Sun Extender

65DegN65DegN Solar Expert Posts: 109 ✭✭
So what seems to be the consensus on these AGM batteries? I see some of you guys have these and I have a friend seriously considering some right now.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,230 admin
    Re: Sun Extender

    Have you looked at the delivered cost for both types of batteries?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Sun Extender

    i would also recommend adding another 25% to the ah bought as concorde does derate them in their manual by 25% for temp compensation above 77 degrees f.
  • Coach DadCoach Dad Solar Expert Posts: 154 ✭✭
    Re: Sun Extender

    Well... I'm far from an expert since I have ONLY been using mine for a month... But I have no complaints.
    The nice things are:
    - No Maintenance
    - No worries about outgassing causing corrosion and/or explosion
    - No 8 hr equalizing every month (I don't know how you would do that with PV anyway) My AGM's are set to Eq for 1 hr every 28 days (per concord)
    - No damage if frozen

    Besides the extra cost, I can't think of a reason not to use them.
  • BB.BB. Super Moderators, Administrators Posts: 32,230 admin
    Re: Sun Extender

    Generally, with AGM, the equalize voltage is just set to the absorb voltage (around 14.2-14.4 volts typically).

    Also, AGM's do out gas electrolyte fumes and hydrogen gas--It is just if they are over charged (such as a charge controller failure) or at end of life/failure--So, it is still a good idea to have them in a well ventilated area.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Sun Extender

    caution
    do not eq your batteries as a routine or you could damage them.
    concorde does not state that this is a routine to follow monthly, weekly or whenever. page 20 of their manual clearly states this is only to be done when there has been a capacity loss due to extended low charging (abused). i will go further and say that this should be done only when you believe the batteries are impaired due to age or heavy abuse, but never routinely.

    http://www.sunxtender.com/pdfs/Sun_Xtender_Battery_Technical_Manual.pdf

    as concorde says the conditioning (eq) voltage shall be 2.58v/cell at 77 degrees f. please understand that this will cause outgassing and will result in less capacity due to a permanent loss of electrolyte. as such you damage the batteries some in order to eq them.

    what bb described was an extended absorb charge and there is nothing wrong or harmful in doing this, even routinely as the voltage would not exceed normal battery settings and as such they will not outgas.
  • 65DegN65DegN Solar Expert Posts: 109 ✭✭
    Re: Sun Extender

    Thanks a lot for the information guys. BB, yes, I have checked the price and it is not that bad until the AH get above 300.
    I had a set of AGM batteries and they performed poorly but they were not Sun Extenders, which seem to be higher quality.
    I'll pass this along, thanks again.
  • SlappySlappy Solar Expert Posts: 251 ✭✭✭✭✭✭
    Re: Sun Extender

    Have 4 of the 8d for three yrs. Still going strong!
  • Coach DadCoach Dad Solar Expert Posts: 154 ✭✭
    Re: Sun Extender
    niel wrote: »
    caution
    do not eq your batteries as a routine or you could damage them.
    concorde does not state that this is a routine to follow monthly, weekly or whenever. page 20 of their manual clearly states this is only to be done when there has been a capacity loss due to extended low charging (abused). i will go further and say that this should be done only when you believe the batteries are impaired due to age or heavy abuse, but never routinely.

    http://www.sunxtender.com/pdfs/Sun_Xtender_Battery_Technical_Manual.pdf

    as concorde says the conditioning (eq) voltage shall be 2.58v/cell at 77 degrees f. please understand that this will cause outgassing and will result in less capacity due to a permanent loss of electrolyte. as such you damage the batteries some in order to eq them.

    what bb described was an extended absorb charge and there is nothing wrong or harmful in doing this, even routinely as the voltage would not exceed normal battery settings and as such they will not outgas.

    niel- The section of the manual that you are referring to says the condition it for 8 hours... so I can see what you mean.
    Attachment not found.

    However..... I had the EQ turned off for my system but Concord recommended that I turn it back on BUT do a 1 hour EQ every 28 days,,
    Do you think a 1 hour Eq will cause the same damage? What is your opinion of that advice?
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Sun Extender

    i wouldn't do that on mine, but who am i? think for a second as they warrant the batteries for 1yr. the batteries will easily last 1yr with abuse from eqing. many moons ago they did not even give an eq spec and that's because eqing could pop the vents. my recommendation would be an extended absorb charge if you don't suspect any problems with the batteries. one should exercise caution when you do go to do an eq charge and you should be there to listen for vents popping open. it wouldn't be real loud, but if you were to hear it then shut down the eq charging immediately. this does not save the day as some water escaped when it popped open.

    most needs of eqing are from inequalities between the batteries possibly due to connections, unequal wiring, or minor differences in the batteries which should not be if all were purchased new in the same batch. track the voltages now and then (every 1 to 3 months would be good) of the individual batteries during a rest period. if there's a consistent irregularity in the voltages then try switching a low battery (by voltage) with a high battery. if that battery slot still shows up low then suspect the wires or connections to that slot otherwise the switching could physically force an equalization.

    i need to do this for mine too as i'm long overdue.

    of course be sure the voltages are set correctly for charging in the first place. i try for the middle of the road on the charge voltage range. the extended absorb charge, should you opt for that should go to the charge voltage top end of 2.4v per cell and that's before temp compensation.
  • Coach DadCoach Dad Solar Expert Posts: 154 ✭✭
    Re: Sun Extender
    niel wrote: »
    i wouldn't do that on mine, but who am i? think for a second as they warrant the batteries for 1yr. the batteries will easily last 1yr with abuse from eqing. many moons ago they did not even give an eq spec and that's because eqing could pop the vents. my recommendation would be an extended absorb charge if you don't suspect any problems with the batteries. one should exercise caution when you do go to do an eq charge and you should be there to listen for vents popping open. it wouldn't be real loud, but if you were to hear it then shut down the eq charging immediately. this does not save the day as some water escaped when it popped open.

    most needs of eqing are from inequalities between the batteries possibly due to connections, unequal wiring, or minor differences in the batteries which should not be if all were purchased new in the same batch. track the voltages now and then (every 1 to 3 months would be good) of the individual batteries during a rest period. if there's a consistent irregularity in the voltages then try switching a low battery (by voltage) with a high battery. if that battery slot still shows up low then suspect the wires or connections to that slot otherwise the switching could physically force an equalization.

    i need to do this for mine too as i'm long overdue.

    of course be sure the voltages are set correctly for charging in the first place. i try for the middle of the road on the charge voltage range. the extended absorb charge, should you opt for that should go to the charge voltage top end of 2.4v per cell and that's before temp compensation.

    Thanks Niel... I will follow your advice... after all your batteries lasted 8 plus years.

    Another question for you if I may.... I've got my Absorb Voltage set to 28.6 Volts with Temp Compensation 0.06 from -30 to +80 Degrees F (as recommended by the Concorde Customer Service Rep)
    I've noticed that when the batteries are in Absorb, the charge controller is indicating a voltage of over 29 volts. (temps below 70F) is that normal? I was assuming that it had to do with the Temp Compensation.
  • Coach DadCoach Dad Solar Expert Posts: 154 ✭✭
    Re: Sun Extender
    65DegN wrote: »
    So what seems to be the consensus on these AGM batteries? I see some of you guys have these and I have a friend seriously considering some right now.

    Sorry 65DegN- I don't mean to hijack this thread with all my questions. I'm hoping that some of the replies will help you decide.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Sun Extender

    off topic it isn't as it is about sunxtenders, but i concur that i do not want to monopolize the thread with your (coachdads) concerns. i will say that i am confused by the .06 and you may have misunderstood them as i believe it is 4mv or .004v per degree c per cell. you may be overcompensating.
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