Panasonic K-KJ17M3A4BA Advanced Individual Cell Battery Charger Pack with 4 AAA eneloop 2100 Cycle Rechargeable Batteries

This is an excellent NiMH battery charger. You can use it with any brand of NiMH battery, and because it's a smart charger it will always charge the battery perfectly. There is a green light under each battery while charging, and the light turns off when charging is complete. The light will blink for a few seconds when the charge is checking the status of the battery, and the blinking will continue if there is a problem. "Smart" chargers constantly measure the condition of the battery to determine if it's time to stop charging. There are "dumb" chargers out there that operate based on time, so they always over-charge the battery, resulting in the battery converting the excess charge to heat and damaging itself. Avoid dumb chargers. With NiMH batteries, chargers that are too fast or too slow will undercharge or overcharge the battery, while normal-speed chargers will charge the battery perfectly. This charger is a normal-speed charger. I think the speed of this charger is acceptable, as you can leave it on overnight to charge and they will be ready in the morning. However, if charge speed is important to you, don't feel bad about buying the Panasonic fast charger, because batteries are meant to be used and the batteries will still last a long time even if fast charged. Note that fast charging also makes the batteries hotter, especially towards the end of the charge cycle, and heat can damage batteries slightly (again, nothing to worry about if fast charging is important to you, just know that your batteries will not achieve the 2100 cycles if fast-charged every time). This normal-speed charger only makes the batteries slightly warm, as expected. Because this charger charges at what I consider the ideal charging speed for NiMH, I believe it is the best charger available from Panasonic. As long as you keep a supply of already-charged eneloop batteries, you won't mind waiting for batteries to charge because you can just use your already-charged batteries. White-label eneloop batteries have such low self-discharge that keeping a supply in storage won't be a problem; they will always be ready to use! For the black-label eneloop pro batteries, which have a higher self-discharge, you should probably recharge them every 1 or 2 years if you want them to be ready-to-use from storage. Use rechargeable batteries for ALL your devices! You might find a picky device that doesn't like the 1.2v to 1.4v voltage of an eneloop NiMH battery; in that case, I recommend searching Amazon for the 1.5v rechargeable lithium batteries such as TENAVOLTS or other brands. Those rechargeable lithium batteries provide a constant 1.5v, filling the gap for the few devices that an eneloop battery can't work in. That way, you will have completely switched over to rechargeable batteries! Read more

I'm an eneloop evangelist these days because they work so well in AA and AAA flashlights, kids toys, remotes, and countless other devices around the home. The initial upfront cost seems a little steep at first, but when you start using them and realize how quickly they pay for themselves, you are going to wish you had more for everything in the home and that's how this all begins. Take a chance on them. You won't regret spending extra for the high quality eneloops. The other brands simply cannot compare. Read more

I absolutely love these rechargeable batteries! I use them everyday day and they last forever before having to recharge them, will be buying more in the future that’s for sure. Read more

This is my second purchase of Panasonic Eneloop rechargeable batteries. I have the AA and AAA sizes. I use the AA for a pocket flashlight I keep in the car, as I didn't want Lithium due to excessive heat in the car in the summer. They've been great, and I just recharge them every few months if not using the light, or shortly after if using it. I bought these for remotes as I'm tired of buying alkaline for them. Read more

I bought a 2-pack with chargers, one pack of AA and one pack of AAA. The AA are great, they work and charge as expected and sit securely in the charger. The AAA...I don't know what the thought process was here. The AAA batteries don't stay in the charger whether the charger is plugged in facing up or down. The AAA batteries barely sit in, seemingly lightly magnetized in their tiny slot so that the charger can also be used with AA batteries. The only way the AAA batteries will stay in the charger is if the charger is plugged into an outlet on a horizontal surface; using a vertical wall outlet results in the batteries immediately tumbling out. Honestly what was the thought process here? Couldn't they have just made a smaller charger intended for only AAA batteries? I don't have any horizontal outlets, rendering the charger useless. I'm keeping the AA pack but returning the AAA pack. Read more

My go-to combo of charger and batteries. Does not overheat batteries during charging. Read more

It was good with LED light letting me know the charging status. I have tried with the batteries attached. It was great! The charging speed is good since I am not in a hurry. Recommend! Read more

These are great. They have a long battery life, and they have saved me money in the longrun. I see no reason to buy disposable batteries anymore. Double thumbs up. Read more