Extending DC battery life

Discussion in 'The Projects Forum' started by Ishkabibble, Jun 20, 2011.

  1. Ishkabibble

    Thread Starter New Member

    Apr 18, 2011
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    I was recently talking to a man that had a special high efficiency controller built for his 12V DC boat motor. Apparently it tripled his battery life and gave him greater control over the amount of thrust his motor generated. Can anyone advise me on what type of controller this might be?
     
  2. wayneh

    Expert

    Sep 9, 2010
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    Was he offering any magic beans as well? I'm skeptical, not that he has an efficient controller, but that the normal controllers would be so bad.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
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    He may have obtained a PWM motor controller. Operating a motor from a battery with a reduced average current would allow operation over a longer period of time; as there will be less power dissipation in the battery itself and more in the motor.

    However, there is nothing "magic" about that. The total power expended would be the same. The motor would be operating at a much reduced speed.
     
  4. #12

    Expert

    Nov 30, 2010
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    I'd vote for the PWM controller but I dread seeing, "Can you design one for me?"

    Ishkabibble: try to read the label on the controller. Brand name, model number, such as that. or ask the friend that owns it about the brand name and model.
     
  5. wayneh

    Expert

    Sep 9, 2010
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    Yes, PWM is "state of the art" for such things. But is it really possible that his old, inefficient controller was a linear device and not already PWM? I'd be surprised if that were true, but I guess if it was old enough... I certainly have no knowledge of the history of PWM for boat motor control.
     
  6. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    There are a lot of cheap proven kits for PWM speed control of medium sized DC motors.

    You could google for "20 amp PWM DC motor speed controller kit".
     
  7. Ishkabibble

    Thread Starter New Member

    Apr 18, 2011
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    Thanks everyone. I doubt I'll meet the man again, so I have to more or less go on what he said. Given that he was moving a small kayak, I'm guessing the added duration came more from reduced RPM than the PWM function. I too move a small boat, so I will try the 20 Amp PWM speed controller kit suggestion.

    Cheers!
     
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