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Vintage465's avatar
Vintage465
Nomad
Oct 18, 2015

How's my "6v" Solar working?

So when I bought my new trailer it came with 300w of solar and a Samlex controller. When I first got the trailer home I installed one of the old 12v batteries from my old trailer and it regularly read 13.7 to 14.4v. Before leaving on my vacation I purchased two Interstate 6v batteries and wired them in series. This set up will read a maximum of 13.4(no load)when the sun is shining and the solar is charging. When the sun is gone the voltage is dropped to 12.9, maybe 13.0v. I didn't really get a chance to put them to the test as we were staying in RV parks most of the time. If I spent the night somewhere and didn't plug in the voltage dropped to around 12.6-ish over night. "overnight" would have included the average careful usage of lights, and a C-Pap running all night w/o the humidifier. So I guess my first question is: Is it normal for a pair of six volts to register a lower surface or peak voltage than a single 12v?

Thanks,

10 Replies

  • 2oldman's avatar
    2oldman
    Explorer II
    Oct 18, 2015
    Vintage465 wrote:
    If I spent the night somewhere and didn't plug in the voltage dropped to around 12.6-ish over night. "overnight" would have included the average careful usage of lights, and a C-Pap running all night w/o the humidifier.
    That's very good performance.
  • time2roll's avatar
    time2roll
    Nomad
    Oct 18, 2015
    Seems fine to me. You probably just missed the ramp up to 14.4 before Samlex dropped to float.

    12.6 in the morning after light use indicates all is well.
  • Vintage465's avatar
    Vintage465
    Nomad
    Oct 18, 2015
    I suppose I will actually find out when I go to the desert for a week and run the heater a couple nights!
  • Vulcan_Rider's avatar
    Vulcan_Rider
    Explorer
    Oct 18, 2015
    BFL13 wrote:

    Your two 6s seem to be working well.


    You put in the new batteries to get a higher capacity.

    Among other things, that means that they need more charging capacity too. Your present solar may not be able to give them enough charge fast enough to really care for the new ones properly.

    IF....you had a long, bright sunny day and the batteries started out close to fully charged.....you might see a higher charging voltage than what you have seen so far but I kind of doubt it.

    Or to put it another way, it might take the present solar system several days to fully recover from one healthy overnight discharge if no other charging source is used.
  • grizzzman's avatar
    grizzzman
    Explorer
    Oct 18, 2015
    RJsfishin wrote:
    I think your voltages are not right.
    A 12v battery is usually not over 12.8 volts after a 48 hr rest and no load.
    And more in reality, a full charged non AGM will read more like 12.6-7
    If you were reading 13v or more, you are still seeing the charging voltage


    About 5 months ago i charged a newish set of 232 AH 6 volt interstates and resting voltage the next day showed over 13 volts.
    Sounds like normal voltage for new interstate batteries.
  • grizzzman's avatar
    grizzzman
    Explorer
    Oct 18, 2015
    Vintage465 wrote:
    So when I bought my new trailer it came with 300w of solar and a Samlex controller. When I first got the trailer home I installed one of the old 12v batteries from my old trailer and it regularly read 13.7 to 14.4v. Before leaving on my vacation I purchased two Interstate 6v batteries and wired them in series. This set up will read a maximum of 13.4(no load)when the sun is shining and the solar is charging. When the sun is gone the voltage is dropped to 12.9, maybe 13.0v. I didn't really get a chance to put them to the test as we were staying in RV parks most of the time. If I spent the night somewhere and didn't plug in the voltage dropped to around 12.6-ish over night. "overnight" would have included the average careful usage of lights, and a C-Pap running all night w/o the humidifier. So I guess my first question is: Is it normal for a pair of six volts to register a lower surface or peak voltage than a single 12v?

    Thanks,


    Have you removed the controller from the wall and checked the dip switches? Dip 1 = 12 volt system. Interstate recommends 14.7 now and equalize at 15.3 volts. Set the 3,4,5 dip switches at either on,off,on (this will set bulk at 14.6 or on,off,off 14.8 volts. Have fun with your solar!
  • RJsfishin's avatar
    RJsfishin
    Explorer
    Oct 18, 2015
    I think your voltages are not right.
    A 12v battery is usually not over 12.8 volts after a 48 hr rest and no load.
    And more in reality, a full charged non AGM will read more like 12.6-7
    If you were reading 13v or more, you are still seeing the charging voltage
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Oct 18, 2015
    Never assssssume you are not being lied to by your instrumentation. Verify. Corroborate accuracy. 13.4 is float voltage territory. What do you see for absorbsion limit?
  • BFL13's avatar
    BFL13
    Explorer II
    Oct 18, 2015
    The solar puts the same AH in which will fill a single battery higher than it will two batts.

    Your two 6s seem to be working well.

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