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

Though I can't attest to the durability of this universal NiCad/NiMH battery charger, I can say that it works as expected and seems to be well built. Some reviewers have complained about difficulty reading the illuminated blue readout window, but I haven't found the limited viewing angle to be a problem. Otherwise, the spring-loaded contact arms are sturdy, and it's easy to load and unload batteries. The machine automatically detects the chemical composition of each battery and charges accordingly. Because I use NiMH batteries, I haven't tried the "Discharge" feature, which I assume is useful for NiCad cells that get lazy and don't hold a full charge if you don't discharge them every few months, or as needs warrant. My only gripe at present -- and it's a minor one -- is the lack of rubber or plastic feet on the machine, preventing it from scratching a wood countertop. I fixed the problem by attaching four self-adhesive pads available at the Home Depot, but I think Tenergy should include these. Otherwise, I give this charger two thumbs up and expect it to deliver many years of faithful service...

Rechargeable batteries are the way to go. Both for the environment and your wallet. Saved me tons of money & I keep my extra ones charged and ready. No waiting. This charger does all sizes so no need for multiple chargers. Silent charging. Great quality batteries.

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.

Reviewing Tenergy T9688 (4 slot D-C-AA-AAA and does AAAA as well) Purchased 08 Feb 2023 All 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.

Saves so much money with being able to recharge these batteries.... we love ours so bought my son this for grandkids toys and batteries last years. Recommend highly....

The C and especially D, batteries become very hot after charging. Took a couple of hours to cool down enough to store or use; even after removing them from the set, which wasn't easy with them being hot. Is that normal for charging C and D batteries? Is that a safety issue? The charger itself became warm but not hot. Do not leave charger unattended, especially as C, D and 9V batteries take several hours to charge; 7 or more. Unplug charger between uses. Otherwise, very easy to use charger. That it charges, AA, AAA, C, D and 9V, is a plus. Very nice looking. The font telling you if your batteries are still charging or done or bad, is very tiny; hard to read. It came with a pack of its own brand of each type of batteries it charges. Don't yet know long the battery life is or how long they work between charges but it has made a long mini light string nice and bright, when regular non-charging batteries made them barely glow.

Works great and takes up little space.

Don't waste your money

Please beware that this comes with a US style plug so not suitable for uk. The photo does show it but it is not obvious.