Voltage "Settling" after sundown

The Only SargeThe Only Sarge Solar Expert Posts: 164 ✭✭✭✭✭
I wish to insure I understand this 'settling".

I am keeping a log (learning tool for me) on the status of various parts of my system during the day/night/cloudy etc.

So today full sun. Voltage went to 14.2 by 10am on my batteries. Controller (MorningStar 20 amp) went into PWM and stayed there all day. Sun is down and the battery voltage is showing 13.1 with no load. My Google Fu skills return this as "settling"....is this correct and normal?

Comments

  • SlappySlappy Solar Expert Posts: 251 ✭✭✭✭✭✭
    Re: Voltage "Settling" after sundown

    yes very normal, it is called a "surface charge". it will very on battery type and the amount of time it has settled sense charge and the battery condition,and ambient temp, but the average is around 13.2 volts, and some as low as 12.8.
  • The Only SargeThe Only Sarge Solar Expert Posts: 164 ✭✭✭✭✭
    Re: Voltage "Settling" after sundown
    Slappy wrote: »
    yes very normal, it is called a "surface charge". it will very on battery type and the amount of time it has settled sense charge and the battery condition,and ambient temp, but the average is around 13.2 volts, and some as low as 12.8.

    Thank you Slappy.......
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Voltage "Settling" after sundown

    You've probably read the battery FAQ's already: http://www.windsun.com/Batteries/Battery_FAQ.htm

    So let's look at what's going on: it's working. :D
    Charging has 3 stages. In the first Bulk stage it pushes as much current as is available to get the Voltage up to the Absorb set point. That's your 14.2, which it will hold for a period of time or until the current drops below a preset level (depending on charge controller and programming). Then it will settle down to Float, which is a lower Voltage that allows the panels to power most things without drawing off the batteries. This is usually 13.8 Volts, but again varies with the controller and its settings.

    If you leave a "12 Volt" battery sit with no load and no charging over night you can expect a Voltage reading of 12.7 or so. Why does yours read 13.1? Could be a bit of charge still coming from the panels, could be a bit of "surface charge", could be the inevitable difference between one Volt meter and another.

    How much easier this would all be if a "12 Volt" battery put out 12 Volts! :p
  • The Only SargeThe Only Sarge Solar Expert Posts: 164 ✭✭✭✭✭
    Re: Voltage "Settling" after sundown
    You've probably read the battery FAQ's already: http://www.windsun.com/Batteries/Battery_FAQ.htm

    So let's look at what's going on: it's working. :D
    Charging has 3 stages. In the first Bulk stage it pushes as much current as is available to get the Voltage up to the Absorb set point. That's your 14.2, which it will hold for a period of time or until the current drops below a preset level (depending on charge controller and programming). Then it will settle down to Float, which is a lower Voltage that allows the panels to power most things without drawing off the batteries. This is usually 13.8 Volts, but again varies with the controller and its settings.

    If you leave a "12 Volt" battery sit with no load and no charging over night you can expect a Voltage reading of 12.7 or so. Why does yours read 13.1? Could be a bit of charge still coming from the panels, could be a bit of "surface charge", could be the inevitable difference between one Volt meter and another.

    How much easier this would all be if a "12 Volt" battery put out 12 Volts! :p

    Makes sense and I am learning. Yes there was some sunlight left on the panels.

    You think batteries will make you crazy you should try high performance race engines.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Voltage "Settling" after sundown
    Makes sense and I am learning. Yes there was some sunlight left on the panels.

    You think batteries will make you crazy you should try high performance race engines.

    Actually, I have: http://kaleidopsyche.deviantart.com/gallery/1293140?offset=72#/dohw1f
    :p
  • The Only SargeThe Only Sarge Solar Expert Posts: 164 ✭✭✭✭✭
    Re: Voltage "Settling" after sundown

    Lord help us then.
    100_1093.jpg
    100_1094.jpg
  • TheBackRoadsTheBackRoads Solar Expert Posts: 274 ✭✭✭✭✭✭
    Re: Voltage "Settling" after sundown

    Hemi represent!! ;):D8)

    attachment.php?attachmentid=1776&stc=1&d=1305152172

    These are some sick rides guys! lol. Seems very umm whats the word.. contradicting. hehe 8)
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