NITECORE New i4 battery Charger For Li-ion / IMR / Ni-MH/ Ni-Cd 18650 18350 16340 RCR123 14500 AA AAA D C w/ Ac and 12V DC (Car) power cords, EdisonBright BBX3 battery box, 2 X AA to D type batteries

I've been charging NiMH aaa and aa sizes and 18650 lithium an RCR123A batteries. It's a nice system and seems to work just fine. They do warn to charge aaa in pairs in slots 1,3 or 2,4 as the will charge a single aaa at too fast of a rate. Other than that warning, it's plug and play for any single battery. I would say it's not a super fast charger, but I think that also makes it safe. I think it indicates 1.5 watts charging rate per slot. So if you've got a 9 watt-hour 18650, it might take a while to go from zero to full. Quicker for smaller watt-hour batteries like an aa or aaa NiMH. There is a shutoff circuit but I'm not sure it's overly smart. It indicates it will shutoff if the circuit is active for 20 hours. It specifically says it is an "overtime prevention". I'm guessing it relies on a slow charge rate not to damage a battery if it overcharges for 20 hours. But it also says it automatically stops charging when complete. So I'm scratching my head a little bit wondering exactly how the protection works. I like the fact you can charge individual batteries and that it works for so many varieties of batteries. Very convenient single item to charge all of one's batteries. I am satisfied and I do recommend it. I recently charged a 18650 lithium and the charger circuitry did get a little warm, in the top of the unit (still well under 120F I estimate). The battery did not get warm. Not a concern, but one might want to make sure the device has some air circulation to it and is not resting on a blanket or something.

I received this product today and charged a set 26650 batteries. It was very fast but I didn't time it. The unit appears really well built and the intelligent features are great and easy to use. This is my third charger. One just wore out and also it had no intelligence or safety features. The other one worked only one time and I returned to Amazon. Hopefully this will last as I really like it.

If you are going to use a lot of batteries, and want to try rechargeables, you need a good smart charger! Do your research, this one does all my batteries, and the de-charger button brings some bad batteries back to life. It's worked very well, easy to use and good instructions for a very complicated subject. I don't get it all, but I've been able to recharge all my batteries. A very reasonable price too, don't waste your money on those chargers that come with cheap batteries, the kind that just plug into the way. This one tells you how the recharge is going and when it's complete. Bob likes it.

Amazingly good charger... it can restore batteries capacity to some degree but will not bring them back to full health. Such is impossible, but any improvement it provides is welcome... highly recommend.

The great: this works with about everything.The bad: it makes a small clicking sound when charging like a clock. It only lasted 3 years, then scrambled itself and nearly blew-up three batteries.

Bought this to replace my old one that broke after 10 years of use. This one is awesome. It also seems to have improved the life of the old batteries I had.

Worked fine for 1.5 years. Just two days ago, I came home and installed a battery to charge on it. About an hour later hear an audible pop from the back of the house. Wife is in panic mode as she can smell burning/burned plastic in the house. I begin to get concerned. Tested every socket and light switch in the house, checked the breaker panel for kicked breakers. Nothing. Until we get to the last room - the office. Smell is strong. I see out of the corner of my eye the charge LED lights on in 1:4 spaces, but not where the battery is that I put in. Well, there plus another empty space not being used is flashing green like it thinks there's a battery in it. It kicked the surge protector fuse (thank F$#@). If we had not been home and it was plugged straight into the wall, it would have burned my house down.I feel this should be warrantied, by Nitecore, at minimum, and perhaps even a recall issued. I'm not sure. There was no electrical outage or anything weird like that happening at the time, it was just being used to charge my Nitecore brand 18650's that I use almost every single day, and have so for many, many years.Moral of the story, use surge protectors.Also want to say that I LOVE Nitecore. The only problems I have every had is from their chargers. I've gone through several of them - mostly they just flat stop working out of the blue. I bought the HC50 headlamp like 9 years ago and it is seriously the best ever. I just buy headbands for it and batteries on occasion.I hope someone of importance reads this and does something about it. Otherwise, this would be a 6-star review.

Been using this for a year now and has never failed me yet, very simple, input the battery, 3 lights indicate a full charge, its plastic but seems well built. The best thing is that when it charges batteries, they never get hot and charges gently, and to a full charge. Example, my 18650 batteries would always test as 4.0 to 4.1 volts with other chargers, but with this charger, it tests 4.2 volts, totally full charge and meters the charge in a gentle safe way, while several other chargers charge full on and the batteries get warm to hot. When charging is complete, the charging stops, and the 3 lights indicate completion, 1 of my chargers doesn't stop, don't use it anymore. Use this to charge all kinds of rechargeable batteries, I love this charger!