Battery Problem

Discussion in 'Boats and Motors' started by guppygill, Sep 8, 2008.

  1. Neighbor has a 1972 Evinrude. He purchased an Energizer battery from Sams Club. He has been going out with no problems until today. He states when he got out to the lake, battery was dead. No electronics left on, but sometimes he stated he leaves the key turned to the right a little. I suggested charging it up, then use a voltmeter before he leaves, and while he is on the water to check to see if it is being charged. Anything else to check what drained the battery?


  2. Could be a bad battery. Happens occasionally. Did with my B.I.L.

    Also check with an ohmmeter across the terminals with the switch "turned to the right a little" and the battery disconnected.

  3. freyedknot

    freyedknot useless poster

    could be his alternator on the motor is not putting out any voltage and is just running on the battery.
  4. I had one once that drove me crazy ( I know...short trip :)) It would let me down on the lake and test good at the dealer. Turned out to have a loose plate in it that when bounced around, touched the one beside it, creating a dead short.
  5. is he sure a 1972 motor has a charging ability?
  6. UFM82

    UFM82 The one others want to be

    We'll assume it's an electric start engine and has cables that run to the battery. The size of the engine will help determine what charging capability it has. Even a small electric start engine will provide some charging ability even if it's only a 6 amp magneto charging system. Larger models may or may not have an alternator.
    The easiest way to check for a "draw", which is current being used even when all accessories are off is to remove the negative cable from the battery terminal and hook a 12V test light in series between the cable and the terminal. If you do have a draw, the light will illuminate. Even a dim light is excessive within a 12V system. The light should stay unlit. If you do get a light, isolate the draw by removing any circuit from the system. If you have a fuse block on the boat, remove the fuses one at a time and watch the light. If it goes out, you've found the circuit. Then isolate the accessory. Radios, depth finders, bilge pumps all can cause draws although usually you'll see or hear something unusual with those. You can also have a draw from the engine itself if you have a bad rectifier/voltage regulator and/or alternator. A sticky ignition switch can also cause issues as you might have already determined.

    Short of a bad battery, which can be possible, that's what about all that will drain a battery. When you charge the battery and check it with a voltmeter, you should see a reading of at least 12.7 volts on a fully charged battery. If you ever see a reading below 11 volts, you have a bad cell. The battery MAY crank the engine at that voltage but it will be weak and will strand you. If that is the case, replace the battery.

    If you find that you have a draw in the engine and do not want to spend the money to have the charging system diagnosed/repaired, you can either disconnect the battery each time you come off the water or install a battery switch in the boat somewhere. That will isolate the engine from the battery and prevent a dead battery. That's a band-aid fix but a fix nonetheless.

  7. Thanks everyone, I will print this out and give to him. Forgot to say, it is a 50 horsepower, they did have alternators on them back in 1972, correct?
  8. UFM82

    UFM82 The one others want to be

    Magneto charging at that 6 amp rate or so. There's no accessories on that engine- just the current that is produced as the magneto is turned, It's part of AND under the flywheel.

  9. Does he have a radio/CD player? I was told memory station presets would slowly draw your battery down. I just disconnect the negative terminal before charging and reconnect each time before going out.
  10. KaGee

    KaGee Monkeywrench Staff Member

    The draw is so little it would take a long time to drain the battery.

    Those old alternators do not recharge the battery at a very fast rate. It's possible that he's just draining the battery faster than it can be re-charged. I always threw mine on a charger before going out.
  11. Thanks, will forward the info to him.
  12. Excellent post UFM82, you're a credit to the OGF.