Complete noob. Yep, another DC solar trailer question

[Dude77]

Hello folks, complete noob to this forum and I hope I'm following proper etiquette posting here.

My DC solar trailer that I've owned for about 4 months is now suddenly having the sunny island SMA inverter keep kicking off. Not throwing any kind of code that I can seem to decipher. Actually, not even sure if it is the unit itself or the midnight classic controller that is causing the issue.

I'm attempting to go off grid. Have a fifth wheel, a rather large one, and from the first day of purchasing this DC solar trailer, while the seller was still there I connected it to my fifth wheel to verify it could power my two air conditioners. It did. I bought, seller left, and I've been running the AC while on the property 2 to 3 days per week without issue until very very recently.

Outside temperatures have begun to spike, first issue was on a day worthy ambient temperature was just over 100°.

I heard my AC suddenly kick off and I was nowhere close to being cool. Walked out to the DC solar trailer to find that the master for the sunny island was asking to be started again. Thought nothing of it and restarted it..... 20 minutes later it did it again. I reset again, this time it took about 40 minutes but it tripped again.

Initial thought maybe it's just too hot. The midnight classic controller box seems to be exceptionally warm to the touch but I still hear the fan going. Cabinet fans were also still working.

I attempted over the next several visits to the property to try and look for error codes, The SMA keeps it showing a warning of a low battery, but the midnight classic is showing my voltage still at 44.4 volts on the two forklift batteries that I thought should be giving me 510 amp hours (510x2 batteries down to 50% is 510 right?).

Have called two shops here in the California Bay area and nobody wants to help since I didn't buy it from them. Happy to post pictures of what I see and of the error codes from the SMA. Still haven't figured out how to get to the error codes of the midnight classic.

I will be checking this thread regularly but I'm also truly short on time with a very recent death in the family and trying to handle that. Any suggestions or specific things for me to check out.... Easily spelled out in noob language would be greatly appreciated.

 

[Rednecktek]

The SMA keeps it showing a warning of a low battery, but the midnight classic is showing my voltage still at 44.4 volts on the two forklift batteries tha

OK, just because most SCC's lie a bit, double check with a meter on the batteries Vs what the Midnite is saying Vs what the SMA is saying. Posting what the settings for float/bulk/etc charge settings will help too.

t I thought should be giving me 510 amp hours (510x2 batteries down to 50% is 510 right?).

Yup, you got that right. Is there a date code on the batteries? It sounds like they could just be old and not holding capacity like they used to, even if it's only 1 of the batteries dragging the rest down it will still cause low voltage errors as the rest of the pack tries (and fails) to compensate.

 

[fromport]

Hello folks, complete noob to this forum and I hope I'm following proper etiquette posting here.

My DC solar trailer that I've owned for about 4 months is now suddenly having the sunny island SMA inverter keep kicking off. Not throwing any kind of code that I can seem to decipher. Actually, not even sure if it is the unit itself or the midnight classic controller that is causing the issue.

I'm attempting to go off grid. Have a fifth wheel, a rather large one, and from the first day of purchasing this DC solar trailer, while the seller was still there I connected it to my fifth wheel to verify it could power my two air conditioners. It did. I bought, seller left, and I've been running the AC while on the property 2 to 3 days per week without issue until very very recently.

Outside temperatures have begun to spike, first issue was on a day worthy ambient temperature was just over 100°.

I heard my AC suddenly kick off and I was nowhere close to being cool. Walked out to the DC solar trailer to find that the master for the sunny island was asking to be started again. Thought nothing of it and restarted it..... 20 minutes later it did it again. I reset again, this time it took about 40 minutes but it tripped again.

Initial thought maybe it's just too hot. The midnight classic controller box seems to be exceptionally warm to the touch but I still hear the fan going. Cabinet fans were also still working.

I attempted over the next several visits to the property to try and look for error codes, The SMA keeps it showing a warning of a low battery, but the midnight classic is showing my voltage still at 44.4 volts on the two forklift batteries that I thought should be giving me 510 amp hours (510x2 batteries down to 50% is 510 right?).

Have called two shops here in the California Bay area and nobody wants to help since I didn't buy it from them. Happy to post pictures of what I see and of the error codes from the SMA. Still haven't figured out how to get to the error codes of the midnight classic.

I will be checking this thread regularly but I'm also truly short on time with a very recent death in the family and trying to handle that. Any suggestions or specific things for me to check out.... Easily spelled out in noob language would be greatly appreciated.

I have such a trailer and my batteries are shot, most I can get from them is 10kWh by doing a full discharge. I have inspected about 9 different trailers and imo none of the batteries had any real capacity left. Also the 10 panels on the trailer are not nearly enough to replenish the batteries on the trailer if they are in a good condition. 44.4 volt is 11.1 volt for a 12 volt battery. that is way to low (0% state of charge). Not strange the inverters kicks off. This time of year (i am in southern cali) I get about 6 Wh/W . My trailer has 10 x 235 watt talesun panels = 2350 watt x 6 = 14kWh (minus the overhead/losses) per day to recharge the batteries. 510Ah x 48Volt = 25kWh usable capacity.
With lead acid battery you need to put in about 20% extra so if you would deplete your 25kWh each day you would need about 30kWh of solar provided energy to keep up.
So the PV panels capacity is about 50% of what is needed to fill it up again, and that is during the best solar days of the year.
That trailer setup was designed for a ponzi scheme, not Real Life usage :-(

 

[Hedges]

I use Sunny Island, with Sunny Boy.
As fromport said, battery voltage is quite low and PV array too small.
With default parameters, Sunny Island should shut off at 80% DoD. Check the battery SoC and voltage on SI's display. Read the manual and see if SoC limits are default or have been changed. My system, I have a relay to disconnect all loads at 70% DoD, while SI keeps operating with no loads (except Sunny Boys) down to 80%.

Are the batteries flooded cell? Check electrolyte levels and fill as needed with distilled water (wear goggles and wash up afterwards.)
Switch inverters off and leave charging until fully charged. PV probably can't deliver the charge rate desired; if battery technical document indicates that is the case, consider disconnecting one of two batteries and charging one at a time for higher current. Tell Midnight to do an equalization charge. (Don't know if it will deliver enough, or if a battery charger would be needed.)

Calculate power production from PV, and power consumption from A/C etc. Determine how much more PV you need.
You may be able to add some more PV on the Midnight, especially if an array oriented differently.

I recommend adding AC coupled PV using Sunny Islands; this makes a very powerful and flexible system. You should be able to use either latest model (-41 series) or almost any older model, so long as in the compatibility list. You can sometimes find new old stock units, and pay as little as $0.10/W to $0.20/W or so. With 12kW of Sunny Island, you can have up to 24kW of GT PV. If the batteries don't have excessive self-discharge you may get by with them for a long time, so long as PV capacity exceeds loads.

https://files.sma.de/downloads/SB-OffGrid-TI-US-en-22.pdf

 

[Zwy]

Hello folks, complete noob to this forum and I hope I'm following proper etiquette posting here.

My DC solar trailer that I've owned for about 4 months is now suddenly having the sunny island SMA inverter keep kicking off. Not throwing any kind of code that I can seem to decipher. Actually, not even sure if it is the unit itself or the midnight classic controller that is causing the issue.

I'm attempting to go off grid. Have a fifth wheel, a rather large one, and from the first day of purchasing this DC solar trailer, while the seller was still there I connected it to my fifth wheel to verify it could power my two air conditioners. It did. I bought, seller left, and I've been running the AC while on the property 2 to 3 days per week without issue until very very recently.

Outside temperatures have begun to spike, first issue was on a day worthy ambient temperature was just over 100°.

I heard my AC suddenly kick off and I was nowhere close to being cool. Walked out to the DC solar trailer to find that the master for the sunny island was asking to be started again. Thought nothing of it and restarted it..... 20 minutes later it did it again. I reset again, this time it took about 40 minutes but it tripped again.

Initial thought maybe it's just too hot. The midnight classic controller box seems to be exceptionally warm to the touch but I still hear the fan going. Cabinet fans were also still working.

I attempted over the next several visits to the property to try and look for error codes, The SMA keeps it showing a warning of a low battery, but the midnight classic is showing my voltage still at 44.4 volts on the two forklift batteries that I thought should be giving me 510 amp hours (510x2 batteries down to 50% is 510 right?).

Lead acid takes absorption to get to full charge, that takes time. Even if you have a large PV array, it doesn't do any good if the batteries can only be charged at a slow rate. So out of the gate you are low on battery capacity. It doesn't surprise me you are sitting at 44V, which is very low charge.

Have called two shops here in the California Bay area and nobody wants to help since I didn't buy it from them. Happy to post pictures of what I see and of the error codes from the SMA. Still haven't figured out how to get to the error codes of the midnight classic.

I will be checking this thread regularly but I'm also truly short on time with a very recent death in the family and trying to handle that. Any suggestions or specific things for me to check out.... Easily spelled out in noob language would be greatly appreciated.

Have you serviced the HVAC units lately? Condensers can get blocked airflow over time, this leads to higher head pressures, more amps to run the compressor. This eats into the battery SOC quickly.

 

[Dude77]

Omg, you guys are awesome.

I'll see if I can answer a couple of the questions right now, however I'm away from the property and the earliest I would be there again to actually physically check anything is going to be approximately 5 days from this posting.

 

[Dude77]

Not sure where to even start but here we go

Yes they are lead acid batteries they were the stock ones and going completely off of memory they were the GMA?

For my first posting I guess I double noobed it. Typically when I arrive to the property and open the unit up to get it going the midnight classic controller is reporting the battery is typically between 49.2 to 51.6 volts. Forgive me I can't remember who posted it above but you might have already nailed this issue on the head, I think my batteries just might be discharging too quickly. As said, for the better part of 3 months I've been able to run the unit from the time I get there which is typically sometime between 10:00 a.m. to 11:00 a.m. and run it until probably 4:00 or 5:00 or 6:00 p.m. and the discharge typically hasn't gone below 44 or 45 volts, with notable exception one time it went down to 40 volts but the SMA did not trip off

 

[Dude77]

I hate to have to admit I am the classic could of should of would of.... I downloaded the SMA PDF but simply put it's a little out of my league. I understood car electronics, more specifically stereo electronics for years. But all things solar I've been staring at for the better part of a year and I still feel the equivalent of a third grader trying to talk to 12th graders

 

[Dude77]

Here is the highest battery voltage I've seen.

 

[Dude77]

This was the picture I took before shutting down the unit yesterday after the SMA tripped for probably about its 6th time

 

[Dude77]

Difficult to see but this is the only code that I can seem to bring up or see in the SMA

 

[Dude77]

This is the label on the batteries

 

[Dude77]

What I read previously elsewhere and what I was told by at least two shops was I needed to equalize the batteries and check them, I also would probably do well to get myself a big enough generator to really stuff some power back into these things. Originally the trailer I bought did not have the generator option. But quite literally less than 2 weeks ago I purchased one of the Kabuto low boy 11 KW used from a gentleman who was parting out his DC solar trailer.

Again I hate admitting stuff that I don't know how to do but here I am, I absolutely just simply do not know how to equalize the batteries. I don't even know where to start. I thus far have not connected the generator to The trailer with the batteries and solar panel and controllers simply because of the fact that the generator sits on a trailer just far enough away that I had to order an entirely different cord to span the distance and that only came in the mail approximately 4 or 5 days ago

 

[Hedges]

There's an awful lot in the SMA manual, but start by turning the inverter on and going through the steps to quick-configure a system. Just write down each parameter without changing them. It will be 2phase2, lead-acid of some capacity, nominally 48V.
Then find the charge parameters. There is a max amperage charge (quite large, but won't happen without way more PV), and a smaller amperage charging from AC input.
There will be voltages and times for absorption, float, equalization. I don't know if those were set according to the GNB battery documents or not. With suitable charge settings you should be able to feed AC from grid or generator into the inverter and have it do an equalize cycle.

F716 Malfunction
"F716 2 Measuring range of battery voltage exceeded" on page 205

Battery documents should give equalizing parameters. Sunny Island settings should implement those. May have a periodic cycle, but probably you can force a cycle (with power coming from AC input.)

 

[Dude77]

As for the HVAC units, the trailer is quite literally new in sorts. It was purchased in 2020 as a 2020 unit but has promptly sat, never once used on the dealer lot until 4 months ago when I got it up to the property. Truly just guessing or fathoming I guess the HVAC unit has run maybe a total of 50 times since putting it on the property

 

[Dude77]

There's an awful lot in the SMA manual, but start by turning the inverter on and going through the steps to quick-configure a system. Just write down each parameter without changing them. It will be 2phase2, lead-acid of some capacity, nominally 48V.
Then find the charge parameters. There is a max amperage charge (quite large, but won't happen without way more PV), and a smaller amperage charging from AC input.
There will be voltages and times for absorption, float, equalization. I don't know if those were set according to the GNB battery documents or not. With suitable charge settings you should be able to feed AC from grid or generator into the inverter and have it do an equalize cycle.

F716 Malfunction
"F716 2 Measuring range of battery voltage exceeded" on page 205

Battery documents should give equalizing parameters. Sunny Island settings should implement those. May have a periodic cycle, but probably you can force a cycle (with power coming from AC input.)

Okay not at least gives me some place to start and something to do. Again it's probably going to be four or five days from the date of this posting before I make it back to the property. Would just love to head up there fully armed with the host of things to do or try. Truly truly appreciate your posting and everyone else that is contributed so far

 

[fromport]

Here is the highest battery voltage I've seen.

It still says it is in bulk mode -> max charging. And your 24 amps is not making a dent for those batteries.
I just checked mine: unloaded, islands are off at the moment and I have different (currently partly shaded) panels hooked up it

As you can see the voltage is already way higher and not even in float mode.
When I hosed off my panels last week, one of the batteries started smoking so I disconnected it for now.
Water must have bridged the 48V somehow. :-(

 

[Dude77]

OK, just because most SCC's lie a bit, double check with a meter on the batteries Vs what the Midnite is saying Vs what the SMA is saying. Posting what the settings for float/bulk/etc charge settings will help too.

Unfortunately this is where I'm still playing extreme catch up, lost every tool I had in the 2020 LNU fire. I don't even have a voltmeter. Even a recommendation on which one to get in order to read currents would be helpful. I don't want to just buy some garbage harbor freight one

 

[Dude77]

It still says it is in bulk mode -> max charging. And your 24 amps is not making a dent for those batteries.
I just checked mine: unloaded, islands are off at the moment and I have different (currently partly shaded) panels hooked up it

As you can see the voltage is already way higher and not even in float mode.
When I hosed off my panels last week, one of the batteries started smoking so I disconnected it for now.
Water must have bridged the 48V somehow. :-(

Okay I think I understand, but please clarify if I don't, how do I get it out of bulk mode and what am I switching it to? I certainly gather it's going to be at the midnight classic, but which sub menu do I need to be looking for?


Sorry to hear about your battery, I think that's about where I would pack it in if I were me and start calling an electrician, I'm just quickly approaching the phrase out of my depth very quickly

 

[fromport]

Okay I think I understand, but please clarify if I don't, how do I get it out of bulk mode and what am I switching it to? I certainly gather it's going to be at the midnight classic, but which sub menu do I need to be looking for?


Sorry to hear about your battery, I think that's about where I would pack it in if I were me and start calling an electrician, I'm just quickly approaching the phrase out of my depth very quickly

Once the battery is nearly full it will automatically go to float mode. it is not a setting you have to adjust. your battery is just empty