Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: Battery charging problem

  1. #1
    Constant Bitrate Juliemac's Avatar
    Join Date
    Apr 2004
    Location
    Upstate NY
    Posts
    115

    Battery charging problem

    I have a secondary battery in the trunk thats not charging correctly.
    Its fed directly from the Alt, via an 80A fuse, 30A relay (only closes when the ignition on), to the battery. The charging cable is 4GA copper.

    I start the car, then turn on the system, let the car run up and away I go.
    But when I stop the car and look at the battery voltage in the trunk, its only a few volts. It looks like the system is drawing from the secondary battery, but not allowing the battery to charge.

    The Alt is giving out enough current (rated at 90A) and the system is drawing 10A to run the Mastero 4.5.

    Its got me stumped guys. Any ideas?
    1981 VW Scirocco, 2L 16v turbo. EEEPC 1000 running Mega Squirt and music.
    Http://www.menloparkrandd.com/scirocco

  2. #2
    Poet Laureate rustyboxx's Avatar
    Join Date
    Feb 2005
    Location
    The Côte d'Azur of England - Hot totty central
    Posts
    1,289
    Do you have it wired up like this?
    Attached Images Attached Images  
    Only true postwhores remember everything they post

    REP CLUB IS DEAD
    LONG LIVE REP CLUB

  3. #3
    Constant Bitrate Juliemac's Avatar
    Join Date
    Apr 2004
    Location
    Upstate NY
    Posts
    115
    Exactly. That should work right?
    1981 VW Scirocco, 2L 16v turbo. EEEPC 1000 running Mega Squirt and music.
    Http://www.menloparkrandd.com/scirocco

  4. #4
    What can I say? I like serial. Curiosity's Avatar
    Join Date
    Mar 2004
    Location
    Florence Yall, BFKY
    Posts
    2,684
    Have you checked the relay and fuses?
    Disconnect the battery, put a meter on the connectors and start the car. Got power?

  5. #5
    Constant Bitrate Juliemac's Avatar
    Join Date
    Apr 2004
    Location
    Upstate NY
    Posts
    115
    If I run with out the computer the battery level goes up and the current on the ammeter shows normal current drain.
    When running the computer, the ammeter shoes a much heavier current draw, but diminishes the secondary battery.
    I am going to recheck the internal power settings and draw. I don't think I made a mistake though.
    1981 VW Scirocco, 2L 16v turbo. EEEPC 1000 running Mega Squirt and music.
    Http://www.menloparkrandd.com/scirocco

  6. #6
    Constant Bitrate
    Join Date
    Aug 2005
    Location
    Near Buffalo, NY
    Posts
    147
    In my opinion you should have a battery isolator. That way the secondary battery is charged after the main. And if your secondary battery is drained by lets say the pc being left on, the main battery will not be dead when you try to start your car. You can get them in different sizes but these are some general ones. Ive done many setups like this in audio installs and it works great every time. http://www.jcwhitney.com/autoparts/B...+10201/c-10101

  7. #7
    What can I say? I like serial. Curiosity's Avatar
    Join Date
    Mar 2004
    Location
    Florence Yall, BFKY
    Posts
    2,684
    Wow. 10A doesn't seem like that much. Does the battery ever charge up full? Maybe it's going bad. If that's all good, I bet something (wire or relay) is getting hot.

  8. #8
    Poet Laureate rustyboxx's Avatar
    Join Date
    Feb 2005
    Location
    The Côte d'Azur of England - Hot totty central
    Posts
    1,289
    Quote Originally Posted by Jcarere
    In my opinion you should have a battery isolator. That way the secondary battery is charged after the main. And if your secondary battery is drained by lets say the pc being left on, the main battery will not be dead when you try to start your car. You can get them in different sizes but these are some general ones. Ive done many setups like this in audio installs and it works great every time. http://www.jcwhitney.com/autoparts/B...+10201/c-10101
    Isn't that what the relay does? Surely the connection between the two batteries is cut off when the alternator is idle (engine off).

    Julie, is the second battery in good condition?
    Only true postwhores remember everything they post

    REP CLUB IS DEAD
    LONG LIVE REP CLUB

  9. #9
    Constant Bitrate Juliemac's Avatar
    Join Date
    Apr 2004
    Location
    Upstate NY
    Posts
    115
    Battery is a mid sized lawn mower battery that can withstand deep discharge.

    I'll deal with it later, I am about to drive 10 hours (there and back) to get a door for my car. This winter, complete chassis strip and rewire after a nice fresh coat of paint!
    1981 VW Scirocco, 2L 16v turbo. EEEPC 1000 running Mega Squirt and music.
    Http://www.menloparkrandd.com/scirocco

  10. #10
    What can I say? I like serial. Curiosity's Avatar
    Join Date
    Mar 2004
    Location
    Florence Yall, BFKY
    Posts
    2,684
    I think most batteries can take a deep discharge, but the longer they stay undercharged the worse off they get. Like if it was at 6V or less for a month it would be very weak and couldn't hold much anymore.

Page 1 of 2 12 LastLast

Similar Threads

  1. All-In-One COTS Solution: AC/DC, Battery, etc.
    By Pwrplayer in forum Power Supplies
    Replies: 4
    Last Post: 01-25-2005, 11:01 PM
  2. inverter + laptop problem
    By javii in forum Power Supplies
    Replies: 9
    Last Post: 01-07-2005, 03:00 PM
  3. MPJA - MECI ASTEC DC-DC Converter
    By Luc in forum General Hardware Discussion
    Replies: 39
    Last Post: 11-22-2004, 10:31 PM
  4. Dual Battery Woes
    By BigRedBee in forum Power Supplies
    Replies: 35
    Last Post: 11-17-2004, 05:52 PM
  5. Newbie Q: Battery Charge Current?
    By Fox_Mulder in forum General Hardware Discussion
    Replies: 17
    Last Post: 09-20-2004, 11:52 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •