FM80 snoozing when it shouldn't

706jim

I've owned an Outback FM80 for about three months. Initially it worked perfectly. Recently it has decided to go into snoozing mode in the middle of the day with the batteries are partway through the bulk cycle. Batteries are not overheated, plenty of sun. My settings for 24 volt system are 27.6 float 29.8 bulk absorb 2 hours end amps zero. Typical charging amps range from 25 to about 60 so well within the 80 amp limit. My building uses on average 5 Kw-hr/24 hour day which so far has been replaced daily. Since sun hours are now starting to diminish, I would love to halt this peculiar behaviour.

I've visited the Outback forum but it presently has locked me out; can't change password etc.

FWIW the unit will reset itself and go back into tracking and bulk charge modes but will then inexplicably go back into snooze mode sometimes within a few minutes.

Do I have a lemon here?

petertearai

Is it the voltage getting lower? Either less sun or a panel failure? My fm80 snooze when low light  

706jim

No, the voltage is well within the charging range and full sun. I'm going to try a reset to see if that helps. If all else fails there's still the 100% reliable C40 which I kept as a spare.

BB.

There has been historic questions about Outback solar chargers "sleeping" during the day:

https://forum.solar-electric.com/discussion/10407/outback-flexmax-80-always-snoozing
https://forum.solar-electric.com/discussion/18280/mx-60-controller-stuck-in-sleeping-mode
https://forum.solar-electric.com/discussion/3472/fun-with-mppt-whats-causing-this

You can search the forum by typing into Google, duckduckgo, etc. (you can change the site tag to any website):

site:https://forum.solar-electric.com outback controller sleeping

This has been a going back 12 years:

http://www.outbackpower.com/forum/viewtopic.php?f=29&t=3142&p=18784&hilit=current+sense#p18784

I do not know what the "present sleeping issues" may be... Contacting Outback service may be a good start.

-Bill

706jim

Thanks Bill. Have emailed Outback to see if they have any suggestions.

BB.

Jim,

Let us know what cures its ills!

-Bill

wellbuilt

Default to factory settings fix a lot of problems with the outback stuff when it starts acting crazy. 

 I would default  to factory setting then reprogram , I would bet it will start to work properly

706jim

Thanks Wellbuilt will be trying that. Will reset clear my two months of logged data?

Vic

706jim said:

No, the voltage is well within the charging range and full sun. I'm going to try a reset to see if that helps. If all else fails there's still the 100% reliable C40 which I kept as a spare.

But,  just out of curiosity,  when the CC is Snoozing,  what is the input voltage to the CC?
When the CC is Bulking,  what is the Vin,  then ?

Thanks,   Vic

wellbuilt

I’m not sure about the data log ?
  Some things Change back but a lot of my setting stayed the same. 

    The best thing you can do is call customer support and talk to the tech. 

     They are very patient and can walk you thru your setting over the phone . 

  I was having a problem where my fm80 was just switching to absorb early @ 1 hour instead of 3 and some how my setting where getting changed time , day and other things . 

  I up dated every thing in my mate and inverter reset every thing and entered all my info again .
 And it worked . 

   But first reprogram the fm 80 . 

706jim

Vic said:

706jim said:

No, the voltage is well within the charging range and full sun. I'm going to try a reset to see if that helps. If all else fails there's still the 100% reliable C40 which I kept as a spare.

But,  just out of curiosity,  when the CC is Snoozing,  what is the input voltage to the CC?
When the CC is Bulking,  what is the Vin,  then ?

Thanks,   Vic

When snoozing voltage in is about 41 while battery voltage will be somewhere between 24.5 and perhaps 27. When bulking the voltage in will drop down to mid 30's and will rise as the batteries approach full charge. Logging data is not affected by charge controller rest to factory defaults.

Dave Angelini

You are close on the voltage being too low and with different panel orientations on one mppt, it could be fooled. It also could be fine and something is not configured right or wiring is intermittent.  It also could be a lemon....  See what Outback says tomorrow. You on the their forum for this?

706jim

The Outback forum is presently inaccessible. Down for maintenance so you can't access it or register. Hopefully it will be back in action soon. I have a post regarding this problem there. 

Dave Angelini

I was in the forum last 3 days including right now. Are you signed up?

Rethinking, I think you need to rewire, just because you saw mide 30's on the solar does not mean that it dipped and triggered snooze. If it is not hard to do this, I would. Even a decent logging voltmeter might miss a cloud voltage drop. They are fast.  The loss at 2 panel in series when charging is almost negligible offgrid for 24v.

It would drive many of my clients nuts to see a load come on in the day and not be covering it with the solar. If you rewire you will have less drop on the wire run and can add even more panels.

Dave Angelini

Found your post and below is what was said. I am not sure there is much help below for you at this time. Good Luck! Go for a swim👍

pss

Forum Czar

Posts: 578

Joined: Mon Jul 24, 2017 8:40 am

My RE system: 8330 watts in three strings, Flexmax 60 x 3, Radian 8048A, GSLC load center, Mate 3S, Hub 10.3, FN-DC and 900 Amp, 48V Trojan T105-RE battery bank.

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Re: FM80 snoozing

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Unread post by pss » Sun Jul 26, 2020 9:12 am

If temperature is not the problem, then think of this:

Your battery bank has 740 amps at 24 volts. That's 17,760 watts. If discharged by 50%, that's 8,880 watts. You have 1980 watt array, split into 2 directions, so really a 1K watt array at any time. Therefore, YOU CANNOT CHARGE YOUR BATTERIES WITH PV.
Next, you have an inverter that does not communicate with your charge controller. And you are reliant on what little PV you get PLUS either generator or grid or both to properly charge your batteries. It is necessary to put the Flexmax 80 at the "head of the class" when PV is present by making certain that the voltage settings for bulk/absorb are 0.2-4 volts higher on the Flexmax than on the inverter or generator. Set your absorb time to 4 hours.
Since your system can be termed 'unbalanced", meaning too little PV to support the size of the battery bank, you can either remove one of your strings of batteries and charge it with a different source entirely or add PV. For that size battery bank, about 6K watts of PV depending on your location would do the trick with another Flexmax 80, add a Outback hub and a Mate 3S too.
Now for your question, the charge controller may just be experiencing voltages that are too low or amps too low and deferring to the charger on say an inverter if that is present and heat is not an issue. That is why it is important to make sure settings on both chargers are correct. Your inverter has a 25 amp AC charger, that is 3,000 watts, at say 28 volts, that would be 107 amps into your battery bank. That would overwhelm your Flexmax 80 capacity. And your batteries should have their maximum charge current set properly which is about 13% of the C20 hour rating. In your case this is roughly 96 amps of charging current at one time from all sources.

Would like to hear more about your settings then to add further insights.

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706jim

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Posts: 16

Joined: Tue Apr 28, 2020 10:52 am

My RE system: 6x330 watt Canadian solar panels 8x370 ah Trojan L16's Flexmax 80 Trace DR1524 Msw

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Re: FM80 snoozing

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Unread post by 706jim » Tue Jul 28, 2020 12:51 pm

Absorb time is set to two hours. Bulk voltage 29.8 float voltage 27.6. Equalize 31.0 so the inverter won't shut off due to over voltage. As to "you can't charge this battery bank with PV", not so. I use on average 5kw-hr per 24 hour day and the array easily brings the bank to float on a sunny day usually by 2pm at this time of the year. If the battery doesn't reach float by 1pm, both sets of panels will be charging and I would get between 40 and about 57 amps to the batteries. Not 10-13% but greater than 5%. It just seems odd that the controller would go into snooze mode in the middle of a sunny day whereas it otherwise went through a normal wakeup tracking bulk absorbing and float regime for the past two months. When the peculiar snooze event happens at least the controller resets itself and carried on with charging.

While I don't disagree with Trojan's 10-13% charging current recommendation, I should point out that I ran a 660AH battery (12 GC's in series parallel) for 19 years (6 month seasons) with only 400 watts of solar charging them. So you CAN charge a large battery with less current if you don't kill them with excessive DOD. When I started PV in 1994, panels were awfully expensive and batteries relatively cheap. That minimal system usually reached float by the end of a sunny day as well. I increased panels and batteries two years ago to allow an electric fridge to be used.

As for grid tie, I'm on an island in Lake Superior. There will never be grid power out here so PV will be doing all of the charging.The Trace has a 35 amp charger that could be used with generator backup but I'm sure this is 35 amps at nominal 24 volts; about 700 watts.

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pss

Forum Czar

Posts: 578

Joined: Mon Jul 24, 2017 8:40 am

My RE system: 8330 watts in three strings, Flexmax 60 x 3, Radian 8048A, GSLC load center, Mate 3S, Hub 10.3, FN-DC and 900 Amp, 48V Trojan T105-RE battery bank.

Contact: 

Contact pss

Re: FM80 snoozing

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Unread post by pss » Tue Jul 28, 2020 1:04 pm

If you are not really discharging your battery to any degree, you can "charge" it back up. But if your PV size is correct, you cannot discharge that size battery bank to any degree as the math does not add up.

706jim

An FM80 system reset has not changed the behavior of my charge controller. So far it will reset itself from snoozing to bulk charging mode after about 5 minutes, resuming bulk charging mode and the battery bank has reached float every day. Like many other forum users I am concerned with losing valuable charging time as sun hours decrease. In my case it would be a fairly simple option to rewire both sets of panels in series which would give me about 125 volts VOC. Waiting on comments from Outback before I change anything. As to the above comments solar systems all really come down to "you can't take out more than your put in". I have managed to satisfy this truth so far with both of my solar systems. Including my 660 Ah battery charged with 400 watts of panels (since upgraded) before the addition of the fridge. The panel orientation mentioned in my signature is dictated by shading limitations.

Dave Angelini

Make sure that the temp math is good for your cold winters. Typically you would go for a (2 in series) approach for 72v. There is more conversion loss at 125v down to a 24v battery.

The other side of your current problem is as the temps go down in the fall, the system may operate fine the way it is currently wired. A chess game for sure.

What make of guitar? Looks like one of Malcolm Young's old gretches 

706jim

I own six guitars. That one is a fairly old Yamaha acoustic. The fellow I bought it from told me that it had fallen off the back of a truck and skidded down the highway (in its case) with little apparent damage. The one I've played the longest (not in the picture) is a 1959 Les Paul Junior.

Back to the solar wiring, we use this place from May until the end of October. After that the only loads will be the current needed to run the charge controller. The panels are set 30 degrees from vertical so will shed snow for part of that 6 month period.

Dave Angelini

Cool on the 59 les paul. I had an sg and strat in the day. Too old to rock that hard these days, but thank god for youtube. Still a huge fan of Bonn Scott. Saw him in SF in 1977. There is a nice youtube on pawn shop guitars. https://www.youtube.com/watch?v=mhrHCzc1wlQ

See what Outback says. INO you are too close from 30vdc bulk and solar in at 35vdc. Maybe I am wrong but I would always wire a 24v battery with at least 5o vdc solar or more on mppt.