Growatt SPF5000ES Offgrid 9kw DIY Solar Project

[Pink7]

3 hours ago, Muhendis said:

I think I mentioned that my panels are well past their prime and three are now flawed so their output is suspect. 

Yet I also still get power back into batteries by lunchtime.

That would probably take a lot longer and indeed used to until I changed the batteries the old ones being knackered.

The new batteries are, as I mentioned, lead carbon and one if their attributes is very good charge acceptance which means they will take everything I can give them even though what I give them could be a lot better.

Cleaning the panels looks good but the improvements in performance are really only noticeable before and after midday when the sun is anything but perpendicular to the panels.

That looks a very good bit of kit. Do you also have an oblong bucket? 

Yes I have one of those large oval black ones used when building so it will be fine for this. I was not sold as a set but i picked the items i wanted. I payed just over 1kthb delivered.

 

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[Pink7]

So at this time in getting 4000 Watt level as max, the he time I installed my max level was 7000 watt. This time of the year my one roof side perform better because of the sun position and im just able to get needed power per day so I might after a years experience with all seasons should consider some more panels. I do plan a cleaning pf panels very soon but lets see how much that will improve. I noticed i produce about same in light cloudy weather as in full sunny weather.

 

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[Pink7]

As mention in last post last weeks i was starting to get lower watt level than what im used to. First i thought it was the moment of the sun..then last day i was sure it was quite sure it was a matter of cleaning. But after cleaning still same. Than this morning we found out them my one side of panels have a broken connector so that side is 50% with only 7 of the 14 active. From photo look like the connector is damages and we see some black on the steel frame on the roof. Any idea how this could have happen?

 

Now i make a plan to take down the one panel who block the access to the panel with issue then replace the connectors and test the panel with watt/amp meter.

 

Pink

[Crossy]

Local wildlife maybe??

 

Or just crappy MC-4 connectors.

 

[Pink7]

1 minute ago, Crossy said:

Local wildlife maybe??

 

Or just crappy MC-4 connectors.

 

Yes I was thinking same. I will pull down the 2 affected panels and replace connectors and test them. Hopefully panels still ok. When close up photo i see black on the steel so look like some electrical shock pulled the connector apart and broke it.

 

Pink

[Crossy]

1 minute ago, Pink7 said:

Yes I was thinking same. I will pull down the 2 affected panels and replace connectors and test them. Hopefully panels still ok. When close up photo i see black on the steel so look like some electrical shock pulled the connector apart and broke it.

 

Possibly a bad connection/connector been fizzing for a while and finally failed.

[Pink7]

5 minutes ago, Crossy said:

 

Possibly a bad connection/connector been fizzing for a while and finally failed.

Now I feel it strange i not discovered it before, maybe if it was in front side roof i have seen it before. The good part of this is that I found the reason why I am on low power and it should be fixable.

 

Pink

[Crossy]

A while back one of our arrays of DIY solar flood-lights stopped being able to last all night.

 

The battery pack simply didn't have the oomph.

 

Charging the pack with an actual charger "fixed" the issue for a week or so.

 

The (simple and cheap) charge controller said all was fine and the pack was charging when the sun was awake.

 

It was only when I actually started investigating that I found that the charge current was in fact, minimal (but not zero).

 

The issue was traced to a bad connection inside the junction box on the back of the 100W solar panel which had evidently been fizzing away for a while.

 

I did a thread IIRC.

[Muhendis]

When you mate (nice wording) those MC4 connectors, be sure to fully push them completely together.

 

I had one fail due to that.

 

The 'O' ring inside was letting moisture in and as a result, the copper wire went a bit green before it parted.

 

It felt like it was well assembled and it conducted electricery just fine, but it needed that extra shove to complete the seal.

[Crossy]

@Muhendis do you think there's any mileage in adding a smear of a silicone-based grease to the O-ring before mating??

 

 

[Crossy]

1 hour ago, Crossy said:

I did a thread IIRC.

 

Yer 'tis

 

 

[Muhendis]

18 minutes ago, Crossy said:

@Muhendis do you think there's any mileage in adding a smear of a silicone-based grease to the O-ring before mating??

 

 

It's cheap enough so why not?

 

It will possibly prolong the life of the 'O' ring although, with the exception of the one mentioned, mine have been good for the last 11 years without silicone grease.

[Pink7]

Yesterday afternoon I pulled down the one panel and replaced one connector on each on the two pannels and mounted it all back and connected the wires. This morning i first tested the voltage on the breaker before open it to power the inverter. Now i see power is same or better than the other side of the roof so the fix look to be successfully as for now.

 

Pink

[Crossy]

Any indication what cause the failure?

 

[Pink7]

6 minutes ago, Crossy said:

Any indication what cause the failure?

 

I guess its what you mention last day: bad connection between the 2 panels. The 2 connectors was melted and no other damages to see.

 

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[Pink7]

Generated 31+kw/h today. Its long time since I was able to get this level in a day !!!

 

 

Pink

[Crossy]

 

[Crossy]

7 hours ago, Pink7 said:

I guess its what you mention last day: bad connection between the 2 panels. The 2 connectors was melted and no other damages to see.

 

Yeah, that was the actual failure, but what triggered it, bad crimp, damp, just not quite plugged?

[Muhendis]

3 minutes ago, Crossy said:

 

Yeah, that was the actual failure, but what triggered it, bad crimp, damp, just not quite plugged?

Pink7 mentioned the two connectors were melted.

My understanding of melted connectors, limited though it is, leads me to think it may have got a bit hot.

Resistive connections do things like that. Sometimes they fuse and sometimes they don't.

In the case of a connector it could be the crimp not firm enough. 

I believe this is a fairly recent instal so I would have a look at the calibration certificate of the crimper  

Here are a couple of pictures of a resistive connection within a solar panel.

First the rear view then the front

[Pink7]

1 hour ago, Crossy said:

 

Yeah, that was the actual failure, but what triggered it, bad crimp, damp, just not quite plugged?

Not easy to say but could be it happened around time we got some cleaning done with hose but I dont know whats the chance for any water to have made the issue. Im quite sure it was not matter of not plugged. Both connectors were original connectors on the solar panels so I would expect they to be well crimped..but I guess fails happens.

 

Pink

 

 

[Muhendis]

5 minutes ago, Pink7 said:

Not easy to say but could be it happened around time we got some cleaning done with hose but I dont know whats the chance for any water to have made the issue. Im quite sure it was not matter of not plugged. Both connectors were original connectors on the solar panels so I would expect they to be well crimped..but I guess fails happens.

 

Pink

 

 

I guess this is panel to panel connections.

Warranty?

[Pink7]

25 minutes ago, Muhendis said:

I guess this is panel to panel connections.

Warranty?

Yes it was panel to panel connections.

 

 

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[Pink7]

I need  a way to fasten my pvc wire storage racks for the wires between inverters. breaking boxes etc. My wall is rock hard so i have give up drilling for the pvc racks. Any suggestions for gluing it? hotglue? superglue? silicone?

 

Pink

 

[terryq]

9 minutes ago, Pink7 said:

I need  a way to fasten my pvc wire storage racks for the wires between inverters. breaking boxes etc. My wall is rock hard so i have give up drilling for the pvc racks. Any suggestions for gluing it? hotglue? superglue? silicone?

 

Pink

 

Suggest 'No More Nails'

 

[Pink7]

Lately my inverters at times do not charge by either stop charging or like today just not start up. I took some screenshot from my JK BMS just before and just after restart inverters. When this happens and i restart inverters ( not BMS) charge start right away. Any one have some ideas what can be reason for this behavior of the inverters?

 

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[Pink7]

Had some inverter restarts today after try default charge voltage.Now im back to lower charge voltage as i just remembered i had this issue before and solved it with lower charge voltage to not trig inverter to think battery full.

 

 

Pink

[lom]

47 minutes ago, Pink7 said:

Had some inverter restarts today after try default charge voltage.Now im back to lower charge voltage as i just remembered i had this issue before and solved it with lower charge voltage to not trig inverter to think battery full.

 

To decide when battery is full is a task for your BMS and not the inverter, the BMS should request the charge voltage it needs and the inverter should comply. Batt voltage setting in the inverter should only be done for batteries which don't have a BMS (Lead-Acid, AGM).

[Pink7]

19 minutes ago, lom said:

To decide when battery is full is a task for your BMS and not the inverter, the BMS should request the charge voltage it needs and the inverter should comply. Batt voltage setting in the inverter should only be done for batteries which don't have a BMS (Lead-Acid, AGM).

Yes.. But inverter seems to stop charge at a certain voltage level when it calculate battery to be 100%. When restart inverter it might adjust to 75% battery level and continue charge.

 

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[Pink7]

41 minutes ago, lom said:

To decide when battery is full is a task for your BMS and not the inverter, the BMS should request the charge voltage it needs and the inverter should comply. Batt voltage setting in the inverter should only be done for batteries which don't have a BMS (Lead-Acid, AGM).

From Manual:

User-Defined 2（suitable when lithium battery without BMS communication）If “User-Defined 2” is selected, battery charge voltage and low DC cut-off voltage can be set up in program 19, 20 and 21. It is recommended to set to the same voltage in program 19 and 20 (full charging voltage point of lithium battery). The inverter will stop charging when the battery voltage reaches this setting

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[lom]

^ Yes, any supported battery that doesn't have BMS communication but I guess you have BMS comms.

 

^^ BMS continuously tells inverter about the SOC so the inverter will know when it is at 100%. If BMS wants to balance batteries then it can request a lower voltage from the inverter.