talk me through charging batteries ... (need bulk charging voltage)

al128
al128 Solar Expert Posts: 65 ✭✭✭✭
hi there,

I recently bought a used deep cycle battery for very cheap. The producer's site is down, the producer out of business - so no way to get further information from the horse's mouth.


Here are some facts concerning the batt:

- 12V 100ah
- lead acid (maintainance free w/o access to electrolyte)
- recommended floating voltage 13.7V (says label)
- the batt. is visually pretty new, measured 12.6V when I got it, and 12.9V after a day of charging
- my charger is a xantrex c12 (charger/lighting thingy) that allows setting the charging voltages



based on this information, what value would you set your bulk charging voltage (in the charger)???


thx,
al

Comments

  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    Re: talk me through charging batteries ... (need bulk charging voltage)

    Sounds like a typical lead-calcium marine battery.

    Bulk setting is 14.3v to 14.5 vdc.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: talk me through charging batteries ... (need bulk charging voltage)

    I suggest you read some of the following: http://www.batteryfaq.org/
    http://www.batteryfaq.org/

    Tony
  • GreenPowerManiac
    GreenPowerManiac Solar Expert Posts: 453 ✭✭✭
    Re: talk me through charging batteries ... (need bulk charging voltage)

    Al,

    Sounds like my SLA's. I have a Morningstar Ts-60 charge controller and it's set at 14.0 volts to bulk charge. Gel type batteries should be charged at no more than 14.1 volts and the slower the better.

    If your battery floats at 12.9v then I would suggest a few more days of no-load charging to see if it increases. If not, it could be partially sulfated. Does your charger have PWM (Pulse Width Modulation) ? Mine does and will PWM when it reaches floating charge and desulfate the plates clean over a few days, thus raising the charge level back to optimum.
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  • al128
    al128 Solar Expert Posts: 65 ✭✭✭✭
    Re: talk me through charging batteries ... (need bulk charging voltage)
    Al,

    Sounds like my SLA's. I have a Morningstar Ts-60 charge controller and it's set at 14.0 volts to bulk charge. Gel type batteries should be charged at no more than 14.1 volts and the slower the better.

    If your battery floats at 12.9v then I would suggest a few more days of no-load charging to see if it increases. If not, it could be partially sulfated. Does your charger have PWM (Pulse Width Modulation) ? Mine does and will PWM when it reaches floating charge and desulfate the plates clean over a few days, thus raising the charge level back to optimum.

    the c12 is a pwm charger ... the bat. came in at 12.9V after a mostly cloudy day, w/ just a 75w panel hooked up (4.5 amps? at 17V) ... I doubt I really reached bulk voltage to go into absorption ...


    why is it that whenever i buy a bat. we get a week's worth of clouds and rain :-/


    I currently run them at 14.4v bulk and 13.6v float ... what are things I should keep an eye on over the next few days in order to determine how healty this puppy is?

    thx, again
    al
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: talk me through charging batteries ... (need bulk charging voltage)

    i have to ask you if that 12.9v you measured was after allowing the battery to rest for 2-3 hours with no loads or charging current? this is termed at rest voltage. if so, it sounds like it reached full charge to me. 12.6v is not that terribly far down so it is possible you charged it. 14.4v is quite common for many batteries to charge with and there are exceptions, but based on the higher float voltage i don't think there's a need to go lower than 14.4v bulk voltage unless you suspect it to be a gel battery. i wonder if the auto eq charge can be disabled on it as you won't need that for 1 battery.
  • al128
    al128 Solar Expert Posts: 65 ✭✭✭✭
    Re: talk me through charging batteries ... (need bulk charging voltage)
    niel wrote: »
    i have to ask you if that 12.9v you measured was after allowing the battery to rest for 2-3 hours with no loads or charging current? this is termed at rest voltage. if so, it sounds like it reached full charge to me. 12.6v is not that terribly far down so it is possible you charged it. 14.4v is quite common for many batteries to charge with and there are exceptions, but based on the higher float voltage i don't think there's a need to go lower than 14.4v bulk voltage unless you suspect it to be a gel battery. i wonder if the auto eq charge can be disabled on it as you won't need that for 1 battery.


    I measured after dark, so likely 1-2 hours after charging ended ...

    day 1 ( after dark) 12.9V
    day 2 (after dark) 13.2V


    and yes, i disabled the automatic EQ charge since I cant access the cells ...

    how would I find out if its a gel battery? ... shaking it and not hearing fluids slushing i guess ... right?

    again, thx
    al
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: talk me through charging batteries ... (need bulk charging voltage)
    al128 wrote: »
    how would I find out if its a gel battery? ... shaking it and not hearing fluids slushing i guess ... right?

    again, thx
    al

    Are there removable caps on the top ? If no caps, either GEL or AGM

    Mfg and model # will give a good clue
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  • al128
    al128 Solar Expert Posts: 65 ✭✭✭✭
    Re: talk me through charging batteries ... (need bulk charging voltage)
    mike90045 wrote: »
    Are there removable caps on the top ? If no caps, either GEL or AGM

    Mfg and model # will give a good clue

    no caps, as its a maintainance free bat...

    but then again, my Honda Civic's battery is maintainance free but surely not GEL or AGM :confused: