As a rule they say that we must discharge these batteries atleast 3 times for better use .
Technically, NiMH batteries do not have a "memory effect", but strictly speaking neither do NiCds. However NiMH batteries can experience voltage depletion, also called voltage depression, similar to that of NiCd batteries, but the effect is normally less noticeable. To completely eliminate the possibility of NiMH batteries suffering any voltage depletion effect manufacturers recommend an OCCASIONAL, complete discharge of NiMH batteries followed by a full recharge. NiMH batteries can also be damaged by overcharge and improper storage (see the NiCd section immediately above this one). Most users of NiMH batteries don't have to be concerned with this voltage depletion effect. But if you use a device say a flashlight, radio, or digital camera for only a short time every day and then charge the batteries every night, you will need to let the NiMH (or NiCd) batteries run down occasionally.
Source: *www.greenbatteries.com/nibafa.html#NiMH memory
You can find good info about the batteries you purchased here. As it says above you only need to do an occasional discharge and like expert said you can discharge it by using any device until the battery charge gets depleted.
