When and how to "condition"my AGM batteries

Jebers12Jebers12 Registered Users Posts: 2
My LIFELINE AGM manual instructs to "condition" my batteries " when the battery is showing signs of capacity loss", and do so by charging, a fully charged battery, at 15.5 V ( temp. Compensated) for 8 hrs. Fine, but how can I tell when I'm experiencing capacity loss. Wondering if I have a capacity loss since my monitor is showing 85-89 % charged when my charger is going into float mode as per battery spec and monitor showing 14.5 V and only absorbing 1.1 amps(battery spec fully charged). My question is, do I have a " capacity loss" if my battery is fully charged when my monitor shows 85%? Trust the monitor is accurately tracking AH in and out, condition as per specs? Or is there another method to assess battery capacity? :confused:
My RV system:
2 roof top 150watt panels
Sunsaver 15 MPPT controller
Trimetric 2025 RV monitor
2 6v 220ah (series) lifeline AGM

Comments

  • westbranchwestbranch Solar Expert Posts: 5,142 ✭✭✭✭
    Re: When and how to "condition"my AGM batteries

    Have you spoken to your battery dealer? That sounds like an EQ to me.

    read this document to understand what is happening in that battery while being charged.

    http://www.cdtechno.com/pdf/ref/41_2128_0212.pdf
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: When and how to "condition"my AGM batteries

    battery monitors are not always accurate so i would not suspect the batteries. only way to be sure is to load test the batteries.
  • Coach DadCoach Dad Solar Expert Posts: 147 ✭✭
    Re: When and how to "condition"my AGM batteries
    Jebers12 wrote: »
    My LIFELINE AGM manual instructs to "condition" my batteries " when the battery is showing signs of capacity loss", and do so by charging, a fully charged battery, at 15.5 V ( temp. Compensated) for 8 hrs. Fine, but how can I tell when I'm experiencing capacity loss. Wondering if I have a capacity loss since my monitor is showing 85-89 % charged when my charger is going into float mode as per battery spec and monitor showing 14.5 V and only absorbing 1.1 amps(battery spec fully charged). My question is, do I have a " capacity loss" if my battery is fully charged when my monitor shows 85%? Trust the monitor is accurately tracking AH in and out, condition as per specs? Or is there another method to assess battery capacity? :confused:
    My RV system:
    2 roof top 150watt panels
    Sunsaver 15 MPPT controller
    Trimetric 2025 RV monitor
    2 6v 220ah (series) lifeline AGM

    Hmmm... If you are loosing capacity, I would expect that the batteries become discharged quickly but still go up to 100% SOC when fully charged. I wonder if your battery monitor lost track of the ah in and out.
    I would reboot the battery monitor and see if the problem goes away. Did you set your battery monitor for a 220ah battery?
  • Jebers12Jebers12 Registered Users Posts: 2
    Re: When and how to "condition"my AGM batteries

    Thanks for the input folks. Aye, when batteries new i programed monitor for ah capacity ...Discharge ( according to monitor % full) seemed accurate, but charge seemed" stuck" around 80-89%. Well, yesterday while out hiking, % full went from 72-100%!!!! That would be 60+ ah in 6 hours while the panels are pulling in 5-6 amps, the math doesn't work! Alli I can figure is somehow the monitor reset itself? Anyone else have this experience with their monitor?
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: When and how to "condition"my AGM batteries

    What you really need to do is get a baseline load test. I usually do it when the Batteries are new during commissioning. I take a known load, ( say a Microwave Oven, space heater, hair dryer or similar ) I record the amp draw and how long it's on and the Voltage drop low point. From that data you always have a constant to try to return to. Since you probably don't have that and your batteries are sealed, you can create one. Take a known load and get the data points. Then you can condition ( EQ ) batteries a hour at a time and see if the base data ( Low Voltage drop ) gets better. Your batteries are one of the few the Manufacturer recommends doing it to, but I have done the same to other sealed batteries with success. 8 Hours @ 15.5 Volts in the dark without knowing where you are and where your going is crazy.

    Your Battery Monitor is probably not accurate, most never are, just a false sense of security.
    .
  • Coach DadCoach Dad Solar Expert Posts: 147 ✭✭
    Re: When and how to "condition"my AGM batteries
    Jebers12 wrote: »
    Thanks for the input folks. Aye, when batteries new i programed monitor for ah capacity ...Discharge ( according to monitor % full) seemed accurate, but charge seemed" stuck" around 80-89%. Well, yesterday while out hiking, % full went from 72-100%!!!! That would be 60+ ah in 6 hours while the panels are pulling in 5-6 amps, the math doesn't work! Alli I can figure is somehow the monitor reset itself? Anyone else have this experience with their monitor?

    I don't understand your calculations.
    You have 300 Watts of panels... Estimate= 300W/14.3V = 21A X .7% efficiency = 14.7A out of your MPPT..
  • ThomasThomas Solar Expert Posts: 291
    Re: When and how to "condition"my AGM batteries

    You wont know when there is a decay in functionality until you have stood at the top of the giants shoulders off grid on battery power and they cycle, like finishing your lawn on empty....I havent expirienced this yet though I am waiting. Then recharge, when they stop doing this, condition them, for some more off grid time. I do not think a digital read out will indicate a state of charge problem. I haven't experienced this yet, though I am building to it.
    Always troubleshoot with adequate sunlight.  Hi Ho Hi Ho
    2.3kW [10] Enecsys SMI-240-60 micro inverters

  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: When and how to "condition"my AGM batteries

    You are undercharging those agm's and reducing their capacity every cycle. So your instincts are correct.

    Lifelines require a *minimum* of 0.2C charge current, and in your case, that amounts to about 44 amps during bulk.

    You'll need to at least triple the panel capacity you have now, and in the meantime, try to save those batteries with an ac charger like an Iota DLS-45 OR larger. I wouldn't equalize them just yet as long as you put them through several normal cycles on a 44a minimum charger and see where you stand.

    From a solar perspective, the nearly 1kw array you'll need doesn't factor into account your specific solar-insolation to actually achieve a full charge, and only takes into account the minimum amount of current needed. Depending on solar insolation and depth of discharge, you may actually need much more. Fortunately, the Lifelines can handle large amounts of input current, but the minimum of 0.2C should be met on a regular basis.
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