The best! I also got the matching batteries and everything is great! I've saved money on the kids' remote-controlled toys and they play all day (now whether I'm happy with the buzz buzz all day is another matter :s ) time will tell how well everything will turn out but surely (I hope) I won't need to buy batteries again for years heheee

Update 16/5/2025: So far so good! Almost all the batteries in our house are now Varta rechargeable, still going strong. We also charge another brand of the same type and they are perfectly fine, any toy that takes a battery the child (being older) removes them and charges them on their own, waits, and puts them back to play. It's been a lifesaver! I highly recommend it! It's the best for all homes because we are also doing good for the environment. Remote controls, clocks, even radios, I haven't changed batteries for months. The only thing you need to be careful about is to get the device you like, the right batteries, and when charging is done, make sure the device is not getting dusty. We are now also looking into a solar charger for even more savings! Happy shopping :D

I charge around 20 AA batteries per day during Christmas. Some are black Panasonic Eneloop (2550 & 2500 mAh), some are white Panasonic Eneloop (2000 mAh), and some are Energizer (1300 mAh). (Yes, the black Eneloop ones are the best). It recognizes and charges all of them properly. It charges the 2550 mAh ones in 5-6 hours and the others proportionally faster (e.g. Energizer in half the time). When charging, the temperature of the batteries slightly increases, less than 10 degrees compared to the surrounding area, and the temperature of the charger is even lower, so I confidently leave it to charge overnight if needed. The charger seems to be powerful enough not to reduce its performance when charging multiple batteries simultaneously.
Although I have several AAA batteries, I haven't had the chance to charge any with this charger yet, so I don't have an opinion on the temperature they can handle or their charging time. I don't suspect anything negative, but if I am unpleasantly surprised, I will come back and update.
The charger is quite sturdy and doesn't take up much space. Its plastic parts don't move or deform, and the electrode contacts stay in place without any fear of them dissolving. Considering the cost of batteries, its price is quite good.
Advice to buyers: From the moment you buy a charger, the number of batteries only increases, so don't get one with fewer slots, or you'll end up buying a larger one in the future. I bought a charger from the supermarket on sale with the batteries (it was a bargain - thankfully it didn't set my house on fire), a four-slot one that I thought would be enough for my future needs, and now this one. If only I had known about it earlier, I would have bought this one from the beginning, I would have saved money.