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

Several things I like about Ni-ZN rechargeable batteries.One is they are the same physical size as regular alkaline batteries so they fit in your device. Many rechargeable AA batteries are slightly larger than standard AA batteries and won't fit in the battery holder or slot provided.Full disclosure: these EBL Ni-ZN rechargeable AA batteries if you got a micrometer and took a very precise measurement you show that they are a hair larger in diameter, but the difference is so slight it's not noticeable. They slid right into the compartment for me where other rechargeables would not go in at all.Second is they are 1.8v when fully charged and drop off to a nominal voltage of 1.65v.This compares to most standard and rechargeables that are rated at 1.5v or 1.2vAnd they maintain that higher voltage for a longer period of usage before dropping off. For example a standard alkaline will be 1.5v when first used, but will very quickly drop off to 1.2vSo what all this means in simple terms is these batteries are going to add a little 'boost' to your device. Your flashlight will be a little bit brighter, and for a longer period of time. This is referred to as 'overclocking' your device. The slight increase of voltage will not harm the circuitry unless perhaps you have a delicate device that has strict requirements.Ni-ZN batteries will last on average 50 cycles before they start to show any sign of self-discharging. They will still continue to work fine, this just means they will start to discharge on their own which is a common issue with rechargeables of various types.They are more environmentally friendly than most other batteries, although they still should be disposed of in a responsible manner.And they are reasonably priced considering the higher voltage rating and decreased drop off.BE SURE TO ONLY USE A CHARGER INTENDED FOR Ni-ZN BATTERIES !!!!And I highly recommend getting a wall charger adapter for the USB cable that comes with this particular brand. BE SURE IT'S RATED AT 5V / 2A (typical of most modern cell phone chargers)This will recharge the batteries MUCH faster than using the USB port on your computer, which takes FOR EVER! My only complaint actually is that I think the seller should include this adapter with the order, even if offered as an option.

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.