Getting a TRUE full charge of your battery grid

Discussion in 'Energy' started by HaShev, May 24, 2018.

  1. HaShev
    Offline

    HaShev Gold Member

    Joined:
    Jun 19, 2009
    Messages:
    8,016
    Thanks Received:
    679
    Trophy Points:
    205
    Ratings:
    +2,972
    Most solar controllers default at 13.7v trickle charge for 12v battery charging, but batteries require around 14.1-14.5v to top off that last 5% for a true fully charged battery.
    Someone might lower that number not knowing and thinking it's too much for a 12v battery, and others assume the manufacturer would know best. Many people are told that your battery at full is 12.7v sitting and a 13.7 trickle will only charge about that high, however my batteries new showed 12.9v fully charged and I'm getting 13v true full charge with my solar by changing the default charge to 14.4v.
    The last 5% charge is important because it gives the highest amount of AH and helps to season your battery for best depth of storage hours.
    Some youtube how to vids recommend setting the default to 14.1v, others in forums have set theirs to 14.8v no problem.
    To be safe I used the parameters of a typical trickle charger and used the 14.4v figure and went from top charge of 12.6-12.7v to 12.9-13v true full charge.
     
  2. miketx
    Online

    miketx Diamond Member

    Joined:
    Dec 25, 2015
    Messages:
    49,405
    Thanks Received:
    5,428
    Trophy Points:
    1,870
    Ratings:
    +55,530
    A 12V car battery fully charged will read 12.66 volts. Each of the 6 cells produces 2.11 volts. It is normal for batteries full charged to show more than 12.66 volts because of something called "surface charge". To remove surface charge turn the lights on for 30 seconds, and turn them off and recheck it.
     
    • Winner Winner x 1
  3. Frankeneinstein
    Offline

    Frankeneinstein Gold Member

    Joined:
    Dec 7, 2016
    Messages:
    4,462
    Thanks Received:
    400
    Trophy Points:
    160
    Ratings:
    +2,789
    ok, I feel like I've reached the end of the internet
     
    • Funny and Agree!! Funny and Agree!! x 1
    • Informative Informative x 1
  4. miketx
    Online

    miketx Diamond Member

    Joined:
    Dec 25, 2015
    Messages:
    49,405
    Thanks Received:
    5,428
    Trophy Points:
    1,870
    Ratings:
    +55,530
    You are discharged,
     
  5. Frankeneinstein
    Offline

    Frankeneinstein Gold Member

    Joined:
    Dec 7, 2016
    Messages:
    4,462
    Thanks Received:
    400
    Trophy Points:
    160
    Ratings:
    +2,789
    lol
     
  6. HaShev
    Offline

    HaShev Gold Member

    Joined:
    Jun 19, 2009
    Messages:
    8,016
    Thanks Received:
    679
    Trophy Points:
    205
    Ratings:
    +2,972
    SPEAKING deep cycle battery grid at the turning on of any low wattage item a true full charge is reading 12.9v sometimes 12.8v. (*NOTE TEMPS AND .1V READING DIFFERENCES can be why it's higher)
    Regarding cars and car lights, that's dropping that much because it's slight surge & draining already.
    It's possible that my power inverter reads .1v higher since it does in comparison to my controler, however that does not change the fact that the battery is not being fully charged using solar on default controler settings.
     

Share This Page

Search tags for this page

azs