batterry discharge and time

Discussion in 'General Electronics Chat' started by superway, Aug 30, 2013.

  1. superway

    Thread Starter Active Member

    Oct 19, 2009

    I have a 12vbattery 7.2AH. If I loaded it 7.2A, the battery will run out within 1 hour, is that right?
    If so, If I loaded it 450mA, will the battery run out in 16 hours?
    Thanks for help

  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    Approximately, but never run it completely out or it won't recharge. Also, if you have a constant resistance, the battery voltage will drop as the battery charge falls. That means less and less current will flow.
  3. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    You might note on your battery that it specifies the 10 or 20 hour rate. You might consider a circuit to disengage the load when the battery reaches 10.5 Volts. Of course, that circuit will consume some energy from the battery, lowering the time available for the load.