Solar Charge Controller.

I have 100 watts solar with Renogy Controller. When my battery fully charge and without load. My battery voltage is around 14.55 Volts. I believe that is the voltage of the controller. Is that bad for the battery?

Comments

  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,760
    How are you monitoring the battery voltage?  Battery monitor, plug in meter, multimeter, SeeLevel monitor?
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • huanvanhohuanvanho Member Posts: 47
    Yes. I checked the battery voltage with a multimeter. At full battery, the solar controller is @ 14.55Volts and the battery is also 14.55 Volts
  • Denny16Denny16 Member Posts: 5,431
    edited October 2020
    Is this a lithium battery or?
    cheers
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • huanvanhohuanvanho Member Posts: 47
    It is just a normal Seal  deep cycle marine battery
  • pthomas745pthomas745 Moderator Posts: 3,989
    You are testing the battery at the battery terminals?  Or using your meter on the terminals at the solar controller?

    2017 Outback
    Towed by 2014 Touareg TDi
  • Denny16Denny16 Member Posts: 5,431
    edited October 2020
    Try disconnecting the battery from the ground side of the battery, and retest the battery at the terminals.  A sealed marine battery should be at 13.x VDC fully charged, unlikely it would measure 14.+ VDC.
    cheers
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,760
    @huanvanho - what settings did you apply to your solar charge controller?
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • huanvanhohuanvanho Member Posts: 47
    The Solar is default which I can't set it. SI think the controller put out 14.55 Volts is too high. I am going to return and buy different controller. I think the controller charger should be between 13.6 to 14.2 V

  • Tundra57Tundra57 Member Posts: 640
    Stick with the Vicron smart solar chargers. I have renogy solar cells but use a smart solar controller. It talks to the factory solar smart solar when you have the Vicron BMV bluetooth remote voltmeter/current meter.
    Everything works really well together.
    If the Renogy controller is over 14v, it is most likely stuck in the wrong charge mode, trying to fast charge the battery. If you disconnect the solar controller the battery voltage will fall to the normal level as mentioned by others above.
  • Denny16Denny16 Member Posts: 5,431
    OK, had sun today and did a test.  With fairly full sun thenVictron voltage meter showed 14.5-15 VDC (trailer spent the previous three months inside), after the sun set, it read 13.x VDC, so the meter shows the voltage coming from the solar panels going to the battery in the day, until the battery is charged, than the MPPT cuts the volts to the battery down to a small charge level.  So the OP getting 14.x VDC reading with solar panels is nominal.
    cheers
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,760
    @Denny16 - so, it may be normal for the controller to output a voltage of 14-15 during bulk, but, the battery overcharged because the controller did not reduce voltage?

    @huanvanho - did you turn off the battery switch and test the battery voltage after it rested (after dark when the solar is not generating volts)?
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • Denny16Denny16 Member Posts: 5,431
    edited October 2020
    The controller will only output the higher voltage if the battery is below its nominal voltage level, a properly working solar controller is not going to overcharge a battery.  My original point was, if the OP is seeing 14.x VDC on his meter, the solar system is charging his battery, and what he is seeing is not the actual battery voltage.  Or, their is a load on the battery that is greater than the threshold level, in which case the solar  will add watts to help feed the current drain, and again you will see a higher than normal battery voltage. 

    This is not going to harm battery. Overcharging is an issue with lead acid batteries where you can actually boil the acid in the cells, and overheat the battery.  

    My battery was down after bing in the shop (indoors) for three months so battery volt was below nominal, and got charged.  Last night, battery read 13.5+ VDC with no charge being applied, so close to an actual correct voltage level.  Still this is not an accurate isolated battery voltage check.
    cheers
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • huanvanhohuanvanho Member Posts: 47
    After the dark. My battery went back down to 13.0 Volts. So I guess this is normal
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