§  80.915   Main power supply.

   (a) There must be readily available for use under normal load
   conditions a main power supply sufficient to simultaneously energize
   the radiotelephone transmitter at its required antenna power, and the
   required receiver. Under this load condition the potential of the main
   power supply at the power input terminals of the radiotelephone
   installation must not deviate from its rated potential by more than 10
   percent on vessels completed on or after March 1, 1957, nor by more
   than 15 percent on vessels completed before that date.

   (b) When the main power supply consists of batteries, they must be
   installed as high above the bilge as practicable, secured against
   shifting with motion of the vessel, and accessible with not less than
   26 cm (10 in.) head room.

   (c) Means must be provided for adequately charging any batteries used
   as a main power supply. There must be a device which gives a continuous
   indication of the rate and polarity of the charging current during
   charging.

   [ 51 FR 31213 , Sept. 2, 1986, as amended at  58 FR 44953 , Aug. 25, 1993]