charge controller skipping acceptance stage

landyacht.318landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
Kyocera 130tm
blue sky sb 2512i controller with ipn pro remote battery monitor
3 115 ah wally world ever start quasi deep cycles.

This system is installed in a Camper Van.

I realise I have more battery than solar to charge them and was wondering if this could cause the controller to skip the acceptance stage and go right to float. Well it does go into acceptance, for about 3 seconds. The monitor will read 6 amp hours from full and 97 or 98% and then go right to 100% and 0 amp hours from full.

I just returned fom a 10 week stay in Baja and the system, according to the monitor never dropped below 82%. Rarely did I even tilt the panel and just left it flat as float mode was kicking in by mid morning depending on how loud and long I played the stereo the night before.

It seemed to make no difference to the acceptance stage if I'd isolate the engine battery from the charge controller.

I tried lowering the acceptance voltage to 13.7. The acceptance time is set for 2 hours. No difference.

When the engine is running with the batteries above 90% the alternator amperage will be between 8 and 20 and then the charge controller says it is in acceptance mode, but the battery monitor says there is only .1 amps flowing into the batteries from the PV.

Any insight to this situation is much appreciated.

Comments

  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    I am thinking about suphation.
    How old is the battery?

    Eric
     
    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
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    13.7 V is too low for acceptance. It should be 14.4 V (ref 77 F battery temperature) for your battery bank.

    Take a look at these excerpts from the 2512i(x) manual:
    [FONT=&quot]Acceptance Charge[/FONT]
    As the battery charges in Bulk, battery voltage slowly rises as the battery recovers charge. When sufficient charge has been recovered for battery voltage to reach the Acceptance voltage setpoint, the unit changes to a constant voltage mode where the Acceptance voltage is applied to the battery. The Acceptance voltage is factory set to 14.4V. In Acceptance the battery is typically between 70% to 95% charged depending on battery size and available charge current. The battery remains at the Acceptance voltage until fully charged and the unit switches to Float as determined by either;

    1. Battery voltage has been continuously at (or above) the Acceptance voltage setpoint for the Charge Time period.
    (factory default = 2 hours)

    – OR –

    2. With the IPN-ProRemote display, net battery charge current drops below the Float Transition Current setting
    (factory default = 1.5A per 100 amp-hours) while the battery is at (or above) the Acceptance voltage setpoint.

    [FONT=&quot]Float Charge[/FONT]
    Once the battery is fully charged the unit switches to Float where the Float voltage is applied to the battery to maintain it in a fully charged state without excessive water loss. The Float voltage is factory set to 13.2V. During Float a healthy fully charged lead-acid battery will draw approximately 0.1–0.2 amps per 100 amp-hours of battery capacity.

    [FONT=&quot]TWO STAGE CHARGE CONTROL[/FONT]
    Certain battery types or system configurations may require two stage charge control. Solar Boost 2512i(X) can be configured for two stage charge to accommodate these batteries or systems. Two stage charge is selected by setting the Float charge voltage setting to No Float using the IPN-ProRemote. Refer to the IPN-ProRemote operators manual to configure two stage charge.
    HTH,
    Jim / crewzer
  • landyacht.318landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    Thanks for the info.
    As the battery bank is less than 6 months old and rarely ever been discharged below 20% dod I have to assume that my 130 watt panel is incapable of bringing up the 2 or three batteries upto the 14.4 volt threshold. The highest I've seen it go by the pv system is 14.2, where I had the acceptance charge set at the time.

    Crewzer, if I were to set my controller into the no float mode would I have to worry about my 130 watt panel overcharging 345 a/h of batteries?
    Am I still unlikely to get to acceptance voltage having more battery than panel?
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    3 wally world 115ah batteries will present a total of 345ah and 7.39a is a bit low to charge all 3 at a 2.14% rate.
    as to the float you can leave it there, but do readjust the acceptance voltage point as crewzer specified to 14.4v. you have been undercharging them with an acceptance setting of 13.7v and you have a low charging current to begin with. i recommend that after you have reset the acceptance voltage to where it belongs to allow the batteries to charge without any loads to them until they have gone through to float. if after a few days you find them not reaching float then try to charge the batteries individually and don't drain any power from them until all are brought up to snuff. another pv would help tremendously too.
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    Am I still unlikely to get to acceptance voltage having more battery than panel?
    Landyacht,

    I’m having trouble understanding your question. Your intial post indicated that your system was reaching acceptance voltage level, just not for very long. Was it reaching 14.4 V, or just 13.7 V?

    When your RV is in use, the 130 W module will most likely have trouble driving your 12 V x 345 Ah battery bank to the target acceptance voltage. Shading and alignment will also affect performance.

    However, if when the RV is parked and there’s very little or no load on the batteries, the PV module should be able to charge and maintain the batteries. That’s assuming sufficient Sun and good module alignment, of course. I used a single 40 W module to charge and maintain my deck-light system’s old Interstate SRM-27 battery for almost 5 years, and the battery was two years old when that project started. I just replaced the -27 with a new SRM-29, and it appears to be working fine.

    HTH,
    Jim / crewzer
  • landyacht.318landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    Crewzer,
    It will not stay in acceptance longer than 5 seconds with the acc. voltage set to 13.7, 14.2 or 14.7.

    I have not needed any more panel, 130 watts has been more than enough for my requirements, and the 3 batteries, although unmatched to my panel are not going anywhere, I like having the backup capacity.

    I wonder If I could fool the controller by setting the float current and voltage to the acceptance values.
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    My gut feel is that the problem lies with the "Acceptance Charge" discussion above. At 1.5 A per 100 Ah, the charger may be expecting to see >~5 A going to the batteries. With a Vmp of ~7 A or so, I doubt the one PV module is supplying > 5A under most conditions, especially in the afternoon. The controller may be deciding the batteries are full due to the low charge current, and that could well be causing it to prematurely terminate the acceptance charge.

    Try dropping the parameter to 0.5 A per 100 Ah and see what happens.

    HTH,
    Jim / crewzer
  • landyacht.318landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    I can adjust the acceptance voltage and time in acceptance but not the current. I did just set the float voltage at .5 amp/100 ah. I'll see what happens.

    Recently when in Baja, and not moving the van for days on end it would switchfrom bulk to float between 10 and 12:30 on the bright days. At those times the monitor would indicate output, in bulk stage, between 4.5 and 7.8 amps with the panel flat on the roof. I did notice that the few times I did tilt the panel after a 3 or 4 foggy day stretch, it did stay in acceptance for a minute or 2 before switching over to float.
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: charge controller skipping acceptance stage
    I did just set the float voltage at .5 amp/100 ah.
    That's what I meant. Assuming battery capacity is programmed at ~345 Ah, the acceptance-to-float transition current should be ~1.7 A.

    Here's hoping for some good news! :cool:
    Jim / crewzer
  • landyacht.318landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    I've set the amp hours to 230 because I will sometimes Isolate the engine battery overnight If I plan to start the van early or If I expect cloudy weather for a few days. I have not noticed any difference in performance when doing this. The battery percentage just drops off faster. Should I leave it at 345?

    After starting the van on the isolated battery I'll move the switch to both and watch the alternator amperage go from ~11 to ~45, and the engine note will change with the added load.

    All the batteries are of the same make and age. The engine is connected to the house bank over 12 feet of 2 awg cable through a boat 1/2/both/OFF switch.
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    It’s probably better to set the battery capacity at 230 Ah and occasionally add a chassis battery rather than set the capacity at 345 Ah but usually only have two house batteries connected. Let’s see how the new float transition setting works out (0.5 A / 100 Ah x 230 Ah = 1.15 A).

    The ammeter jump for 11 A to 45 A when you connect in the two house batteries probably means that ~34 A is going to those two batteries. Should be OK, but keep an eye on the electrolyte levels.

    HTH,
    Jim / crewzer
  • landyacht.318landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    Yesterday provided enough sunlight to prove the .5/100 a/h float current has worked. It now goes into acceptance with 2 batteries connected. If I change the boat switch to both, bringing the engine compartment battery in the mix, the voltage drops and it falls back into bulk.

    With only 2 batteries connected, the 2.7 a/h fridge switching on will drop it back to bulk mode as well. I don't know if this resets the 2 hour acceptance time I've currently have set.

    Yesterday, it did not go into float mode, although it did indicate 100% and 0 amp hours from full. The sun was obscured at this point.

    Thanks for the help!
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    8)

    Travel safe!
    Jim / crewzer
  • landyacht.318landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    Update:
    During the last 2 fully sunny days it went into 14.4v Acceptance at 10:30 until 12:30pm and 13.2v Float till an hour before sundown, with all 3 batteries hooked in parallel. Even with the fridge compressor running, it stayed in acceptance or float. My panel is currently flat on my roof, leaning away from due south.
    Thanks again.
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: charge controller skipping acceptance stage

    Great news! :cool:

    Thanks for the feedback,
    Jim / crewzer
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