A 5m yellow boat reported via cell phone that it was at the Raurimu Islands and needed assistance because of a a flat battery. Sea conditions were good with 9-12kt wind from NNW and calm seas. An all stations call was made and a good samaritan commercial boat offered to assist.  The flat battery was fixed and the boat was able to make its way back to Whakatane under its own steam. However, the good samaritan later had problems and requested a tow across the Thornton bar. At 1536hr the good samaritan reported it was safely across the Thornton Bar and at 1541hr the yellow boat was safely back in the Whakatane River.  Many thanks to the good samaritan.