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diy solar

Alarm - but from where?

WorldwideDave

Solar Enthusiast
Joined
Mar 5, 2024
Messages
1,134
Location
90266
Equipment:
  • 12V LiFePO4 200 Ah, only one.
  • bus bars
  • kill switch
  • inline fuses
  • victron 100/20 solar charge controller
  • victron 500A shunt with temp sensor connected to positive battery post.
  • victron cerbo gx
  • outback FM 80 solar charge controller
  • Giandell 2000W inverter
  • 13 of 28 panels racked; 10 connected; 200W BPSolar
Issue:
Day started with 100% SOC.
Used to have 2s2p connected to the victron 100/20 SCC. Was not producing more than 1.7 kWh daily.
Got outback FM80 connected to bus bar. Connected 2s3p to the outback. Outback FM80 produced 3.3 kWh today; Victron 100/20 did 930 Watt hour with 2s2p.
This morning, as soon as sun was bringing in about 400 W of power to the shunt, I fired up inverter, and started my pool pump and heater.
Battery SOC was high after 3 hour program of pool pump ran, so ran again for another 3 hours. Goal is 8 hours daily. After 6 hours, the pump stopped as scheduled. No issues. Battery was at about 90%, went inside the house for an hour.
Came back out, and decided to go swimming. Started up the pool and heater. SOC was still around 89%. After about 10 minutes, started to hear a beep.
I assumed the beep - it was so faint - was from the new outback FM80 SCC. Turns out it was from the cerbo GX. Looked on my phone, and it said battery overtemp warning. I stopped the heater. I stopped the pump. I stopped the inverter. I touched the conductors (2/0) going to the battery. They weren't hot. The lugs weren't hot. The battery post itself was very warm, but not hot enough to burn me.

I waited 5 minutes, and started up the inverter, the pump, and the heater again. No issues.
I usually cannot run the heater for this long due to low SOC after running pump for 3 hours. But with all this new amperage charging the batteries, I can run for 6-8 hours on paper.
I have never gotten an alarm like that. It made me scared. What do we think is the issue here? Battery rated for 100 A discharge, but prefers 60 A constant or less I read. That being said, it's a 120V pool pump and 120V pool heater, and the inverter itself, so I don't know how many amps I was running, but the system did not like it.

Fast forward a few hours. The pool pump and heater were off. The Giandell inverter started making alarm noises itself (much louder than victron - could hear from outside my property and hurried back). Turns out the voltage was somewhere around 14.5 V, which I think is what the Victron SCC is set to (based on Will and others' recommendation). Looks like cutoff for Giandell is at 16 V - from manual: Over-voltage Shutdown: 16V±0.5VDC so 15.5. Maybe it reached 15.5 and shut down? I don't see an over-voltage alarm. Just shutdown. Also the victron is unaware of the Giandell, so alarm was not from the Victron. Also according to the victron VRM reports, SOC never hit below 50% today at all.

I tried to turn the inverter on and just run the pump to lower the battery SOC, but by the time the pump started, the inverter shut down. I turned off the breakers from the panels to the SCC. That way the SOC would not increase why I diagnosed the issue.
After 5 minutes, started system back up, and it was fine. So I turned back on the breakers from the array to the FM 80 SCC. No problems the rest of the day.

The VRM also shows that Victron SCC was in following states, in order: Off, Absorb, Float, Absorb again, Float, then Absorb, then off.
VRM shows the Victron SCC went up to its max 20 Amps today. PV Voltage hit 56.5 once.
My battery temperature sensor went from 55 degrees F up to 100 degrees F, then back down to 70 degrees, then slowly over 4 hours went up to 122 degrees F (I assume alarm went off then), and then back down to 64 degrees.
I do see the consumed amp hours went as high or low as -1.70 Ah, meaning that it was almost at zero at some point. I think that the reports are 15 minute intervals.
When the incident happened (full shut down from inverter) the battery power was at -697 W. Not sure if that is meaningful, but it was the lowest of the day by about 100 watts.
The battery voltage and current hit its lowest point when this happened today. Battery voltage was 12.6, but current (A) was at -55.30.
I'm wondering if the pool pump, which was running a bit faster RPMs today, is drawing close to the 60 amp current and shutting something down.
 
The FM80 produces an audible alarm as the panel in voltage approaches the charge voltage.

I think you have 60 volts DC into a 12 volt system so this shouldn’t be it.

Another reason an FM 80 could get excess heat is the fan dies. When you place your hand by the fan will it blow? This alone does not indicate a fan died since it has its own fan and I think the algorithm is a combo of outside temp and SCC temp.

Also, look at this thread for funny noises from an FM80 https://forum.outbackpower.com/viewtopic.php?t=13647
 
The FM80 produces an audible alarm as the panel in voltage approaches the charge voltage.

I think you have 60 volts DC into a 12 volt system so this shouldn’t be it.

Another reason an FM 80 could get excess heat is the fan dies. When you place your hand by the fan will it blow? This alone does not indicate a fan died since it has its own fan and I think the algorithm is a combo of outside temp and SCC temp.

Also, look at this thread for funny noises from an FM80 https://forum.outbackpower.com/viewtopic.php?t=13647
I've heard the fan come on for the FM80 only when I first give the device DC power before turning the PV breakers on. I'm certain that one of the noises - the faint one - was from the cerbo gx, and the other loud noise was from the giandel inverter. But I will look at that link, thanks.
 
Describe the temp sensor that the Cerbo was monitoring. Is it a lug type sensor you have mounted on your battery?
Shunt temp sensor on positive lug. Check.

Does the battery have any communication (CAN)? or internal temp sensor?

Please use Victron Connect to pull the following charts for the whole day from the shunt directly: current (A), temperature, and voltage (V).
And post them here.

I expect we will confirm what @740GLE has said. That battery is being tortured!
 
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That’s a crazy amount of PV for a small 200ah 12 battery.
The amount that I have or the amount that I’m actually using? I have 28 panels total, 13 are installed, but right now four panels two series 2 parallel go to the Victron 100/20 solar charge controller, and two series 3 parallel is going to the outback solar charge controller.
 
Describe the temp sensor that the Cerbo was monitoring. Is it a lug type sensor you have mounted on your battery?
Shunt temp sensor on positive lug. Check.

Does the battery have any communication (CAN)? or internal temp sensor?

Please use Victron Connect to pull the following charts for the whole day from the shunt directly: current (A), temperature, and voltage (V).
And post them here.

I expect we will confirm what @740GLE has said. That battery is being tortured!
Can I get to this from the VRM? Otherwise, I will be within Bluetooth range. Later today
 
Describe the temp sensor that the Cerbo was monitoring. Is it a lug type sensor you have mounted on your battery?
Shunt temp sensor on positive lug. Check.

Does the battery have any communication (CAN)? or internal temp sensor?

Please use Victron Connect to pull the following charts for the whole day from the shunt directly: current (A), temperature, and voltage (V).
And post them here.

I expect we will confirm what @740GLE has said. That battery is being tortured!
IMG_2907.jpeg
IMG_2908.jpeg
 
I’m not 100% certain how the solar charge controllers work, but I have a theory… Is it possible that the absorption of one solar charge controller is set too high or too low? I’m having trouble figuring out what would’ve raised the battery voltage to 14.5 or above. I feel like all of this happened because there wasn’t enough load to discharge the battery, or that one of the solar charge controllers saw that the battery wasn’t full so it kept pushing Current towards it or something like that. I just don’t know. I have not have an over Current situation before. I lowered the Victron absorption rate from 14.2 to 14.0. That was recommended by a forum member. I reset the FM 80 solar charge controller to the defaults for 12 V. It is doing 3.2 kW per day on average from two series 3 parallel, which is 1200 watts max. The Victron SCC is in the shade completely until about noon, and it does an additional .8 kWh max the three hours it is in the sun. That is 2s2p for 800 watts max and doesn’t come close to 20 amps it’s rated for at 12v. I also ran the load instead of 3 hours mid day ran for 4 hours at an earlier time of day. No issues yesterday. Today I added a half hour to pool schedule and starting 30 minuses earlier. I am wondering if the fact the pool pump reset is playing a factor. Maybe the speed ran lower yesterday and will run the same slower speed today vs the day I had the overcurrent alarm. How would I compare this in vrm?
 
Awesome, thanks.
You are never exceeding 0.25C (50A) either charging or discharging, which is good.

Do you have DVCC limiting the charge current setup in the Cerbo?
It will only know about the Victron SCC, it has no way to know about the FM80 except it will see the current it pushes through the shunt.
So it should backoff the victron scc to compensate.

Abosorption and Float voltage need to be coordinated on the two sccs so you do no overvolt.

3.65v * 4 = 14.6V Under no circumstance should the voltage go above that.
Doesn’t look like it did, which is good.
Personally, I would keep it under 14V (3.5V per cell)
 
It looks like the current yesterday was slightly less maybe 5 A less than the day before. The temperature is about 10° cooler than two days ago. As well.
 
I’m not 100% certain how the solar charge controllers work, but I have a theory… Is it possible that the absorption of one solar charge controller is set too high or too low? I’m having trouble figuring out what would’ve raised the battery voltage to 14.5 or above. I feel like all of this happened because there wasn’t enough load to discharge the battery, or that one of the solar charge controllers saw that the battery wasn’t full so it kept pushing Current towards it or something like that. I just don’t know. I have not have an over Current situation before. I lowered the Victron absorption rate from 14.2 to 14.0. That was recommended by a forum member. I reset the FM 80 solar charge controller to the defaults for 12 V. It is doing 3.2 kW per day on average from two series 3 parallel, which is 1200 watts max. The Victron SCC is in the shade completely until about noon, and it does an additional .8 kWh max the three hours it is in the sun. That is 2s2p for 800 watts max and doesn’t come close to 20 amps it’s rated for at 12v. I also ran the load instead of 3 hours mid day ran for 4 hours at an earlier time of day. No issues yesterday. Today I added a half hour to pool schedule and starting 30 minuses earlier. I am wondering if the fact the pool pump reset is playing a factor. Maybe the speed ran lower yesterday and will run the same slower speed today vs the day I had the overcurrent alarm. How would I compare this in vrm?
Yes, please check all voltage setpoints on the FM80 and the Victron 100/20.
DVCC can partially help.
I’m definitely not the expert in this area, see if someone else will chime in.
 
Someone said I could add another Victron shunt and connect the outback solar charge controller negative cable to that and would at least see what it is doing separately in VRM.

I have no idea what DVCC is, but I certainly have seen it in the settings.

If you tell me what the absorption and float voltage is, should be set at, I will do so. I really don’t understand the differences between those two charge modes and bulk.
 
Yes you could add another shunt to see what is going on with the FM80. The new 300A ones are cheaper.
Those DVCC setting look good to me.

Remember that the cerbo can only control the victron SCC, not the FM80, so if it sees lots of current coming in from the FM80, it will shutdown the 100/20, but that’s all it can do.

@sunshine_eggo , kindly give us some blue wisdom, thanks.
 
I know that the FM 80 does not match these settings. Maybe I got some contradictory advice. Was told to lower the Victron SCC to 14.0 instead of 14.2. That way it stopped before or after the FM 80 I think was the recommendation but I cannot remember which.
 
The goal is 48v and a Victron 250/100 SCC but those cost $600 just for Victron SCC. A few more paychecks. Until then FM 80.
 
I see Equalization is enabled! Not good! That is for Lead Acid.
Actually no it wasn’t, sorry /i misread it. /i set my duration to 0m just to be sure.
I saw the 2h and flipped out, sorry.

In the scc settings, what is your battery preset, turn on expert mode, and look at the absortption and float.
I use User Defined Preset.
 
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I’m trying to figure out when the over temp happens what else is going on. Is it high soc? Is it peak load? Is it peak solar generation?
 

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