load tester

Discussion in 'The Projects Forum' started by ken_678123, Oct 21, 2013.

  1. ken_678123

    Thread Starter New Member

    Oct 21, 2013
    1
    0
    Hi
    I am looking at building a variable load tester for testing batteries and need to incorporate a variable load in the design ..can any one advise what compnanent can be used to acheive this The load should range from 0 - 12amps at 12v

    THANKS
    kEN
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,804
    1,105
    Do you intend to vary the load manually (e.g. by selector switch) or automatically?
    What resolution (step change) in load is required?
    What accuracy?
     
  3. #12

    Expert

    Nov 30, 2010
    16,343
    6,828
    Do you realize you're looking at 150 to 200 watts?
    That size of resistor is rather expensive.
    $75 for the rheostat and $28 for the limiting resistor (1 ohm, 300 watts)
    If size doesn't matter, a bank of headlights might be good enough.
    Whaddaya think?
     
    Last edited: Oct 21, 2013
  4. wayneh

    Expert

    Sep 9, 2010
    12,153
    3,059
    That's what I'd do; 2 headlights would be close to 10A. Visual feedback, good heat dissipation. You could get fancy with an adjustable, constant current controller.
     
  5. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,292
    1,255
    On another forum we have done a couple with FETs soldered to copper pipe using water to cool them. You could also do the same thing with some really big heat sinks.
     
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