Yacht Controller transceiver remotes are fitted with wireless charging. With earlier remotes when the low battery indicator LED flashes, the transmitter batteries must be replaced within two / three hours of operation. It is a good idea to always keep three 1.5 V AAA (LR06) high quality alkaline batteries in the boat or change them at least once a year at a memorable time. Do not install rechargeable cells. Follow the user manual instructions to replace the batteries when required.