explosive, less toxic battery chemistry appear that seemed to have steady voltage performance like lithium at nearly NiMH prices. I bought several dozen, charged them to full, and put them in our automatic pet feeders. They worked fine and the motor even seemed slightly stronger. It looked like they worked well, so I put even more of these batteries in my cart to use in all our remote controls among other things. I left them there to purchase when I placed my next order.Some days later the lights on the feeders started blinking red which meant "time to change the batteries," so gathering all of them, I started snapping each one into the charger. During this process, the charger light indicated that eight or nine out of the pile of batteries were now bad. It refused to charge those batteries. My original excitement disappeared as I looked at the substantial pile of "bad" batteries. I was stunned to see one out of four fail after one use. While the "good" batteries were charging, I thankfully remembered to remove the additional batteries from my cart in case my wife placed the order. Then, I pondered what the problem could be.I'm the guy who always asks, "Why?" If you're like that too, keep reading to get the details on why.For everyone else, here is my recommendation: Don't buy these batteries until the charging kinks are worked out.So, after thinking about it, I recalled using four EBL (same brand) universal smart chargers to charge a bunch of LiFePo4 batteries. Their charger could sense every other type of battery, but you had to tell it when you were charging LiFePo4 batteries because they operate at a lower nominal voltage. (3.2 vs 3.7) When you set it for LiFePo4, it would charge the batteries at the correct voltage. Once the batteries reached the proper maximum voltage for LiFePo4, the charger would automatically switch from LiFePo4 charge mode into a "maintain full charge" mode. We noticed the runtime of our batteries seemed to get noticeably shorter each time they were charged. Using a voltmeter, I verified the LiFePo4 charge mode was charging to the correct voltage, but found that the "maintain full charge" mode was switching to the higher voltage of normal lithium batteries. This meant the EBL universal charger would slowly overcharge the already full (@3.7v) batteries to 4.2V. So it was damaging the batteries each time they were recharged if they were left in the charger. To get around this flaw, we had to constantly check the charge indicator and remove the batteries A.S.A.P. once they reached full charge. Since the problem was the charger when using those batteries, I wondered if the charger for these new batteries was programmed slightly wrong, too.It seems like these batteries can run down to a lower level than lithium without being damaged. Unfortunately, their battery charger expects the batteries to have a minimum charge that's higher than what the batteries can handle. Because the voltage it finds is lower than expected, the charger thinks the batteries have failed. That was my theory. Now, I wanted to verify it.WARNING! What I did to test my theory is a very dangerous thing to do, even using LiFePo4 batteries, which are less prone to explosion and catching fire. So, just to be clear I emphatically want to say nobody should ever do this! Ever!Anyway, to test my idea, I zapped a couple of these "failed" batteries by briefly touching (<2 seconds - several times with a 15-second cool down between zaps) the contacts of these 1.6V batteries with the full 3.7V output from a fully charged LiFePo4 3.2V battery.Doing this a few times on each raised the voltage of these batteries by about 0.2 volts, which was enough for the charger to recognize the batteries as "good" again. This worked on all the batteries that were supposedly bad. The charger recognized them as normal and successfully charged them.At first, I figured I could just do that before each charge to work around this problem. However, that approach took more time than I wanted to spend on this. Plus, I didn't buy these because I was looking for a part-time job manually (and dangerously) boosting batteries to the level the charger expects. So, I'll be buying something different - probably lithium. I still have hope for this battery chemistry to replace NiMH in flashes, remotes, and other things at some point, but until they work out a proper charger circuit that is better matched to the unusual behavior of the batteries, I can't recommend them to anyone.Bottom Line: At least for now, I suggest passing on these. I gave them 1 star because of the high "failure rate" indicated by the charger. Buyer beware.

The major advantage to these batteries is They have a higher initial voltage vs NiMh and even regular alkaline batteries. I bought this so I could put the batteries in toy RC cars. It turned a slow $11 RC car into a zany crashmeister with more power than what they intended and it didn’t even break it. I put it in another larger RC car and it certainly gave it way more power. Is this recommended by the manufacturer? Probably not but if my $11 car burns out, I have already got my moneys worth.I also put these into a decent headlamp I use outside in the dark. It was super bright and worked great.Just keep in mind their are issues with these batteries (supposedly) in terms of longevity and I knew that going into it. I have used them for probably 20 charge cycles over the last 2 months. No issues so far. I charge them immediately after use, so they might help. Not sure.It is hard to buy more of these batteries since no one makes them anymore (last I heard). But hey, I’m riding the end of the wave and when it’s over I’ll probably switch to lithium rechargeables. Those have a 1.5 initial voltage, so that’s pretty good. But I love the 1.6 these NiZn batteries provide.Charging is on par with other AA recharging systems out there. The batteries don’t even get hot when they are charging except 1 time Inhad one battery that kept charging and charging and getting hotte. So I took it off the charger for a while and then back on and then the charger recognized it was full. Usually the charger always recognizes the full ones, gives a free light, and stop charging that battery. Not sure why it didn’t that time.Anyway, if you want some obsolete batteries to make your stuff overpowered, these are worth a try.