Outback FM80 stops charging but other controllers continue

Caribsolar

I'm new to solar and just had my system installed in mid-July.  I had one company do the main installation but I wasn't happy with their service or warranties and got another company to install additional panels and system components.


The first company installed: 

• 24-300w VMN polycrystalline panels (3 in series and then 2 series in parallel I think) panels install in the south
• Midnite combiner with 30A breakers (I think)
• Midnite DC Lightning arrestor on combiner box
• 2 Fungpusun FM80 charge controllers (Outback FM80 copies)
• Midnite Mini disconnect box with breakers
• HP 10,000w inverter (factory manufactures for Aims)
• 24-6V 225AH AGM batteries - 3 strings of 8 batteries per string (Deep cycle 7.3v - 7.5v)
• Ground rod (I also have ground rods at the meter as well as connected to the main panel box for the house)
• Manual change over switch between utility and solar power

I soon realized that the batteries were being discharged too low (46v) and between the daily load and what the panels produced there wasn't enough energy to fully charge the batteries.  The HP inverter by default would switch to utility power at 47v and the first company said the settings couldn't be changed.  I decided to buy more panels and am toying with buying more batteries (but am worried about there being 4 parallel strings - one UK website suggested using busbars to connect the parallels), however, because I was dissatisfied with the first company's service I decided to go to another company. 

In between these times I had an electrician install another panel box into which I had circuits that I wanted to run on utility power put.  I also had a manual changeover switch installed to switch between solar power and utility power for a 20,000 BTU solar hybrid mini split air conditioner.  This uses about 10 kwh per day and runs mostly in the day (during the summer) so it was also preventing the batteries from being charged completely.  I put in the switch so that I could change the power source between solar and utility power once I got additional panels and batteries. 

The second company installed at the end of September:

• 12-305w Intenergy polycrystalline panels
• Midnite combiner box with breakers
• Midnite DC Lightning arrestor on combiner box
• 1 Outback FM 80 charge controller
• 1 Outback hub 4
• 1 Outback Mate 3
• Midnite AC lightning arrestor
  
• Midnite breaker box for disconnecting the batteries
• An auxiliary connection to one of the Fungpusan controllers to an automatic changeover switch to switch from batteries to utility power when the batteries are at about 40% depth of discharge.

I installed an Outback RTS on the battery bank.

So far for October we have been having cloudy days with rain in the afternoons.  My issue with the Outback and its copies is that despite setting the values for Absorbance (58.9V) and Float (54.6v), one of them will always show its state as "Absorbing" when the voltage is not at the set values and have absolutely no current flow to the batteries - no charging while the other two will still be in bulk charging mode.  Looking at the Mate 3 graph I can see a distinct break until the battery voltage drops low enough to prompt the rebulk cycle.  Sometimes one of the charge controllers, usually the Outback will show "Charged" when the batteries are not at the Absorbance voltage, but above the value for float.

I tried setting the Mate 3 for all three to go to float when one is in float but it hasn't worked.  I've calibrated the battery voltage readings to be the same (on the Outback and one copy) and to -0.1v on the other copy.  Can't get it any closer since it's at the maximum allowable to be subtracted.  Ideally I would like all three to continue charging until the batteries have gone through the absorb cycle and into float which should occur in the morning hours to mid-day if all three continued charging.  Today for example, the Outback produced significantly less energy than the copies - 6.9 kwh compared to over 10 kwh for each of the copies!  At 10 am, the Outback was producing more energy than the copies then it started slowing down at 11 am.

I experimented for 2 days with setting the absorbance voltage on the Outback and on one of the copies to 60v and it allowed them both to continue charging, however, I was concerned about over charging the AGM batteries and changed it back to 58.9v (my multimeter shows that the charge controller voltage is out by 0.4 - 0.5v).  Battery temperatures reach a max of 32C - I have a fan directed at the batteries to help keep them cool - I live in the tropics where normal air temperature is at least 30C every day.  I have the temperature set to wide with the lowest value set as 57.4v.

Is there anyway that I can get the charge controllers to keep charging (during the morning hours) so that I can get all three to go through a complete absorbance and hopefully float?  

Raj174

Hello Caribsolar,
As you probably know, there is a global charge control function in the mate 3. However, it requires a Flexnet DC battery monitor for this setting to work , also the charge controllers need to be in GT Mode. You did mention calibration, and I'm sure you did this, but just to be sure, try to calibrate all of the charge controllers as close as possible to the real battery voltage.

Rick  

Caribsolar

Hi Rick,

Thanks for your response.  I did try to calibrate as close as possible to the real battery voltage.  Don't have a Flexnet DC battery monitor though and my system is sort of a hybrid, runs off solar until my battery voltage gets to 48.8v then switches to utility power until they recharge to 52v so I'm not grid-tied per se.    Would the Flexnet DC work in my situation since I'm not really GT or can it be set to GT even though I'm not?

Caribsolar

Dave Angelini

The controllers need to be on the same network. Why do you need the Flexnet Rick? It has been some time so I might be mistaken and maybe because there is not an Outback inverter.

Hmm I still think if they are networked the FM's should all talk voltage set-points.....

mcgivor

Perhaps the clone controllers are not genetically identical to the real FM 80, they my not even speak the same language, so communication may not be possible. Even two identical controllers may have slight differences in transition from one state to another, cable resistance differences between the controller and battery could offset voltage each CC sees as battery voltage. Just some thoughts.

Raj174

Caribsolar said:

Hi Rick,

Thanks for your response.  I did try to calibrate as close as possible to the real battery voltage.  Don't have a Flexnet DC battery monitor though and my system is sort of a hybrid, runs off solar until my battery voltage gets to 48.8v then switches to utility power until they recharge to 52v so I'm not grid-tied per se.    Would the Flexnet DC work in my situation since I'm not really GT or can it be set to GT even though I'm not?

Caribsolar

Sorry, the FNDC is required for global charge control, with the GT settings, but I don't think that is what you need. Probably just float coordination. This is from the mate 3 manual:  

Page 127

Charge Controller Float Coordination

The advanced charger float control menu enables the coordination of more than one OutBack FLEXmax charge controller. (This function also works on MX60 charge controllers with firmware revision 5.11). This enables the devices to enter the float stage, or perform other activities, simultaneously rather than individually. Float Coordination means that when one charge controller finishes a bulk charge and moves into float charge, the MATE3 directs any other charge controllers into a float charge as well. 

MATE3 Settings

Set Points:
Enabled–N=No,Y=Yes

Figure 158 MATE3 Charge Controller Float Coordination Screen 

Rick

Raj174

Dave Angelini said:

The controllers need to be on the same network. Why do you need the Flexnet Rick? It has been some time so I might be mistaken and maybe because there is not an Outback inverter.

Hmm I still think if they are networked the FM's should all talk voltage set-points.....

Good call Dave, made me dig deeper.

Rick

mcgivor

mcgivor said:

Perhaps the clone controllers are not genetically identical to the real FM 80, they my not even speak the same language, so communication may not be possible. Even two identical controllers may have slight differences in transition from one state to another, cable resistance differences between the controller and battery could offset voltage each CC sees as battery voltage. Just some thoughts.

A coment on my own coment. It would appear Fungpusun did a pretty good copy, they do speak the same language, someone took the time to dismantle compare and test. http://www.quan-diy.com/misc/scc/fangpusun.htm 

Caribsolar

I haven't been back in a while but decided to "play" around with the system today.  I set the Mate 3 to "rebulk" at 56V, yet the battery voltage will drop below this and the charge controllers will not change their state.  I have to manually use the Mate 3 to start bulk.  I've set it for float coordination today and the readings on the Optics RE says - all three are in Float but only one (the real Outback) is outputting energy, the other two are at 0.  Typically though, the real Outback produces the least amount of energy, even though it has the 12 - 305w panels.  One of the Fangpusuns is the workhorse and will typically produce around 9 - 10 kwh per day while the other produces anywhere from 8 - 9 kwh, and the real Outback 5 -  6 kwh which seems a waste.  The workhorse rarely goes into float which is why I've decided to try the float coordination again.  For example, despite using float coordination, two of the units are back in bulk, and one is in float and the battery voltage is 52.7v (below the rebulk of 56v).

Everything is on the same network and I tried to get the charge controllers reading nearly the same for the batteries, one is out by about 0.1v.  

BB.

Does each controller have its own controller to battery bus wiring? (Not controller A to controller B to battery)

Bill

Estragon

You may want to see if there's a time to rebulk setting (ie have to be < X volts for Y time to trigger rebulk). The time variable is meant to prevent a rebulk cycle being caused by a relatively brief, heavy load, such as a pump.

westbranch

Do you use  separate sources for the Kwh's produced  and verified them against another independent meter?
Especially since they are clones..... quality of components, etc...

Was there any lightning in the area between the first phase and  the second,,,  install of ONLY 1 SPD?

just a few edge of the paper thoughts......