It is a slow charger, which is a quality or a defect is as well-but read the following

The advantage of this charger is that unlike many others, he charged rechargeable batteries in pairs but individually, battery by battery. We can recharge a battery or 3 batteries for example. The odd numbers are sometimes useful in many objects nowadays.

The second advantage is that load SLOWLY. which is to increase the life of the NiMH battery currents that usually appreciate a charge called "1 / 10C" ie a load with a current whose numerical value in amperes is the tenth of the digital value the capacity in ampere-hours.
This provides an ideal time to load in 10 hours for NiMH batteries.

So a standard NiMH battery AA 2000mAh about should ideally be charged at 200mA or less to avoid damaging the battery. This is the case of the charger.

Note about chargers called "fast":

10 hours load (overnight) it seems to many long and can displease. So and only for batteries that support may be preferred another charger which delivers more than milliamps, which is called a quick charger.
BUT attention to a NiMH battery that supports fast charging is damaged if it receives an overload during a fast charge !!!.
This is generally not the case with a slow load of 1 / 10C

If you still prefer a quick charger, then also try to find one that allows individual load, battery battery, as they are more rare and it suits well the batteries sellers:

If a quick charger loads only in pairs or by 4 rechargeable batteries, it probably spoil the most charged batteries pairs you put in charge and they will then receive a fast charge mode overload,
and then you fall into the trap of planned obsolescence, or the charger detects a voltage variation of the first battery charge and will then stop following batteries that are not yet fully charged.
So good fast charger typically involves individual battery charger for battery.

Consider also if your already have a charger that charges in pairs or four to charge batteries of the same capacity. This will prevent damage to your batteries too quickly (and damaging nature thereafter ;-) See above.

Conclusion, this charger is a small and useful charger if you learn to use it well !!!