I hate intermittent problems - batt charger not starting up

Discussion in 'Musings With Maine Sail' started by Ed Caldwell, Apr 8, 2019. Add this thread to a FAQ

  1. Ed Caldwell

    Ed Caldwell

    Joined Jul 29, 2004
    333 posts, 63 likes
    Hunter 340
    US Lake Lanier, GA
    Xantrex Trucharge 40, now about 14 years old, replaced as part of a lightning repair on this 20 year old boat. This weekend, for the 3rd time in 9 months, when I plugged into shore power and flipped on the panel breaker, the charger failed to immediately start up despite the voltage being down below 12.6v. Normal behaviour is that it immediately starts charging, as indicated by the Link 20 volts/amps and the sound of the cooling fan. All other shore power circuits working as normal. I flipped the panel switch on/off several times over the course of a half hour or so. Then I left the boat for about 6 hours (leaving the charger circuit turned on) and when I returned found the batteries fully charged. Of the three failures, two have recovered like this, one time, I started the engine and the charger came on.

    Thinking through what might cause this, I believe it could be the breaker on the shore power panel, the connection there or at the battery charger, or the charger itself. Any ideas how/where to troubleshoot, or should I just wait for something to stay broken...
     


  2. Bill19233

    Bill19233

    Joined Jan 22, 2008
    452 posts, 350 likes
    Hunter 340
    US Baytown TX
    Look for loose, corroded, or blackened connections on the AC breakers on the back of the panel. I had an intermittent open on a loose DC breaker connection that was a quick fix just tightening it. Check and tighten all of them while you got the panel off. An electrician told me thermal expansion cycling on the wires and terminals on high current circuits will loosen even the tightest screwed down connections on your boat panels and home breaker panels. He said he checks his home panel annually. He does it with power on with the right tools, I would turn the main or each breaker off before I stuck a screwdriver on it.
    If the charger is coming on, but not charging, then that's not it. Open it up, you might get lucky and see the problem inside the charger, loose solder landing, burned out component. Good luck with it Ed.
     


  3. Don S/V ILLusion

    Don S/V ILLusion

    Joined Sep 25, 2008
    5,388 posts, 507 likes
    Alden 50
    US Sarasota, Florida
    If it’s 14 years old, you got your money’s worth
     


  4. Brian D

    Brian D Moderator

    Joined Feb 17, 2006
    4,454 posts, 1,087 likes
    Lancer 27PS
    US MCB Camp Pendleton, Ca KF6BL
    Break out the DVM and start tracing the circuit either from the panel to the charger, or from the charger to the panel. Don't chase rabbits. Remember, you charger will not turn on if it does not detect a battery.
     


  5. Davidasailor26

    Davidasailor26

    Joined May 17, 2004
    1,776 posts, 467 likes
    Beneteau Oceanis 37 LE
    US Havre de Grace
    +1 for this. The fact that at least once the charger came on after the engine started is interesting. Makes me think that either (1) there's a bad connection that was shaken into place by the engine vibration, or (2) the added voltage from the engine made the charger realize that there are actually batteries connected.
     


  6. uncledom

    uncledom

    Joined Jun 11, 2011
    1,175 posts, 270 likes
    Hunter 41
    US Lewes
    What is your battery voltage at rest before you charge? Most chargers have a low voltage cutoff where they won't start charging unless the battery voltage is above a certain number.
     


  7. Ed Caldwell

    Ed Caldwell

    Joined Jul 29, 2004
    333 posts, 63 likes
    Hunter 340
    US Lake Lanier, GA
    Thanks all for your replies and suggestions!
    I haven't opened the panel yet to look, but I agree, anything that looks amiss will be addressed. I also thought about swapping the leads going to the microwave and battery charger and see if the problem moves to the microwave. But I have to wait until another failure.
    BrianD, agree if all looks ok behind the panel, this is next.
    I agree, it's led a long and happy life, but I don't want to just start replacing parts unless I know where the problem is. Will be going with Maine's battery charger when needed, if it will fit.
    Good point, But you'd think that if it is a loose/intermittent/connection it would show up as a problem sometime while the charger is turned on and working. I assume the charger would also shut down if the connection to the battery is broken? Each time the problem has happened, it's been after a discharge/unplug time of 15-36 hours, and I try to turn the charger back on.
    I try to never discharge the house batteries below about 12.1 or 12.2 volts. Last weekend, the problem occured at about 12.55v after about a 15 hour unplug time and a light refrigeration load.
     


  8. Ed Caldwell

    Ed Caldwell

    Joined Jul 29, 2004
    333 posts, 63 likes
    Hunter 340
    US Lake Lanier, GA
    David, agree that is a possibility to check. I believe the guy who installed the charger wire to the house bank may have led it to the post on the battery switch instead of directly to the battery, so it's a good time to check and correct that if he did.
     


  9. Ed Caldwell

    Ed Caldwell

    Joined Jul 29, 2004
    333 posts, 63 likes
    Hunter 340
    US Lake Lanier, GA
    An update from this weekend. Took the boat out for a short cruise, came back in and plugged back in to shore power, battery charger started right up. Turned it back off for overnight, the next morning turned it on and did not power up. Checked behind the panel, found 120v on the load side of the breaker, so that eliminates the easy fix. All connections were tight on the panel back side.

    Moved to the batt charger input, opened the cover on the connections, found 3 butt splices (I had turned off the power again), pulled the wires out to examine the splices and try to stick the VOM probe in to see if power was present on the charger side of the splice. Turned the breaker back on to try to measure voltage, and of course, the batt charger started right up. Interesting similarities to the 3 other intermittent events were the overnight discharge (about 55 AH) and the 45-60 minute interval between power first applied that morning and when the charger turned itself on.

    The splices look and feel ok, I tugged on them pretty hard. They are not Mainesail approved, done with a dimple crimper. Charger output is being directed to the battery switch posts, not direct to the batteries, again as I suspected. Distances between batteries, switch and charger are very short, everything within less than 2ft wire length. Battery switch back side is a pain to get to, so I didn't get a chance to check those nuts.

    Left for another day, but I am beginning to suspect the charger having intermittent problems sensing the batteries...
     


    Brian D likes this.
  10. Brian D

    Brian D Moderator

    Joined Feb 17, 2006
    4,454 posts, 1,087 likes
    Lancer 27PS
    US MCB Camp Pendleton, Ca KF6BL
    Full speed ahead!
     


  11. Davidasailor26

    Davidasailor26

    Joined May 17, 2004
    1,776 posts, 467 likes
    Beneteau Oceanis 37 LE
    US Havre de Grace
    That would be my guess too. How are the charging rates once the charger comes on? If there were a flaky connection that prevented the charger from seeing the batteries then I would expect the charging rate to be hurt

    Did you by any chance check the voltage of the batteries, both at the battery terminals and at the charger end, while the charger was disabled?
     


  12. Ed Caldwell

    Ed Caldwell

    Joined Jul 29, 2004
    333 posts, 63 likes
    Hunter 340
    US Lake Lanier, GA
    Charging rate quickly went to 36-38 amps as shown on the Link 20.

    I did not measure the voltage directly but it was showing 12.55v before the charger started up again on the Link 20.
     


  13. Brian D

    Brian D Moderator

    Joined Feb 17, 2006
    4,454 posts, 1,087 likes
    Lancer 27PS
    US MCB Camp Pendleton, Ca KF6BL
    So are you saying that the battery is discharging at night when you turn everything off? Maybe I am misreading, but that is what it sounds like to me.
     


  14. Ed Caldwell

    Ed Caldwell

    Joined Jul 29, 2004
    333 posts, 63 likes
    Hunter 340
    US Lake Lanier, GA
    Yep. Battery charger is off, batteries are powering refrig, lights, pumps, etc. Sorry if I wasn't clear.
     


  15. Brian D

    Brian D Moderator

    Joined Feb 17, 2006
    4,454 posts, 1,087 likes
    Lancer 27PS
    US MCB Camp Pendleton, Ca KF6BL
    No problem Ed.
     


  16. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,987 posts, 767 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME
    These particular chargers have a fairly high failure rate so 14 years is longer than many of them last...
     




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