AGM float setting

SystemSystem adminPosts: 2,511 admin
uh oh, I might have screwed up here. On the DEKA site for these 8A8DM 245 amp hour batteries the only charge info is "charge at least 14.4 volts but no more than 14.6 volts. no mention of a float setting. the mx60 defaults to 14.4 absorb voltage so I figured I was good. now I see that in the back of the mx60 manual it suggests an AGM float setting of 13.4 volts while the unit defaults to 13.6 volts. the four 8D's are in parallel and live in a hot hot climate.an RTS is in use. I understand the worst thing for these AGM's is overcharging. did I do that???

Comments

  • BrockBrock ✭✭✭✭ Solar Expert Posts: 633 ✭✭✭✭
    Re: AGM float setting

    I am not sure I understand what you’re asking, but I stick to 14.4 as absorb and 13.3 as float on my Deka 8A8D's. The big catch is to not go above the 14.6, never, never equalize them, that would be bad...

    If what your asking is did floating them at 13.6 hurt them I would put money on no, again the main goal is stay below 14.6.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • System2System2 admin Posts: 6,290 admin
    Re: AGM float setting

    thanks brock. I'll be visiting these 8D's in a couple weeks and will lower the float setting. did you arrive at the 13.3 float setting from deka? thanks,mark
  • nielniel ✭✭✭✭ Solar Expert Posts: 10,311 ✭✭✭✭
    Re: AGM float setting

    doing that longterm may have a small effect if it managed to gas some, but by all means lower the float point asap. i also doubt any real harm has come to your batteries, but i can't say for sure.
  • BrockBrock ✭✭✭✭ Solar Expert Posts: 633 ✭✭✭✭
    Re: AGM float setting

    Not really I think Jim (Crewzer) had said once it was 14.4 and 13.4 per 12v. I don't know how I started with 13.3 the three must have just stuck. I am now running eight 8A8D's in a 48v setup so I am at 57.6 absorb and 53.2 float
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • BB.BB. admin Super Moderators, Administrators Posts: 29,634 admin
    Re: AGM float setting

    Also, remember these numbers need to be temperature corrected--ideally with a charge controller that has a remote battery temperature sensor. If the batteries are colder than ~77F, the voltage requirements will go up; if over 77F, the voltage requirements go down.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel ✭✭✭✭ Solar Expert Posts: 10,311 ✭✭✭✭
    Re: AGM float setting

    brock,
    i'm not sure of the proper voltages for the deka batteries, but 13.6v float is higher than it should be as both 13.3v and 13.4v are both lower. i'd assume jim would get it right as he owns those batteries too or maybe you could be remembering wrong. in any case, unless the long term use of that 13.6v had caused gassing then as i said then i doubt any damage had occured. i'm not even sure if that long term higher voltage could cause it to gas. i guess deka might know if it would, but it is always good to follow the recommendations of the manufacturer for best life and performance and as bb said being temperature compensated.
  • n3qikn3qik ✭✭ Solar Expert Posts: 741 ✭✭
    Re: AGM float setting

    Down load this and go to the bottom of page 11. There is the chart for charge/float voltages for AGM batteries.

    http://www.eastpenn-deka.com/assets/base/0139.pdf
  • nielniel ✭✭✭✭ Solar Expert Posts: 10,311 ✭✭✭✭
    Re: AGM float setting

    by the link provided by ken it looks like you're ok as long as you are using the bts.
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