Everything is fine, just the only thing you need to know is that the AA batteries it comes with have a very short lifespan. I use them for an Xbox controller – it doesn't even have time to notify you that it's about to run out and the device shuts off.

It got too hot, the batteries were burning
bad charging, it lights up green but the batteries are not ready

The Duracell CEF14 charger with 2 sets of AA/AAA Ni-MH batteries offers a combination of high-quality, fast and efficient charging, reliability, and flexibility. It is a smart investment for anyone looking to reduce waste and ensure that their devices are always powered. Charging is faster than the 4 hours mentioned on the packaging. It is also great that branded batteries are included in the package and the charger's design is extremely convenient, as it plugs directly into the power outlet without any cables.

I have it for a day and I have tried to charge 3 different sets of batteries and it works fine even with other brands of batteries, with different capacities. Once the light turns green, it is fully charged. If you accidentally put in non-rechargeable alkaline batteries, the red light does not even turn on and it does not charge them. In other words, it can recognize if you put in the wrong batteries.

Everything works fine. You can find batteries with more mah, but this package is very cost-effective!