Growatt SPF5000ES Offgrid 9kw DIY Solar Project

[Pink7]

Done some small adjustments on JKBMS settings and reduced Growatt charge voltage to 55v  and now it charge in a better way and very less volt difference between the cells.

 

Pink

Edited October 5, 2023 by Pink7

[MJCM]

Sorry for my ignorance, but is the difference in V in the cells not solved by Balancing them? Or does charging solve that as well?

[lom]

13 minutes ago, Pink7 said:

Done some small adjustments on JKBMS settings and reduced Growatt charge voltage to 55v  and now it charge in a better way and very less volt difference between the cell.

How high is your charge current when charging at such low voltage? How long time to fully charge the battery?

[Pink7]

28 minutes ago, MJCM said:

Sorry for my ignorance, but is the difference in V in the cells not solved by Balancing them? Or does charging solve that as well?

I can only speak from my experience this days. With voltage 56v and before that 57v some of the cells picked up much faster on the higher voltage and then BMS got quite busy to try balance out that most by discharging.

 

Pink

[Pink7]

29 minutes ago, lom said:

How high is your charge current when charging at such low voltage? How long time to fully charge the battery?

I have very few days to refer too but charge current most of the time 20-30A. Charge time have been 4-6 hours. With latest settings there is very little or no balancing needed in the end today.

 

 

Pink

[lom]

3 minutes ago, Pink7 said:

I have very few days to refer too but charge current most of the time 20-30A.

So around 0.1c

 

4 minutes ago, Pink7 said:

Charge time have been 4-6 hours.

ok so you only use around half of battery capacity before charging again.

 

I have 5x5KWh (500Ah)  of stacked batteries which is barely enough to take me through from 17 to 07 at which time I charge with whatever the panels can deliver up to a max of 150A which is equal to 0.3c

The batteries are then under best condition fully charged around noon, sometimes not until 16 or  some dark days not fully charged at all.  They are charged with 57.6V and steps down in charge current when they reach 98% SOC where after they get trickle charged with 5A dropping down to a few hundred milliamps while climbing up to 100% SOC.

The deviation between the cells is typical around 20-25mV at 100% SOC and that is good enough for me.

[Pink7]

3 minutes ago, lom said:

So around 0.1c

 

ok so you only use around half of battery capacity before charging again.

 

I have 5x5KWh (500Ah)  of stacked batteries which is barely enough to take me through from 17 to 07 at which time I charge with whatever the panels can deliver up to a max of 150A which is equal to 0.3c

The batteries are then under best condition fully charged around noon, sometimes not until 16 or  some dark days not fully charged at all.  They are charged with 57.6V and steps down in charge current when they reach 98% SOC where after they get trickle charged with 5A dropping down to a few hundred milliamps while climbing up to 100% SOC.

The deviation between the cells is typical around 20-25mV at 100% SOC and that is good enough for me.

Yes you are correct in morning i use to see 55-65% remaining capacity. Last day i see 5W at 05.55. 08.xx I use to have more solar power than usage so charge start, then finish around lunchtime. I have set charge limit to 50A.

 

Pink

[lom]

This is my curve for today, I have set the time frame between midnight and 04.00 to not go below 35% SOC so you can see that happen around 02.30 followed by 1.5 hour of grid usage. From 0400 - 0800 I allow the SOC to drop to 15% and that takes me to 07.30/08.00 without using any more from the grid.

Today was a good solar day so I fed some into the grid to compensate ???? for the absence of sun tomorrow, we are expecting at least one non-productive day after a thunderstorm arriving tonight.

[Fruit Trader]

2 hours ago, MJCM said:

Sorry for my ignorance, but is the difference in V in the cells not solved by Balancing them?

Yes and its a good idea to start the BMS and new cell pack life with a clean slate. Balancing packs of large cells can take some time though.

[Muhendis]

1 hour ago, Fruit Trader said:

Yes and its a good idea to start the BMS and new cell pack life with a clean slate. Balancing packs of large cells can take some time though.

This is true.

Before putting your battery pack to work you really should charge them first. This ensures all cells are at the same level to start with. After that they can be assembled into their working configuration.

This is all well and good for a DIY pack but what about the preassembled units which are plug-n-play?

Hopefully this was done before they were assembled but I doubt it. The problem is that delivering a fully charged unit is not good so the batteries are supposed to be delivered half charged.

As has been mentioned above. Balancing needs to be done prior to putting the battery to use but first it needs to be in a fully charged state. First charge the pack second balance it. Third give the pack a final charge because balancing could possibly reduce the charge to less than 100%. 

Now the pack is ready for work. However, cell balance needs to be regularly monitored and balanced. Ideally the battery pack should be taken out of service for balancing so that charge and discharge voltages do not affect the balancing act.

Please be aware that balancing is very important.

If one cell in a 48v pack is fully charged but all the rest are still at around 80% or so. There is a danger that the already full cell will become overcharged as the charger tries to fill up the pack as a whole. With a good BMS and charger control I would imagine this situation is protected against in the preassembled packs.

[Pink7]

First month on solar completed. The whole month home was 100% run offgrid and produced 701Kwh. Im very happy with the level of power production even in cloudy days. Last days with much rainy weather I have been able to keep it going with good power management but last nigh not so this morning the ATS flipped at 06 or so. Then 2 hours later when battery voltage over over 50v it flipped back to solar power. So now that part of the system tested also. I use a external ATS from my inverters, I dont feed grid power to my inverters. I was happy to see my PC did not needed to restart when the ATS flipped.

 

Pink

Edited November 1, 2023 by Pink7

[Pink7]

Got my first full month electric bill after going solar: Billed for 1 unit ( +fee) 38 bath.

 

Btw very goos to see aseanow back online.

 

 

 

Pink

[Pink7]

On 11/23/2023 at 2:22 PM, Pink7 said:

Got my first full month electric bill after going solar: Billed for 1 unit ( +fee) 38 bath.

 

Btw very goos to see aseanow back online.

 

 

 

Pink

Just so it will be correct and same as posted other places: Total was just under 31thb

 

Pink

[Pink7]

Cleaning day today of may panels. They started to look dusty so we just try trow some soap water from the ladder the shower of the soap with the garden hose. I guess there is better tools for this like a tool to to swipe the panels?

 

 

Pink

[lom]

^

Solar panel cleaning brush, Google is your friend

[Pink7]

15 hours ago, lom said:

^

Solar panel cleaning brush, Google is your friend

Yes google is a great tool for anything. I still think its interesting to get suggestions and views from the forum members here and also try contribute with some content here. My Solar project would never been a reality to get up an such a successfully way if it was not for this forum and its members. When Im thinking about, it my project is quite big as fist timer solar DIY for someone who not even been near a solar panel before.

 

So let me use this opportunity to THANK to all forum members who contributed with advises. info and help to this project.

 

Pink

[007 RED]

Congratulations on your DIY solar project.  It looks a really good job and hopefully it will pay its way in a relatively short time frame.

 

Regarding cleaning your panels:  Its not really a good idea to use soap to clean them, for a couple of reasons: -

 

Firstly, you never know what chemicals the manufacturer has put into the soap to give it that ‘extra’ cleaning boost.  There is a danger that these chemicals may cause the seal between the glass and the frame to break down over time and allow water to get onto the photovoltaic cells, which will cause the panel to fail.

 

Definitely do not use standard window cleaning solutions to clean your panels as these contain alcohol-based substances which will cause the panels seal to degrade fairly quickly.

 

Secondly, even if you flush the panels off with water after soaping them, the soap will still leave a very fine film on the glass which tends to attract dust, so you will be back in the same situation of having to clean the panels again soon.

 

The best solution for cleaning solar panels is rainwater, as opposed to tap water.  Tap water inevitably contains calcium and when the panels dry off, the calcium sticks to the panel’s glass.  Initially this will have little, or no, effect on your array’s output, however, each time you clean the panels this calcium film gradually builds up and will eventually reduce the amount of sun light that strikes the photovoltaic cells of your panels, hence, reduced output.

 

The small-scale system on my carport roof (4 x 415W panels) tends to get dirty fairly quickly due to the fact that we live in an area where there are a several food producing factories nearby which are far from pollution free.  See photo below of my panels after about a month during the ‘dry season’.

 

The best solution for cleaning the panels is rainwater.  During the ‘rainy season’ my panels get a good regular clean without any input from me, which is great, and there is always a noticeable slight increase in the array's output following a good shower.  I collect rainwater in a 1k Liter tank (very basic filtering to eliminate any large particles) which I use specifically for cleaning the panels.

 

Initially I used a hose and soft brush to clean the panels. This was followed by a squeegee to remove any surplus water, and then a cloth to dry them off.  This was hard work, especially at my age. 

 

 

So, I decided to invest in a commercial solar panel cleaning brush.  It was a bit expensive, and some would consider it ‘over the top’, but it has made cleaning the panels a lot easier.  The brush cleaner comes with its own small pump, which is connected to the rainwater tank.  Once the panels have been washed, I now use a small battery powered garden blower to remove any surplus water.  It now only takes about 10 minutes to set up and clean my 4 panels.

 

I’ve attached below some photos of the brush kit and a short video of me using it.

 

 

FYI…. I’ve attached a PDF of the brush spec.   Solar Panel Cleaning Brush Cleaning Equipment Solar Panel Cleaning Rotating Brush For Customized - Buy Solar Panel Cleaning Rotating Brush For Customized,Solar Panel Cleaning Brush,Solar Panel Cleaning Equipment Product on Alibaba.com.pdf

 

Hope this helps and gives you some ideas.

[Muhendis]

11 hours ago, 007 RED said:

Congratulations on your DIY solar project.  It looks a really good job and hopefully it will pay its way in a relatively short time frame.

 

Regarding cleaning your panels:  Its not really a good idea to use soap to clean them, for a couple of reasons: -

 

Firstly, you never know what chemicals the manufacturer has put into the soap to give it that ‘extra’ cleaning boost.  There is a danger that these chemicals may cause the seal between the glass and the frame to break down over time and allow water to get onto the photovoltaic cells, which will cause the panel to fail.

 

Definitely do not use standard window cleaning solutions to clean your panels as these contain alcohol-based substances which will cause the panels seal to degrade fairly quickly.

 

Secondly, even if you flush the panels off with water after soaping them, the soap will still leave a very fine film on the glass which tends to attract dust, so you will be back in the same situation of having to clean the panels again soon.

 

The best solution for cleaning solar panels is rainwater, as opposed to tap water.  Tap water inevitably contains calcium and when the panels dry off, the calcium sticks to the panel’s glass.  Initially this will have little, or no, effect on your array’s output, however, each time you clean the panels this calcium film gradually builds up and will eventually reduce the amount of sun light that strikes the photovoltaic cells of your panels, hence, reduced output.

 

The small-scale system on my carport roof (4 x 415W panels) tends to get dirty fairly quickly due to the fact that we live in an area where there are a several food producing factories nearby which are far from pollution free.  See photo below of my panels after about a month during the ‘dry season’.

 

The best solution for cleaning the panels is rainwater.  During the ‘rainy season’ my panels get a good regular clean without any input from me, which is great, and there is always a noticeable slight increase in the array's output following a good shower.  I collect rainwater in a 1k Liter tank (very basic filtering to eliminate any large particles) which I use specifically for cleaning the panels.

 

Initially I used a hose and soft brush to clean the panels. This was followed by a squeegee to remove any surplus water, and then a cloth to dry them off.  This was hard work, especially at my age. 

 

 

So, I decided to invest in a commercial solar panel cleaning brush.  It was a bit expensive, and some would consider it ‘over the top’, but it has made cleaning the panels a lot easier.  The brush cleaner comes with its own small pump, which is connected to the rainwater tank.  Once the panels have been washed, I now use a small battery powered garden blower to remove any surplus water.  It now only takes about 10 minutes to set up and clean my 4 panels.

 

I’ve attached below some photos of the brush kit and a short video of me using it.

 

 

FYI…. I’ve attached a PDF of the brush spec.   Solar Panel Cleaning Brush Cleaning Equipment Solar Panel Cleaning Rotating Brush For Customized - Buy Solar Panel Cleaning Rotating Brush For Customized,Solar Panel Cleaning Brush,Solar Panel Cleaning Equipment Product on Alibaba.com.pdf

 

Hope this helps and gives you some ideas.

 

This works so well for me

 

[Pink7]

23 hours ago, 007 RED said:

Congratulations on your DIY solar project.  It looks a really good job and hopefully it will pay its way in a relatively short time frame.

 

Regarding cleaning your panels:  Its not really a good idea to use soap to clean them, for a couple of reasons: -

 

Firstly, you never know what chemicals the manufacturer has put into the soap to give it that ‘extra’ cleaning boost.  There is a danger that these chemicals may cause the seal between the glass and the frame to break down over time and allow water to get onto the photovoltaic cells, which will cause the panel to fail.

 

Definitely do not use standard window cleaning solutions to clean your panels as these contain alcohol-based substances which will cause the panels seal to degrade fairly quickly.

 

Secondly, even if you flush the panels off with water after soaping them, the soap will still leave a very fine film on the glass which tends to attract dust, so you will be back in the same situation of having to clean the panels again soon.

 

The best solution for cleaning solar panels is rainwater, as opposed to tap water.  Tap water inevitably contains calcium and when the panels dry off, the calcium sticks to the panel’s glass.  Initially this will have little, or no, effect on your array’s output, however, each time you clean the panels this calcium film gradually builds up and will eventually reduce the amount of sun light that strikes the photovoltaic cells of your panels, hence, reduced output.

 

The small-scale system on my carport roof (4 x 415W panels) tends to get dirty fairly quickly due to the fact that we live in an area where there are a several food producing factories nearby which are far from pollution free.  See photo below of my panels after about a month during the ‘dry season’.

 

The best solution for cleaning the panels is rainwater.  During the ‘rainy season’ my panels get a good regular clean without any input from me, which is great, and there is always a noticeable slight increase in the array's output following a good shower.  I collect rainwater in a 1k Liter tank (very basic filtering to eliminate any large particles) which I use specifically for cleaning the panels.

 

Initially I used a hose and soft brush to clean the panels. This was followed by a squeegee to remove any surplus water, and then a cloth to dry them off.  This was hard work, especially at my age. 

 

 

So, I decided to invest in a commercial solar panel cleaning brush.  It was a bit expensive, and some would consider it ‘over the top’, but it has made cleaning the panels a lot easier.  The brush cleaner comes with its own small pump, which is connected to the rainwater tank.  Once the panels have been washed, I now use a small battery powered garden blower to remove any surplus water.  It now only takes about 10 minutes to set up and clean my 4 panels.

 

I’ve attached below some photos of the brush kit and a short video of me using it.

 

 

FYI…. I’ve attached a PDF of the brush spec.   Solar Panel Cleaning Brush Cleaning Equipment Solar Panel Cleaning Rotating Brush For Customized - Buy Solar Panel Cleaning Rotating Brush For Customized,Solar Panel Cleaning Brush,Solar Panel Cleaning Equipment Product on Alibaba.com.pdf

 

Hope this helps and gives you some ideas.

Thanks allot.. exactly the kind of feedback i hoped for. Where did you buy your cleaner?

 

Pink

[Pink7]

12 hours ago, Muhendis said:

 

This works so well for me

 

The material of this type cleaner seems to be gentle and very suited for solar cleaning. We cleaning from a ladder so i need  it 4-5meter or so. So a diy extender could be the solution.

 

Pink

[Muhendis]

2 hours ago, Pink7 said:

The material of this type cleaner seems to be gentle and very suited for solar cleaning. We cleaning from a ladder so i need  it 4-5meter or so. So a diy extender could be the solution.

 

Pink

My panels are on a flat (and leaky) carport roof so access is easy from the house balcony without a ladder.  I also have a walkway between the two rows of panels.

I gave them a good clean only this morning which is both good news and bad news.

I noticed some flaws in three of the panels. They were cheap from China ten years ago so they're moving up my todo list for replacement next year.

The good news is, they still get my 36kWh battery charged by lunchtime.

 

Forgot to mention. I use a drop of car wash 'n wax liquid in with the water. 

[Pink7]

26 minutes ago, Muhendis said:

My panels are on a flat (and leaky) carport roof so access is easy from the house balcony without a ladder.  I also have a walkway between the two rows of panels.

I gave them a good clean only this morning which is both good news and bad news.

I noticed some flaws in three of the panels. They were cheap from China ten years ago so they're moving up my todo list for replacement next year.

The good news is, they still get my 36kWh battery charged by lunchtime.

 

Forgot to mention. I use a drop of car wash 'n wax liquid in with the water. 

Yes your panels do look easy to clean. Charged before lunchtime is great. This time i have 80% or so of the capacity i had some months back before sun turned more to the other side here but still doing ok. So now fully charged an hour or two after lunch time on a average day.

 

Pink

 

 

[Muhendis]

9 minutes ago, Pink7 said:

Yes your panels do look easy to clean. Charged before lunchtime is great. This time i have 80% or so of the capacity i had some months back before sun turned more to the other side here but still doing ok. So now fully charged an hour or two after lunch time on a average day.

 

Pink

 

 

Yes the position of the sun in the sky does vary a bit doesn't it.

What chemistry batteries do you have and what is your normal nightly depth of discharge (dod)?

[Pink7]

15 minutes ago, Muhendis said:

Yes the position of the sun in the sky does vary a bit doesn't it.

What chemistry batteries do you have and what is your normal nightly depth of discharge (dod)?

 

I have Lifep04 280a 3.2v cells. From the numbers on JK BMS i see i average have around 60%/150-160A capacity left in morning per battery. I have 2 batteries with 16 cells each.

 

Pink

[Muhendis]

31 minutes ago, Pink7 said:

 

I have Lifep04 280a 3.2v cells. From the numbers on JK BMS i see i average have around 60%/150-160A capacity left in morning per battery. I have 2 batteries with 16 cells each.

 

Pink

Those figures work out to just under 29kWh at 40% dod.

Looks like you have things running at optimum best for a good long life.

I use Lead Carbon 36kWh at 30% dod which in theory will give me over ten years longevity.

 

[Pink7]

12 minutes ago, Muhendis said:

Those figures work out to just under 29kWh at 40% dod.

Looks like you have things running at optimum best for a good long life.

I use Lead Carbon 36kWh at 30% dod which in theory will give me over ten years longevity.

 

Yes that was a important part of my whole plan for batteries, inverters and BMS  etc to run everything on moderate capacity and not push any limits for longest possible life of the setup. My guess is that my mid level brands equipment do not have same ability  to run near limits over same time as more costly brands.

 

Pink

[Muhendis]

34 minutes ago, Pink7 said:

My guess is that my mid level brands equipment do not have same ability  to run near limits over same time as more costly brands.

That may be true, but it is also true that some brands are grossly over engineered and could be a whole lot less costly yet still perform just as well. 

There are plenty of less costly inverters, charge controllers and BMS's which perform just as well as the higher priced items, but I'm sure you know that already. 

There are also plenty of thieves out there who conceal their bad products behind false advertising claims.

 

[Pink7]

13 minutes ago, Muhendis said:

That may be true, but it is also true that some brands are grossly over engineered and could be a whole lot less costly yet still perform just as well. 

There are plenty of less costly inverters, charge controllers and BMS's which perform just as well as the higher priced items, but I'm sure you know that already. 

There are also plenty of thieves out there who conceal their bad products behind false advertising claims.

 

+1 Yes I agree on all you mention.

 

Pink

[Pink7]

After some searching I found an expandable aluminum window cleaning equipment on Lazada that I want to try. Max 4.5m the one i ordered.

 

Pink

 

 

[Muhendis]

On 12/17/2023 at 11:58 AM, Pink7 said:

Charged before lunchtime is great.

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.

14 hours ago, Pink7 said:

expandable aluminum window cleaning equipment

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