Car Battery

Discussion in 'General Electronics Chat' started by ihaveaquestion, Aug 22, 2009.

  1. ihaveaquestion

    Thread Starter Active Member

    May 1, 2009
    Some guy at the car place was trying to find out why my car battery keeps dying.

    He applied some device to it to keep "adding a load" to it which I interpret as adding more and more resistance for a given voltage.

    He said "feel it" because the terminals were getting more and more hot, which is bad I guess, because there was a bigger and bigger current flowing which is not what we want?

    From my understanding, a car battery is DC, so it follows Ohm's Law....

    V = IR

    So if he's applying a larger and larger "load" or resistance

    I = V / R, wouldn't the current get SMALLER with a bigger load?

  2. bertus


    Apr 5, 2008
  3. someonesdad

    Senior Member

    Jul 7, 2009
    He was probably using a carbon pile resistor to apply the load to the battery. To increase the current, he decreases the resistance. The device he was using may appeared to have been "increasing the load", but what it was actually doing was decreasing a resistance.