Sunsaver MPPT staying in absorb?

BrockBrock Solar Expert Posts: 632 ✭✭✭✭
At first I just thought my battery was low, but the Morningstar Sunsaver MPPT has never come out of absorb.

Right now I only have the 12v battery hooked up on the battery side and on the solar side I have it connected to the 48v battery bank (usually sits between 50v and 56v). I tried disconnecting everything and reconnecting it, but it never seems to stop absorbing. From what I understand from the manual it should only stay in absorb for 3 hours, but twice I let it sit overnight thinking the battery was just low and it never came out of absorb with the battery voltage sitting about 14.4v the entire time. I have the dit switches in 1=on, 2=off, 3=on and 4=off and the jumper out, but nothing connected to the "load" side. The battery is sitting with no load on it either.

Thoughts?
3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI

Comments

  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Sunsaver MPPT staying in absorb?

    Correction:

    According to Solar Guppy the Morningstar MPPT controllers do in fact have a built in current limit.

    If you connected it directly battery to battery, it is possible you blew out the controller from too much surge amperage. Most controllers have no current limit except what the solar panel can put out. And the limit on a 48 volt battery is hundreds of amps.
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    I have used the Sunsaver MPPT alot and have never had a problem with one yet.

    Has this setup been working correctly and going into float before and now its not going into float as usual?

    Is there any load on the battery while it charging? That will cause it to not go into float mode.

    Is this a new setup? How old is the battery?

    Also you meant that you are connecting to a 50+V Solar Panel Array not Battery Bank Correct?
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    the controller should not have burned out as they do limit the output current to 15a. recheck your wiring and if all else fails contact morningstar.
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    What is the units criteria for exiting absorb. Two usual criteria are current dropping to a programmed point or time expiring.

    Sometimes when the charge rate is too low for the battery size it never reaches the low current termination. An old battery or battery suffering from too much overcharging can have high leakage and might not reach termination current. This is why there should be a failsafe time limit termination.

    I am not familar with Sunsaver but you should be able to check these in the user manual.
  • BrockBrock Solar Expert Posts: 632 ✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    I will put a nice size resistor in line with the input side and see what that does. That is what I was thinking that when the solar does start it slowly comes on where the battery bank is an instant on and that might be confusing it?

    I did think of the battery and the loads. The battery could be bad, it is about 3 years old and just a marine battery, but I tried a regular deltran charger and it came up to voltage rather quickly and went in to float, so I think I can rule the battery out. I also took all the loads off thinking they could be causing the controller to think the battery voltage was lower than it really was.

    niel I was thinking like you were since the controller was self limiting it shouldn't matter, but now that windsun said that inrush current could somehow damage it, I am worried. I had no idea this setup might damage it. I do have a 7.5 amp fuse on both side of the "solar" input and neither of them has failed. The first time I hooked it up it did go in to float, then I was re-routing some wires and re-connected it and since it won't go in to float.

    I will try putting a 100w lamp in series with the battery on connection and then remove the lamp and see what that does.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • loreleclorelec Solar Expert Posts: 200 ✭✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    I'm with Windsun on this one. I would never use a battery as the source on a controller that is designed for solar. Unless the controller's current limiting acts on a cycle-by-cycle basis, it might not respond fast enough to prevent damage. You have a virtually unlimited source of current (for all practical purposes) there in your 48v battery, and a very heavy sink in your 12v battery.

    It's also possible that the controller just doesn't know how to react to your setup? Try using it with a solar panel...that should tell you if you broke it.

    Marc
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,420 ✭✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    Current limit the input and make sure that the output is connected FIRST.
    Of coarse this is too late now... Hope I am wrong but it is kind of a standard way to do this kind of thing!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • mike95490mike95490 Solar Expert Posts: 8,235 ✭✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    disconnect it all, and let sit 10 minutes, then connect the 12V battery up, this will power up and configure the controller, then, with a sensible limit (resistor, light bulb, whatever) apply the charge voltage via the limit device. if the limit device is too "restrictive" parallel it with another one.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    what resistance are you placing inline with it as this could be too high of power for the resistor to take depending on its ohms and wattage rating?
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    We took a look at this and found something interesting ... it appears there is a bug in the SunSaver Mppt's code that when its first powered on it goes into absorb state, then 3 hours later float but the LED's indicate it still in Absorb. On the next cycle on the PV input it will work fine from then on.

    For this application, I would suggest connecting the SSMPPT to the 12V battery, flip your breaker or disconnect on for the PV side, let it run for a few minutes, then open the PV side for a few minutes then reconnect. this will cycle as a new day for the controller and from then on all should work as expected.

    To cover some of the question raised in this thread;

    It perfectly OK to have the SunSaver Mppt act as a step down converter , as the OP is doing a 48V to 12V battery bank. No resistors, light bulbs or other devices need to be put in series on the PV input side

    The Unit will self regulate to it current limit, it is proper safety to have a fuses to protect the wiring.

    The SSMPPT has excellent DC regulation, We have tried this with some other Major brands and found they don't respond fast enough for proper over current when the PV side is a battery or other near unlimited DC source.

    It always surprised me how people find alternative ways to use these chargers and this time found a bug I missed in my testing 2 years ago. I did extensive logging using SC-View which showed proper operation, its just the LED state thats got the start-up bug, we doubled checked and the 3 hour time for the Absorb -> float transition works as documented.

    This will be addressed in the next release, which is planned for March-April time frame which also will have new features for lighting control on the load output. Firmware for all MorningStars products are offered on the company website.

    Hope this help answers some questions

    SG
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    SolarGuppy - since your hear and have worked with the Sunsaver MPPT I have some questions for you. I have installed about 10 of these Sunsaver MPPT's on different portable solar power systems.

    What happens if you input over 200W? I know it just limits the output to 15A but what if i put 300W worth of Solar Panels on it? At what point does the unit shut off the output vs just limit the current to 15A of Output?

    Also from what you just said I get that you can use other DC Sources on the Solar Input, like regular Batteries that have a voltage above the voltage of the battery bank you are trying to charge. Anything other than Batteries that are safe to use like this? Very interesting. This could allow us to use different smaller chargers to recharge the battery packs exactly how we want them charged via our programmed charging setpoints.

    Also good to know about the LED Error when the Sunsaver is first power up.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    The SunSaver Mppt has no limit on the input array size, a battery is as close to unlimited as one can get for amps and it work fine. So no worry's if you should choose to use as in your example a 300 watt panel, which would make sense for hot climates where you need the 15 amps output but deal with it being cold safely.

    Since the SunSaver Mppt is powered from the battery, you have to have some battery, not just a load for proper operation. As long as its with the units specified voltage range your good to go

    Please understand, the above is ONLY for MorningStar Mppts units ( both Sunsaver and TriStar ), other manufactures charge controllers may not be safe in these conditions
  • BrockBrock Solar Expert Posts: 632 ✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    Thanks SG! The funny thing was the last time I checked the battery voltage was lower, at float voltage, and I thought I fried the battery since the controller still said it was still in absorb.

    I will go reset it and I am relieved I didn't fry it!
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • BrockBrock Solar Expert Posts: 632 ✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    I turned it back on and then disconnected the "solar" side for 5 minutes then reconnected the solar side. It went in to absorb for some time and has been sitting in float ever since.

    SG should I occasionally disconnect he input side to let the controller see a "new day" or is there no reason to do that?

    Thanks again!
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Sunsaver MPPT staying in absorb?
    To cover some of the question raised in this thread;

    It perfectly OK to have the SunSaver Mppt act as a step down converter , as the OP is doing a 48V to 12V battery bank. No resistors, light bulbs or other devices need to be put in series on the PV input side

    The Unit will self regulate to it current limit, it is proper safety to have a fuses to protect the wiring.

    SG

    That is good to know. The manual is not real clear about that, so we have been recommending not to do it, since most controllers have little or no protection against overcurrent if the source can supply more than the controller can handle.
    RWB wrote: »
    Also from what you just said I get that you can use other DC Sources on the Solar Input, like regular Batteries that have a voltage above the voltage of the battery bank you are trying to charge. Anything other than Batteries that are safe to use like this? Very interesting. This could allow us to use different smaller chargers to recharge the battery packs exactly how we want them charged via our programmed charging setpoints.
    We also have use at times for dual voltage systems, especially in cell phone and similar sites where part runs from 48 volts but 12 or 24 volts is also needed.

    This sounds like a very handy feature, I wonder why Morningstar does not make this a bit more clear in their literature. It sounds to me like we could use something like a 60 amp for the main system and the 15 to step down to an aux battery.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: Sunsaver MPPT staying in absorb?
    Brock wrote: »
    I turned it back on and then disconnected the "solar" side for 5 minutes then reconnected the solar side. It went in to absorb for some time and has been sitting in float ever since.

    SG should I occasionally disconnect he input side to let the controller see a "new day" or is there no reason to do that?

    Thanks again!

    Your call ... The SunSaver will only go back to bulk if your battery voltage reaches the rebulk set point, otherwise, it will float forever without disconnecting the PV side. If you cycle the PV side, it will go cycle through the Charging States
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,420 ✭✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    Following up on this I have a question. What would be the idle power loss be of using a 24V water pump as a load for a 48V bank? Is is a dream?
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • lamplightlamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    i found this thread because i noticed my new tristart mppt60 was in absorb for 300+ minutes yesterday and was doing the same thing today. it worked fine for a few days, absorbing and going into float. i power cycled the tristar (both input and output) but did not wait a full 5 or 10 minutes (before i found this thread), maybe 1 minute, and started it back up. from the looks of the logs its got a time set point of 3 hours, and its only been absorbing (again) for 120 so we'll see. hmm.. this is disappointing to find this bug. looks like the same code probably used as the controller you have brock as it sounds like the exact same problem.
  • lamplightlamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: Sunsaver MPPT staying in absorb?

    well, its did get to float today.. i guess the power cycling did the trick. i am going to see if there are any firmware updates I suppose.
  • CraigCCraigC Registered Users Posts: 16
    Re: Sunsaver MPPT staying in absorb?
    lamplight wrote: »
    well, its did get to float today.. i guess the power cycling did the trick. i am going to see if there are any firmware updates I suppose.

    Did you find out the cause of the non-float?
  • sanitariusanitariu Solar Expert Posts: 33 ✭✭
    Re: Sunsaver MPPT staying in absorb?

    I think i have the same bug. Morningstar MPPT 45A.
    Some days staying in absorption for 6-7 hours !!!
    My battery is setup as custom. I put 120 minutes only absorption but it does not work.
    Any one with solution ?
    4 X 240watt Luxor, Victron Energy Multiplus Compact 24 volt 1200VA, electrodacus solar controller, 8 x WB-LYP160AHA LiFeYPO4 3.2volt
  • BB.BB. Super Moderators, Administrators Posts: 28,998 admin
    Re: Sunsaver MPPT staying in absorb?

    I think you will need to call MorningStar support for help... You could try rebooting the controller (turning off/disconnecting all power for a minute or so--Solar array and battery bank, then reconnect the battery first, and then the solar array second.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sanitariusanitariu Solar Expert Posts: 33 ✭✭
    Re: Sunsaver MPPT staying in absorb?

    I already did.
    The answer is:
    "Hello,
    Please use MSView to disable the Float Cancel feature as well. This should reduce the absorption time."

    May be some bug connected with Float Cancel feature ?!
    But if i disable float cancel will the controller stay in float forever ?
    4 X 240watt Luxor, Victron Energy Multiplus Compact 24 volt 1200VA, electrodacus solar controller, 8 x WB-LYP160AHA LiFeYPO4 3.2volt
  • BB.BB. Super Moderators, Administrators Posts: 28,998 admin
    Re: Sunsaver MPPT staying in absorb?

    Is this a Battery to Battery charging setup (instead of solar panel to battery)?

    There was a bug in reporting absorb forever:

    http://www.morningstarcorp.com/en/support/item.cfm?ItemId=453
    Sep 4, 2012: fixed bug where controller would always report absorption stage when charging one battery with another battery.

    A few years ago, I thought I remembered a known problem with some models of MorningStar controllers and over charging a battery bank--But I cannot find any related posts. :confused::confused:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sanitariusanitariu Solar Expert Posts: 33 ✭✭
    Re: Sunsaver MPPT staying in absorb?

    This may help owners of "Sunsaver MPPT" model.
    I am using Tristar MPPT 45a .
    Will see today and if stays again for 6 hours in absorption I will cancel float or reset the controller.
    4 X 240watt Luxor, Victron Energy Multiplus Compact 24 volt 1200VA, electrodacus solar controller, 8 x WB-LYP160AHA LiFeYPO4 3.2volt
  • dkpro1dkpro1 Registered Users Posts: 23
    Re: Sunsaver MPPT staying in absorb?
    sanitariu wrote: »
    This may help owners of "Sunsaver MPPT" model.
    I am using Tristar MPPT 45a .
    Will see today and if stays again for 6 hours in absorption I will cancel float or reset the controller.

    You have to hook controler to a lap top and disable the float cancel I had to do this
  • JLFHJLFH Registered Users Posts: 6 ✭✭
    I want to use a 48v battery bank as "solar" input to a SunSaver MPPT 15L charging a 24v battery bank, have anyone try this succesfully?
  • mike95490mike95490 Solar Expert Posts: 8,235 ✭✭✭✭✭
    I've not tried it, and I think I recall the sunsaver should be OK up to 30V or so. 
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BrockBrock Solar Expert Posts: 632 ✭✭✭✭
    Yes this works, every since I figured out you have to cycle it the first time (or any time it is disconnected from everything) it has been fine and working for 8 years now  :)
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • JLFHJLFH Registered Users Posts: 6 ✭✭
    I found this video on YouTube about it:


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