Off grid system - battery charger issue

ghostofthenorth
ghostofthenorth Registered Users Posts: 13 ✭✭
in Off Grid Solar & Battery Systems #1
Hello all, thanks in advance for the information.

I have an off-grid solar system consisting of:
~1000w solar panels
24v wet cells, 430Ah
Midnite classic charge controller

I have an inverter with an automatic transfer switch. I also just installed an aims power charger (12/24v auto sensing).

My issue is that the charger comes on when switched on, the lights show normal, the fan comes on, but after a few minutes (haven't timed it), it switches off.  Or more accurately, stops charging.  It's still on, LEDs are normal, but the fan turns off and it stops charging.

I can't sort out exactly why this is.  Is it possible the Midnite classic and the charger don't play nice?  If so, is there a way to notify the classic that the charger is on (so that only one charges at a time)?  Anything else I may be missing?

The charger is connected to the same earth ground as the classic.  They are both connected to the battery bank in parallel.  I also have a 24v fridge connected in parallel as well as the inverter.

Please help with any suggestions, I'd really like to get the charger working before I leave in a few days.

Ghost
Tagged:
· Share on Twitter

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #2
    What is the DC voltage at the battery bank?

    Exactly, which model of AIMS battery charger do you have?

    I would guess you are saying that the batteries are not fully charged? Is thei Midnite solar charge controller also charging at the same time?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • ghostofthenorth
    ghostofthenorth Registered Users Posts: 13 ✭✭
    #3
    I will check on the model number and post shortly, as well as the exact voltage.  I've been testing when the voltage is down, so not fully charged.  The batteries do not get fully charged yet the charger turns off.  The Midnite is also charging at the same time, yes.  Though I will try at night when the Midnite can't charge.
    · Share on Twitter
  • ghostofthenorth
    ghostofthenorth Registered Users Posts: 13 ✭✭
    #4
    The Aims Power charger is model CON120AC12/24VDC
    · Share on Twitter
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #5
    What is the battery voltage, when the AIMS shuts off?

    Try switching the PV input to the Classic, to OFF, or go into the Classic Mode screen on the MNGP display, and switch Mode to OFF, and see if the AIMS charger will charge.

    There is supposed to be a current adjustment for the AIMS charger, have you tried setting that?

    Thanks for the added info, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    edited June 2022 #6
    Looks like a standard battery charger with different charging profiles (lead acid, AGM, Li-Ion, etc.). This one?

    https://www.invertersupply.com/index.php?main_page=product_info&products_id=189717

    Assuming you have it setup correctly for your battery bank--I would pay close attention to the charging voltage at the battery bank (and at the DC output terminals of the charger--check for excessive voltage drop).

    If the Solar charge controller is set for a higher charging voltage than the AIMS, I could understand the AIMS would "stop charging" because its output charging voltage is lower than the Midnite charging voltage (when sun is up)... I.e., charging set to 28.8 VDC for AIMS and to 29.6 VDC for Midnite (as an example for common "absorb" voltage set points--AGM being around 28.8 VDC and flooded cell around 29.6 VDC).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • ghostofthenorth
    ghostofthenorth Registered Users Posts: 13 ✭✭
    #7
    Bill, that is the one, and yes it has standard charging profiles.  Vic, I had tried just that as well, switching off the classic with no change.  In fact the charger no longer attempts to charge.  Will be sending the charger back for diagnostics/repair.  It seems to be defective, just my luck!
    · Share on Twitter

Categories