Everyone has a theory about how to take care of rechargeable batteries ranging from neglect to pampering. In normal daily use, batteries are nearly completely discharged by the end of the day and recharged overnight.
Memory is prevented by significant discharge and full recharge on a regular basis.
If this is not your normal cycle, then you should schedule a full discharge once a week. Once a week, leave the radios on until the batteries are discharged. The radio should shut off, lose its display or give you a low battery warning. The battery should then be recharged immediately. Don't allow the battery to continue discharging and don't let them remain discharged for more than two days.