At 0727hr a 14m launch reported via cellphone that it had flat batteries and needed a jump start or new batteries. The launch had overnighted at Sulphur Bay Whale Island. In the morning it was found that its batteries had gone flat. An all stations alert was made and a good samaritan assisted. It was found that new batteries were required. Whakatane Rescue was tasked to assist and was launched at 0839 with two new batteries for the launch. At 0911 the new batteries had been installed and the launch was again operational.  At 0930 Whakatane Rescue was safely back in port.