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crosscheck's avatar
crosscheck
Explorer II
Feb 06, 2014

Broken Stud Terminal- Secure Your Batteries

Thought I would put this problem in general rv as this has more to do with the problems when batteries bang around.

I have 4 (6V)batteries that are housed in a battery box that sits in the basement under the dinette. There is room on 2 sides of the box when batteries are snug on other two sides.

Used what I thought was ample materials to keep batteries from moving on rough roads. The terminals have a combination of an automotive post and a stud terminal. Very stiff cables are attached to the stud terminals joining the batteries so they are wired for standard 12V application.

After a trip last spring, was checking the battery cables and found one of the stud terminals discolored. Because of the movement of the batteries during rough, washboard and pot holed roads, batteries had moved around enough to put pressure on the cables which in turn broke the lead which the terminal bolt is incased in.

I have since made sure that the batteries are now solid and have put steel connectors onto the posts and then connected them to the cables giving them a much stronger connection.

Only one of the terminal studs was broken but they are only a bolt that is encased in relatively weak lead. When we turned on the micro, that probably is when the broken connection wire got hot.

Has anyone else had this issue?

Dave

6 Replies

  • I built a DC distribution panel and chewed through about 50' of 4 AWG in the process. I used multistrand welding wire. It is similar to the Ancor marine wire only each strand isn't tinned like the marine stuff. I use a hammer-crimper to attach the lugs.



    Working side of DC panel:



    The three master switches allow switching between two battery banks for the solar controller, the converter, and the inverter.
  • I would at least run a strap around all 4 batteries to keep them from separating again. Obviously, a fitted enclosure with hold down bars and base edge support is the best solution. Until you get them strapped from moving vertically, make sure the terminals won't hit metal above...some kind of insulating layer above is needed till you get them all secured.

    That marine wire that RoyB got, works very well and is extremely easy to bend. I got the exact same rig as he did, and my crimper came from Harbor Freight, but it works well. One advantage of making your own cables is drilling smaller holes to feed wire (through walls or bulkheads) with a grommet already in place, for a perfect fit, before you attach the terminal ends. Oh yeah, and way cheaper.
  • Harvey51 wrote:
    Odd, I wouldn't have thought the terminals were designed for mechanical support. Engine batteries are supported by steel brackets. Our RV batteries have a heavy belt around each battery. Terminals only support the wires.


    Battery box is larger than the 4 6V batteries, so they need to be wedged in. They sit on the bottom of the box. The batteries each came with an automotive post and a stud terminal(3/4" bolt incased in lead). Heavy, very stiff wire cables connects the 4 batteries on the stud terminals so you have 2 12V batteries with 400 amp/hrs in total. When batteries moved, connector terminals(bolt) broke the lead leading to arcing.

    Now I have a steel connector on the post with a stud connector attached to the steel plate and the connecting cables are attached to these much stronger studs.

    The only thing holding the batteries in the box is wood materials wedged up against the them.

    Hope this makes sense.

    Dave
  • Odd, I wouldn't have thought the terminals were designed for mechanical support. Engine batteries are supported by steel brackets. Our RV batteries have a heavy belt around each battery. Terminals only support the wires.
  • Yup, terminal studs are notorious for that type of failure. it's good that you found it before total disconnection. I believe you can repair the stud.
  • RoyB's avatar
    RoyB
    Explorer II
    I would use flexible marine grade quality wiring. I used ANCOR cables with excellent results...

    as you can see from these google search photos the cables are very flexible and can be cut to your exact length and fitted with proper ANCOR RING TERMINALS using adhesive heat shrink ends.

    I ordered all of ANCOR CABLES in 25-foot lengths with proper sized ring terminals from ebay sales places...

    I used one of these hydraulic hand crimper tools from AMAZON...

    My idea was all cable connections use stud type connections everywhere using ring terminals. All of my connection points are usually BLUE SEA units battery switches, fuse blocks, terminal blocks, etc all using stud connections. All BLUE SEA products can be ordered from AMAZON.

    This makes for great installs and matching of zone lengths for the cables to match up your required loads etc...








    All photos from Google search

    Roy Ken

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