Diode Question

Discussion in 'The Projects Forum' started by Phewsion, Sep 24, 2012.

  1. Phewsion

    Thread Starter New Member

    Sep 24, 2012
    Hello All:

    I have a 2 battery setup in parallel. I would like to setup Battery1 to start the vehicle and run the vehicles electronics. Battery 2 I would like to be dedicated to electronics I am installing. This being the case I don't want battery 1 to be able to draw power on Battery 2. However I do want the alternator to charge both batteries. I am thinking about using a diode to prevent the back feed of power. Assuming the batteries are Lead Acid, 800-1200 CCA with an Alternator rated between 90 - 200 amps, and the setup will be exposed to temperatures from -50 thru 180 what type/size Diode would be best for this.

    Also as this is going to be used industrially I would like a packaged solution to this... unfortunately I haven't had any luck finding one.

    I am not an engineer and am just trying to research a resolution to our problem ... Thanks in advance for the help. :)
  2. mrmount

    Active Member

    Dec 5, 2007
  3. cork_ie


    Oct 8, 2011
    Diodes are a pain in the ass as they drop about 0.7V and cause more charging system problems than they cure. GOOGLE "split charge relay"
  4. Phewsion

    Thread Starter New Member

    Sep 24, 2012
    Cork_ie.... U rock. That was exactly what I was looking for. Thank you guys both for helping me with this.