SINCEHOLY 4pcs High Power 1.5V Rechargeable Lithium AA Batteries, 3600mWh Long Lasting Double A Li-ion Battery(with Charger 2 Bay)

these batteries are fantastic. They charge in a small amount of time. The performance is outstanding. I use them in the church wireless microphones. Have no power failures. I haven't had to recharge them for two week ends, and they still show 75-85 per cent. The charger is really easy to use.

First up is the matter of rated capacity. Note that these batteries are rated in mWh, not mAh like NiMH rechargeables. A typical 1900mAh NiMH is around 2280mWh. With these rated at 3600mWh, they should have significantly higher capacity, roughly equivalent to 2400mAh. Being lithium, they should also behave better at cold temperatures, and will also endure more charge cycles. As for actual tested capacity, the average across all four cells was 3160mWh, quite short of the 3600mWh rating. This is roughly equivalent to 2110mAh at 1.5V. I obtained this by charging the batteries until full, using the included charger. I then discharged them through an electronic load at 250mA, which is very low and should give a best case scenario as energy lost to heat will be minimized. The highest was 3228mWh, and lowest was 3104mWh. Unfortunately, the current delivering capability isn't quite there, either. I don't see a rating given, but was only able to get about 3.3A out of them before the overcurrent protection stepped in. NiMH cells can usually give 4A or 6A no problem. Indeed, when I tried these with my camera flashes (Godox TT350S, relatively small ones), they failed to prime and showed a low battery symbol. Disappointing, because that's one of the uses explicitly mentioned in the details. They'll work for a lot of other devices which don't demand as much peak current, though. Charging must be done with the unit included in the box. It feeds 5V to the battery, which steps it down internally. You can't stick these in an ordinary NiMH or lithium battery charger, nor can you put other types of batteries in this charger. That's a little bit of a bummer, but understandable. Thankfully, it instantly rejects NiCD/NiMH batteries instead of trying to charge them at 5V. On the plus side, USB-C charging is implemented correctly, with the charger having the proper 5.1k pulldown resistors to request power from a USB-C charger, even when using an e-marked cable. Its build quality is also great. These deliver the full 1.5V until they are depleted. Unfortunately, that means the battery meter on your device will read 100% until it suddenly shuts off. That's common amongst all of these rechargeable lithium AAs, though, since there's a step-down from ~3.7 going on inside. Overall, I'm still pretty happy for the price. They're still highly useful in most devices which eat through AAs, just be aware they won't deliver as much current as alkalines or NiMH rechargeables. Not many devices need that much, but it's worth checking first.

I use them for the TV remote, and they work well

Good item connect with u s b c for batterecharging

When they work they are awesome, but 2 bad batteries out of 16? Thats a 12.5% failure rate. Completely unacceptable. The worst part is that I received one bad one with the initial box and the other went bad after 2 months (you can see the red LED on the charger). And because I was using them on a door lock, the lock died completely and was unable to notify me that I had low power and the lock stopped working immediately. Now lets see how long before another one goes bad. These are really unreliable batteries. Looks elsewhere

This product is a set of four (4) AA-pattern Lithium-ion batteries. These batteries have the AA-pattern standard 1.5-volt power output so that they can be used with those devices that use standard disposable AA batteries. These batteries can be recharged 2000 times or more by using the included battery charger device. The user will need to supply power from an industry-standard USB-C power source such as that used with most current smart phones. The supplied charger can accept one or two batteries for charging and each battery is individually charged. Further, the charger can detect when a battery is defective or over-heated and report that condition to the user with the charger’s LED lights. These batteries have a capacity of 2,400mAh (or 3,600mWh) each, which is a substantial power capacity. Perhaps best of all, batteries that utilize the current Lithium-ion chemistry such as these, have a very low self-discharge rate so that once charged, the batteries will remain charged for a very long time whereas commonly used alkaline cells are constantly in a state of self-discharge. Additionally, Lithium-ion chemistry batteries have a constant voltage output until they are nearly discharged. This allows the device being powered to work properly until the battery must be recharged. No more dim and getting dimmer flashlights when using these batteries! These batteries have a built-in chip which controls the power output and provides protections for the use of the battery. The protections provided include: ○ Output Over-Current Protection ○ Input Over-Current Protection ○ Overcharge Voltage Protection ○ Overcharge Current Protection ○ Over-Discharge Voltage Protection ○ Over-Discharge Current Protection ○ Short-Circuit Protection ○ Temperature Protection When I received these batteries, I set about charging them. Charging took some time due to their large capacity but each one charged and when tested each one worked properly. I did note that the batteries did get warm while being charged. I am very happy with this product!

I had high hopes for these batteries. This is my fifth set of Li-ion AAs, fourth set of AAAs, and seventh purchase of 9Vs. Unfortunately, the 9V batteries were a complete disappointment, and the AAA versions were too expensive to be practical. I’m still searching for a battery manufacturer that fully lives up to its promises, but these come close. The batteries arrived in a well-designed, ornate cardboard box with a reusable plastic case—great for protecting and organizing them when not in use. The first thing I did was check the voltage straight out of the package. The readings were all over the place: 0.044V, 0.71V, 1.17V, and 1.1V. So, it was straight to the charger. I used a two-slot charger specifically designed for Li-ion batteries. It has two multi-function slots and a USB-C port for charging, but no cable or wall adapter was included (nor was one promised in the product listing). When I started charging the first two batteries, the indicator lights flashed red after just a few minutes. I reseated them, swapped the cable, and tried again—only to get the same red flashing lights. I repeated the process with the other two, and this time, one battery began charging properly while the other still flashed red. Switching to a high-speed 100W cable and a 45W wall adapter finally solved the issue. Both batteries began flashing green, indicating they were charging correctly. I tested the first pair again, and they also charged properly with the upgraded setup. In total, the second set of batteries took about 30 minutes to fully charge, while the first set took closer to an hour. Once fully charged, all four batteries measured above 1.37V. Initially, I was going to leave a negative review, but to be fair, the instructions didn’t specify any requirements for wattage or cable quality. And honestly—who actually reads battery instructions? Apparently, I do. To put them to the test, I used these in my drone controller. Normally, a set of four AAs lasts about 40 minutes when viewing in 4K, but with these, I got 1.2 hours and still had charge left. That’s a huge improvement. 1 caveat is the instructions,, there's a lot to read for a sub font below 1 Forget reading these on 2x you need around a 4 to see the wording clearly. Overall, these batteries perform well and come very close to their advertised capabilities. Just make sure you’re using a high-quality charger and cable. Your mileage may vary, but for me, these are keepers.

Ordered these to use in our biometric door lock for our back door and they are working perfectly, so well that when we get our new front door, I will be ordering a 2nd set for that lock as well. The price is very afforable for not having to purchase batteries for replacement, rather just recharge them and you're good to go!