Tenergy Smart Battery Charger for NIMH/NICD AA/AAA/C/D/9V Batteries, LCD Universal Rechargeable Battery Charger with Automatic Charge/Discharge Function & 5V USB Port for Digital Devices

The only problem that I could find with my Tenergy Super Universal Battery Charger is that it is too small. It is so easy to use and does such a great job charging my Tenergy batteries that I wish I could run more batteries for recharge at a time. I like the "discharge" feature as it allows your batteries to go through a complete discharge cycle which means you will have a smaller charge memory thereby allowing to charge and use a greater % of the battery. Its a well thought of product that does what they say it does every time , quickly, safely and with the ability to monitor the charge status. I recommend this product for value, performance and ease of operation. The price of Lithium batteries in going through the roof so here is your solution.

Charges good. Leta you know when they are fully charged. Also blinks at battery notification and says bad when battery isn't any good.

Reviewing Tenergy T9688 (4 slot D-C-AA-AAA and does AAAA as well)Purchased 08 Feb 2023All slots hold officially supported battery sizes tightly. (I have also used it for my tiny quad-A batteries and they work also.)I probably should give it 5 stars but sometimes I think people tend not to believe a review if 5 stars are awarded by a user.Charge time is moderate which is just what Tenergy advertises and it's just what I desire because the batteries last longer when gently charged. The discharge/recharge cycle works fine, too. I have no complaints. It's rock solid just like my other Tenergy charger.I also have a Tenergy TN162 8-slot AA charger since Juy 2021. It works fine all this time. No problems.The 4 slot T9688 has a 500 milliamp USB port. It's not worth much because practicalliy nothing functions on that little bit of power these days. The USB port only works when the charger is not charging batteries. I have a low draw USB lamp that uses 100 milliamperes. I plugged it into the USB port just for fun. The light plugged into the USB port comes on. If you then charge batteries, the light goes off...until the battery charging process finishes then the USB port is automatically re-energized and my lamp comes on again. So, the USB port could be used to light a lamp to let you know it's done charging. Or, maybe Arduino or Raspberry Pi users would want to use that port to trigger something fun when the battery charge process is done--like send an emaill or activate a buzzer?I don't know what else to say. The Tenergy chargers just do what they are supposed to do and they feel substantially weighted like high-quality materials probably comprise the devices. I plan to get another 4-slot Tenergy so I'll have 2 of the 4-slot models because my aged Vanson BC1HU 4-slot chargers are getting very old and smelling of phenolic overheat...so the young strong Tenergy chargers are ready to step in and take over and keep me powered up. Thank you, Tenergy.

As compared to my harbor freight charger, these tell me how full the battery is before it starts charging, and supposedly if the battery is bad. It charges far faster than the harbor freight model, at about 75% of the size, and it's a lot lighter. Even reads "charging" or "full" in addition to showing you how far into charging they are. Others have reported the batteries didn't charge completely, so maybe I'll be back to edit my review. Someone else said they had a problem after 6 months, and showed a corroded connector. I'd really like to know more about where they charged those batteries. Like, did it live in a bathroom that got humid, or in a garage? Not that it should matter, but corrosion on a connector is unusual, and I'm not certain that's the fault of the brand.

First one lasted 5 years. Got another one right away. Will buy again