For the occasional users of EURO-WAVE the cheapest solution is to use good quality alkaline cells such as Duracell. For regular users or indeed business users we strongly suggest the option of the CNB1 battery pack. Using Ni-MH cells this battery pack from one charge will giveyou an average duty cycle of 9 hours based on 5% transmit time, 5% receive time and 90% standby. (Knownas 5/5/90 duty cycle) Unlike Ni-Cad's, Ni-MH cells are not so prone to the dreaded memory effect.