Mysterious issues ~ please help! (pics included)

TLDR; batteries seem to not be charging to their max - need help figuring out the issue

Hey everyone,

New here and wanted to share my setup. I installed it a few months ago but have only recently started living in the space and I've been noticing some weird issues. At a bit of a loss in determining the source problem and I'm hoping someone with a masterful solar gaze will notice something glaringly obvious.

The main issues I've noticed are:
- The power has consistently been going out at night despite using very little energy
- The charge controller has been switching to float (it did this yesterday and my power went out in the middle of last night) when the battery bank clearly isn't full
- The battery monitor has been giving weird readings (saying it's at 0% when there's still power flowing etc). I calibrated the battery monitor to full when the charge controller switched to float, so I'm guessing those issues are connected.
- The solar panels seem to be bringing in way less than they should despite clear sunny skies and the rig isn't parked in shade.
- Generally, feeling like the batteries aren't getting the juice they need and/or there's a miscommunication somewhere along the charging/storing side (the load side has been totally fine except when the batteries are drained)

Full disclosure, I'm completely new to this and recognize I may have chosen an ambitious setup for my first rodeo. Please don't judge my rats nest of cables - the battery bank is obviously very cramped but it's what I had to work with!
Below I've listed the equipment and have some photos attached. Please let me know if I can take more/ provide more information - really want to learn from you all and figure this out

Primary equipment:
4x 200W 24V Rich Solar Panels (series-parallel)
Victron MPPT 150/45 Charge Controller
4x SOK 12v 100Ah batteries (series-parallel for 24V - 200Ah)
Victron Lynx Distributor as busbar
Renogy Battery Monitor
Victron 24V 3000W 70A inverter-charger
24v --> 12v step down converter
furrion 12v distribution panel and blue seas fuse block (for 24v loads)

-Can you give us an overnight consumption in watt hours or amp hours?

-Also, what is your parasitic draw at night? It should be somewhere less than two or three amp. Mine is .5 amps from the fridge, .5 amps from the entertainment system and one amp from the inverter, and perhaps one amp from other things.

-Pic looks like the negative PV in to SCC could not be hooked correctly, but is most likely just the picture.

-24 panels 2S should provide enough voltage 2S even in cloudy conditions to make power and would not exceed the SCC specs. I see that the volts into the SCC are 80 volts, so what are the exact panel specs? I’m assuming a 2S2P setup.
—To trouble shoot this, I’d disconnect the panels one string at a time to see if charging is better on one certain string. A dead panel could take production way down. I have circuit breakers for turning on and off, so that is an easy thing to do.

-You show 190 watts charging on 800 watts of panels. What is typical in light conditions for you.

I also have a spare SCC I can swap out to troubleshoot.

EDIT: I am in central AZ and this time of year, mid January, my flat panels peak at a little over half the total watts. I’m not sure how far north you’d need to be to say the 1/5th you see is normal.

chrisski said:

-Can you give us an overnight consumption in watt hours or amp hours?

-Also, what is your parasitic draw at night? It should be somewhere less than two or three amp. Mine is .5 amps from the fridge, .5 amps from the entertainment system and one amp from the inverter, and perhaps one amp from other things.

-Pic looks like the negative PV in to SCC could not be hooked correctly, but is most likely just the picture.

-24 panels 2S should provide enough voltage 2S even in cloudy conditions to make power and would not exceed the SCC specs. I see that the volts into the SCC are 80 volts, so what are the exact panel specs? I’m assuming a 2S2P setup.
—To trouble shoot this, I’d disconnect the panels one string at a time to see if charging is better on one certain string. A dead panel could take production way down. I have circuit breakers for turning on and off, so that is an easy thing to do.

-You show 190 watts charging on 800 watts of panels. What is typical in light conditions for you.

I also have a spare SCC I can swap out to troubleshoot.

EDIT: I am in central AZ and this time of year, mid January, my flat panels peak at a little over half the total watts. I’m not sure how far north you’d need to be to say the 1/5th you see is normal.

Click to expand...

I'm not totally sure how to determine parasitic draw, but here's what's typically running at night:
50Wh or 5 amps max for a 12v cooler/fridge (highest when compressor kicks on)
2x maxxfans on low (a couple amps estimated)
Inverter (when it's left on, which is only sometimes) is 20 Wh at "zero load power" according to victron
misc devices plugged into 12V to charge (ipad, phones etc)

The panels are hooked up in 2S2P. Attached is the specs for the panels (all four are the exact same). There's been plenty of sunlight and clear skies so I'm not sure why it's bringing in so little when the array should be capable of 800 watts. The highest I saw it today via the SCC app was about 235W.

To clarify troubleshooting, should I disconnect a series pair at a time? AKA disconnect one of the positive+negative connections on a pair to see which one is operating more efficiently? I have a breaker but it's for the entire array, not each string.

Comments.
The Victron solar data Indicates a low battery voltage every day, with a power yield of 1.5 to 2kw. This infers you are using more power than your solar can meet. Reduce your daily load until the issue is resolved.
What is unusual with the charging is 60% in bulk, 20% in absorbtion and 20% in float. This is very unusal with lithium where its expected to complete the majority of charge in the bulk stage.
Check that there is no significant volt drop between the batteries and the solar charger.

Where you have a series parallel arrangement with lithium batteries its important they are all at the same state of charge, fully charged, before building the pack. Check the the BMS allows charge to your expected charge voltage. Example if you intend to charge at 28.4 volts, then the single battery test volts should charge to 14.2 without BMS protection.
A further issue that can occur, since the batteries are not marched in performance, is the BMS in one of the two series batteries entering protection mode due to cell overvolts. This may be occurring. Try reducing the charge volts to a lower value.

The Renogy battery monitor may be giving misleading results, ignore for the moment.

Horizontal panels will have reduced power at this time of the year, you could split the two strings and compare performance. You were getting around 500 watts from your 800 watts of panels, thats resionable. Any shade at all, even a cable over a cell or shadow from roof light, antenna, air con unit will reduce panel output.

I think I can see a Victron battery protect in one of your pictures, what task is this performing?

It would be helpful if you could provide a circuit diagram and a rough idea of your loads AC and DC.
From your last post you power requirements seem modest, far less than the 1.5 kW solar Input

The last set of data fro the Victron charger indicated the battery going from 22 volts, empty, to 28.5 volts, full, with a 1670 watt yield. Even if all the power went to the battery there is clearly something wrong with the charging process and/or the battery pack.

Can you get access to shore power and evaluate the Multiplus charging?

Mike

jessicadavis said:

To clarify troubleshooting, should I disconnect a series pair at a time?

Click to expand...

Yes.

Sounds like you could have half the input. If that’s true, output will drop to 0 when you unplug the good one and stay the same when you unplug good one.

I want to add if it’s easier and it probably is shade a panel in series instead of disconnecting. If wattage goes down the string is good. If it stays the same it’s bad. Each side should go down just as much.

mikefitz said:

Comments.
The Victron solar data Indicates a low battery voltage every day, with a power yield of 1.5 to 2kw. This infers you are using more power than your solar can meet. Reduce your daily load until the issue is resolved.
What is unusual with the charging is 60% in bulk, 20% in absorbtion and 20% in float. This is very unusal with lithium where its expected to complete the majority of charge in the bulk stage.
Check that there is no significant volt drop between the batteries and the solar charger.

Where you have a series parallel arrangement with lithium batteries its important they are all at the same state of charge, fully charged, before building the pack. Check the the BMS allows charge to your expected charge voltage. Example if you intend to charge at 28.4 volts, then the single battery test volts should charge to 14.2 without BMS protection.
A further issue that can occur, since the batteries are not marched in performance, is the BMS in one of the two series batteries entering protection mode due to cell overvolts. This may be occurring. Try reducing the charge volts to a lower value.

The Renogy battery monitor may be giving misleading results, ignore for the moment.

Horizontal panels will have reduced power at this time of the year, you could split the two strings and compare performance. You were getting around 500 watts from your 800 watts of panels, thats resionable. Any shade at all, even a cable over a cell or shadow from roof light, antenna, air con unit will reduce panel output.

I think I can see a Victron battery protect in one of your pictures, what task is this performing?

It would be helpful if you could provide a circuit diagram and a rough idea of your loads AC and DC.
From your last post you power requirements seem modest, far less than the 1.5 kW solar Input

The last set of data fro the Victron charger indicated the battery going from 22 volts, empty, to 28.5 volts, full, with a 1670 watt yield. Even if all the power went to the battery there is clearly something wrong with the charging process and/or the battery pack.

Can you get access to shore power and evaluate the Multiplus charging?

Mike

Click to expand...

Hey Mike,

The batteries are about a foot from the SCC so there shouldn't be significant voltage drop.

When I built the pack I had received them from SOK and left them untouched for about 6 months before connecting. Assumed they were all at the same SOC since they were from the factory but could the sitting have drained them unequally? The recommended charge voltage for these batteries are 14.4-14.6 and the absorption/float voltages in the setting are below this. Should I lower further? (Settings attached)

The victron battery protect was recommended to me as inexpensive assurance that the battery bank wouldn't be harmed by excessive discharge

I have chicken scratch notebooks where I calculated all potential loads while designing the build and determined the system could handle wayy more than I've been putting on it. I've been going very light on it due to the aforementioned issues (often not running AC at all)

Is there a way to diagnose the battery pack? It seems plausible based on your observations that it's not holding charge efficiently

Unfortunately I don't have access to shore power at the moment and I'm totally reliant on solar. This should change in the next month or so but hopefully I can narrow in and fix the problem before then

Testing the battery pack with a voltmeter across each battery may show a voltage difference. This would be a first step.
Identifying current flow in the series paths may indicate issues.

Perhaps the best approach is to break up the pack and individually evaluate and charge each battery idealy followed by a load test

There have been reports that some SOK batteries have been supplied with cell inbalance and thus BMS protection stopping charging at the recomended voltages of 14.4 to 14.6. It's possible reducing the charge volts to a lower value, 13.8, 14.0, 14.2 volts, the BMS will bring the cells more inbalance . Balance circuits are usually designed to function when the battery is receiving charge current and the voltage is over 3.4 volts per cell.

The above issue may exist with one or more of your batteries. Also after 6 months there will have been some perhaps unequal discharge and as delivered its probable they were at different states of charge.

I suggest you charge each battery individually. You could set the Victron charger for a 12v system,( needs to be done via the app, also via the app set a suitable charge current, SOK recommend 20A, max 50A per battery)
Take extra care with the rewire. It should be possible to rig a 12v distribution system to power your 12v appliances and chargers

Once the batteries are each fully charged, you will be aware of the charge voltage each will tollerate before BMS protection, if for example this is 14.2 volts once the 24 volt pack is configured charge at 28.4.

General comments.
You have some high quality units and some not so good items, the Renogy monitor and the 24 to 12 converter for example.
Please tidy the cable runs, I guess you are mobile, vehicle or boat. Over time shock and vibration will cause issues.
Where exactly In your system is the Battery Protect, is itself breaking a load path or is it used as a control command?
You are using more power than I would expect, evaluating exactly where the power is being used would be useful.
Your compressor fridge/ cool box is most likely 12/24 dual voltage, once the issues you are having are resolved it wouldbe more efficient running this from 24 volts.
A DC clamp meter is worth the investment for system testing and commissioning.

jessicadavis said:

I'm not totally sure how to determine parasitic draw, but here's what's typically running at night:
50Wh or 5 amps max for a 12v cooler/fridge (highest when compressor kicks on)
2x maxxfans on low (a couple amps estimated)
Inverter (when it's left on, which is only sometimes) is 20 Wh at "zero load power" according to victron
misc devices plugged into 12V to charge (ipad, phones etc)

The panels are hooked up in 2S2P. Attached is the specs for the panels (all four are the exact same). There's been plenty of sunlight and clear skies so I'm not sure why it's bringing in so little when the array should be capable of 800 watts. The highest I saw it today via the SCC app was about 235W.

Click to expand...

While it might be clear skies and sunny, if the panels are mounted flat, it will kill production this time of year in North America.

Countless RV'ers installed flat solar panels and headed south to areas like Quartzite, AZ for the winter. The system worked great all summer and when they spent the winter in the RV, they found the system could not keep up with usage. The problem is the low sun horizon in winter. By installing tilting panel mounts or using portable panels pointed at the sun it increased production enough to cover the daily consumption.

jessicadavis said:

To clarify troubleshooting, should I disconnect a series pair at a time? AKA disconnect one of the positive+negative connections on a pair to see which one is operating more efficiently? I have a breaker but it's for the entire array, not each string.

Click to expand...

jessicadavis said:

...

When I built the pack I had received them from SOK and left them untouched for about 6 months before connecting. Assumed they were all at the same SOC since they were from the factory but could the sitting have drained them unequally? ...

Unfortunately I don't have access to shore power at the moment and I'm totally reliant on solar. This should change in the next month or so but hopefully I can narrow in and fix the problem before then

Click to expand...

Would it be possible for you to get a generator or borrow one? You really should disconnect these batteries and put them on a charger individually and do a full charge of each. During this you can see if any of the batteries is not performing correctly. You will need a DVM (digital volt meter) to check resting voltages. If the charging goes well than you can connect all the batteries back together run some loads to draw them down and once again put them on the charger to be fully charged.

Your solar production is low but it is hard to see if that is due to a mounting/location situation or possible a connection issue.

@mikefitz @Mattb4 @Zwy @chrisski

Thank you all so much for your recommendations. I was just in the battery bank compartment looking into some of the things you suggested, and I went to turn the red blueseas switch to "OFF" to perform maintenance but then noticed my maxxfans kept running.....

....Aaaaand I believe I found the culprit. This is quite scary/ embarrassing but I'd love if you guys could take a look at the pictures - basically the fuse holder plastic (for the 300A ANL fuse) was being melted on the side of the blueseas switch and consequently not making a clean connection (very corroded)

Can someone help me figure out what happened here? Was it simply an inadequately tightened connection that created resistance overtime? I'm going to replace the fuse & fuse holder but want to avoid this happening again - yikes!

The cable termination lug should be on top of the fuse, followed by the flat washer, then spring washer, then nut,
It looks like a poor quality fuse holder made from acrylic. Inadequate tightening, perhaps incorrect contact between lug and fuse.
I think you may still have other issues. Isolation should not have allowed the fan to run. Is it running from solar?

If its the main battery fuse I suggest a Bluesea fuse holder with a MRBF fuse.

The issue with this fuse connection could be responsible for the strange charge patten I commented on earlier.
The charger would be seeing a voltage higher than actual battery volts.

Mike

Loose connection is a good guess. Another issue that I found on my setup was that the lug had tension on it and didn't sit flat on the terminal stud resulting in a connection along an edge of the fuse rather than the entire surface. I noticed a little warmth and gave it a good eye ball to see the issue.

mikefitz said:

The cable termination lug should be on top of the fuse, followed by the flat washer, then spring washer, then nut,
It looks like a poor quality fuse holder made from acrylic. Inadequate tightening, perhaps incorrect contact between lug and fuse.
I think you may still have other issues. Isolation should not have allowed the fan to run. Is it running from solar?

If its the main battery fuse I suggest a Bluesea fuse holder with a MRBF fuse.

The issue with this fuse connection could be responsible for the strange charge patten I commented on earlier.
The charger would be seeing a voltage higher than actual battery volts.

Mike

Click to expand...

Ok - so just to clarify it shouldn't be hooked up like this? I thought it was weird to wedge a flat washer between the fuse and cable termination lug but saw that method recommended by other electrical companies.

The fans are hooked up to the ac/dc distribution block which is given power by the batteries... so I would assume that they should turn off as long as the blueseas switch is operational and switched to "off". Is that not the case?

I'm hoping you're right and the charging issues clear up after it's reconnected properly. Will report back!

TacomaJoe said:

Loose connection is a good guess. Another issue that I found on my setup was that the lug had tension on it and didn't sit flat on the terminal stud resulting in a connection along an edge of the fuse rather than the entire surface. I noticed a little warmth and gave it a good eye ball to see the issue.

Click to expand...

Everything is very wonky in my battery compartment so I think it's more than likely it wasn't sitting flat - will make sure of it this time around. Thank you!

First - raise the absorption to 14.4 per battery 28.8 on the mppt. That will help get more power into the batteries.

Here are several important tests
1. Battery to mppt voltage: about noon when good sun and your system is in bulk.

Find the digital voltage of the batteries. Say 26.98v
Then find the voltage at the mppt’s terminals. My guess is it will be much higher than the batteries. (If not this isn’t your problem - but it needs checked).

If this is a issue - your batteries are not getting fully charged - even though the mppt thinks they are.

A couple of solutions:
Figure out how much difference and raise your absorption voltage that much.
Second (an expensive option) replace the shunt with a Victron Smartshunt or BMV712. Then setup the VE.Network- the shunt will send voltage, current and temperature(if you buy the optional temperature sensor) to the mppt via Bluetooth. This will correct the differences and the mppt will be using the battery voltage to make the decisions of when to go into absorbing and float.

2. Batteries at different voltages. When charging in absorption (or late bulk), read the voltage of each of your four batteries. Are they all the same? They should be very close. Do this test several times, late absorption would be ideal. Also, first thing in the morning before any solar - if there are significant differences you need to re-balance the batteries.

Good luck with your system.

I should have looked over all your photos before answering.
You have a Victron inverter and a Victron mppt. You really should complete the Victron system!

You really need the Victron Smartshunt or BMV712. Then a Cerbo (or roll your own with a raspberry pi). A touch is very nice so you can see the data without your phone. (Don’t forget the cables to connect everything).

The data you can get from the Cerbo - makes understanding the electric data much easier! Also, at a glance you will know the status of the system and when the system gets off- it is much easier to troubleshoot.

Are you charging thru the Battery Protect? According to Victron that is not allowed and has been seen to fail catastrophically (e.g. melts). Perhaps that is contributing to charging woes?

I don’t think it’s a good idea to put a steel washer between the fuse and the battery cables I would clean the fuse and cable surface apply a little anti ox then washer lock washer nut and torque it to specs

In the video fitting the washer between the fuse and cable lug is not a good idea in my opinion. The sequence on the stud having least resistance and best contact would be flat washer, fuse, cable lug , flat washer, spring washer, nut.
With very high current this style of holder offers an advantage,