Forum Discussion

doug90000's avatar
doug90000
Explorer
Jan 02, 2017

Voltage drop from convertor to batteries?

I have a 2015 Keystone Cougar. From day one I've had trouble keeping the batteries charged.We don't dry camp often so it's no big deal. Finally got around to trying to figure it out.

I pulled the convertor out and bench tested it and the output was 13.7 VDC. Re-installled and checked the panel input voltage 113VAC.

Checked the voltage at the DC lugs in the battery compartment with batteries removed and the voltage is 7.5 VDC.

I do have the auto leveling system and I assume its installed between the convertor and the batteries. None the less it was off and shouldn't have been drawing much power.

Has anyone else had this issue?
  • laknox's avatar
    laknox
    Nomad
    Jan 03, 2017
    DReisinger wrote:
    Check the battery disconnect, mine is by the door down low, apparently it had gotten bumped and turned off, replaced the converter, still low voltage at battery, flipped the switch and back in business.


    My disconnect, when open, will show 0v, as it cuts off the battery charging connection along with everything else. Found that out the hard way. The only way I get =any= voltage from the converter is with the disconnect closed. YMMV...

    Lyle
  • DReisinger's avatar
    DReisinger
    Explorer
    Jan 03, 2017
    Check the battery disconnect, mine is by the door down low, apparently it had gotten bumped and turned off, replaced the converter, still low voltage at battery, flipped the switch and back in business.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Jan 03, 2017
    Converter output goes thru 'reverse polarity' fuses then thru an in-line fuse (or DC circuit breaker) then to battery positive terminal (maybe thru a disconnect switch if equipped)

    NEG cable will go directly to battery NEG terminal along with NEG cable to frame for ground

    YOU have a bad connection (loose/corroded etc) on POS or NEG wiring

    Just start measuring DC Voltage at each junction
  • Sam_Spade's avatar
    Sam_Spade
    Explorer
    Jan 03, 2017
    doug90000 wrote:

    Checked the voltage at the DC lugs in the battery compartment with batteries removed and the voltage is 7.5 VDC.


    You need to check the voltage output AT THE CONVERTER under the same circumstances; that is within a minute or two of the above measurement.

    With the batteries removed, there shouldn't be enough current to make an actual voltage drop so the best guess is a REALLY bad connection between battery and converter somewhere.
  • time2roll's avatar
    time2roll
    Nomad
    Jan 03, 2017
    13.7 to 7.5 is huge. Especially with no load. Almost as if a switch is off or the self resetting breaker is shot. Anyway you need to trace out the connections. With no battery the voltage at the converter and the battery should be identical. Start poking your meter on every connection until you find 13.7 on one side and 7.7 on the other and fix that item or connection. Could also be at the ground connection to the frame.
  • enblethen's avatar
    enblethen
    Nomad
    Jan 02, 2017
    Your incoming voltage is a little low, but no the problem.
    Sounds like a bad connection.
    Verify voltage in 12 volt DC distribution center. Check both sides of the BAT fuse.
    Check ground connection on tongue of the rig where the ground wire attaches.
    Look under tongue where the umbilical cord from TV connects to battery positive wire for a circuit breaker or fuse. Doubt whether it is tripped, more likely to be corroded.
  • sch911's avatar
    sch911
    Explorer
    Jan 02, 2017
    I would check it again with the battery connected to be sure.
  • ScottG's avatar
    ScottG
    Nomad
    Jan 02, 2017
    My guess is you have a DC breaker someplace that has failed or at least you have a very bad connection someplace.
    They hide breakers in the craziest places sometimes.I would follow the charge wire.
    Also make sure the reverse polarity fuses on the converter are still good.

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