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Wednesday, September 7, 2016

What To Do When Your Solar Charging System Fails!

New Panels
    Don't Panic. I've been working on improving my original Solar Charging System for the past few years. The Current System is working very well. Lots more power, great charge times and no stress from difficult maintenance. Yay! Then Murphy strikes. On my last trip, I awoke to see I was not charging AT ALL. Nada, nothing. Bad. Very Bad. I had just replaced all the Second Generation prototype panels with brand new Third Generation panels that shouldn't have any of the vibration related problems the Second Generation ones did. Bear in mind I hadn't had ANY coffee yet, so this was a shocker. Since my panels are adhered to the roof with paralastic adhesive AND I now have six panels, this could have been a huge amount of work to remove, clean and replace...again.

Remote Solar Charge Meter
So, I first checked a few things inside. The solar charging controller, the wiring going into it from the panels, the main battery switches and even the wall and dash mounted remote meters. All was in order, no weirdness. Except, I was only seeing 12.5 Volts coming down from the panels. This was bad, very bad. Last time the voltage dropped like that, the panels were finally dying. At that point, I figured it was either a break in the duplex (2 conductor+insulating sheath) wires coming from the roof or the panels themselves. So, after making breakfast, having another cup of percolator coffee and watching the ZERO watts indication on the charging monitor I decided to make a last ditch effort to check the panels on the roof. It was VERY hot and sunny (perfect charging weather, actually) so I didn't want to spend too much time up there. Besides, I was on vacation! Grabbed my multimeter and climbed the ladder.

They LOOK Tight, But Aren't!
Once there, I opened one of the three junction boxes and set the tester to DC Volts. It indicated 17.34 Volts from the panels. Huh? If there was a break in the line and the panels were working I should see a bit more volts with no load (open circuit) If the panels were dead, I should see much less volts (12.5 like on the meter.) What was going on here??? Inside the junction boxes are several screw terminals. Each panel has a positive and negative wire coming out and there are a positive and a negative wire leading down to the charge controller. They are connected at the screw terminal (each has a ring terminal crimped/soldered on the end) and the screw tightened down to make a good electrical contact. Except in this case, they weren't! Every screw was loose. Not completely, but enough that the electricity wasn't flowing properly. Must have been the vibration from the drive there that did it.

So, after tightening them all down, I was back in business. Lots of Amps flowing into the batteries. All was well. I breathed a MAJOR sigh of relief. This could have ended far differently. Next step? Trying to come up with a more secure and vibration resistant solution for the terminals. But that's another story....

Be Seeing You...Down The Road,

Rich "The Wanderman"
www.thewanderman.com

10 comments:

  1. Hey Rich, have you tried lock washers to hold em tight? Simple and inexpensive.

    ReplyDelete
    Replies
    1. Larry,
      There are/were lock washers on there. It's really all about the mechanical "squeeze" power of the small screws. I am going to try some heftier nuts/bolts/washers inside the junction box.

      Thanks!

      Rich "The Wanderman"

      Delete
    2. Rich, how about star washers. A bit more bite with them.

      Delete
    3. Anon,
      I am sure it's the plate the screw actually goes into rather than the screw itself. It simply isn't all that robust.

      Rich "The Wanderman"

      Delete
  2. Lock tite or simple women nail polish ! on the threads and over the connection

    ReplyDelete
  3. Rich. Recenty bought new 5 wheel. Have used solar panels for well over 20 yrs. removed old panels from old unit and will use on smaller trailer. I see you have installed flex panels . I need to do same on new unit before Nov. can you suggest source for panels. Keith

    ReplyDelete
    Replies
    1. Keith,
      I've been bulk buying panels and customizing the size recently. They are sourced from MANY manufacturers, but I recommend BACK CONTACT panels for their vibration resistance.

      Rich "The Wanderman"

      Delete
  4. My solar system seemingly took a dump earlier this year during our annual "shake down" trip, which we take to a local state park. For no apparent reason I was getting NO charge from my 375 watt array. Using an 'amp clamp' I determined that there was about 18 volts coming down the wire but not making it past the controller mounted in the storage area. After several calls to the controller mfg (Morningstar), I was able to convince the 'tech' that my controller was at fault. They sent me a brand new one. I just had to return the failed one in a pre-paid shipping box. After some anxious deliberation, we're back to 'energy independence'. Whew!

    ReplyDelete
    Replies
    1. Tommy,
      Seriously scary after all the fiddling and expense to get off grid. I feel your pain!
      I'm also using a Morningstar controller (TS-45-MPPT)

      Thanks,

      Rich "The Wanderman"

      Delete

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