Hi all , I’m pretty new to having a solar inverter 

so my question is how many panels would it take to charge my setup ? 
 

Some info , I have a 8kw deye hybrid inverter , 16x 550w PV and 5x 5kw Hubble  batteries 

 

right now when checking the status of charging the batteries through the PV it’s showing between 2.5-3kw from 10am 

but I find that it doesn’t have enough time to charge when sunsets at 5ish ( it’s winter now so it’s early) . I thought getting 16PV would be enough , and I get that I’m not going to use 100% of its capability but at this point I’m not even getting close to 50% , roughly 35-38% at its peak When sun is out 

 

anyone can help me understand this better ? It’s there settings to change or do I need more panels ? 

OK... so you have about 8kW of panels and 25kWh of battery. I have about half the panel power and 40% of the battery capacity.

What we don't know is what your loads are like. The system will prioritise servicing the loads and then will use any excess PV for charging batteries. And you have a lot of battery to charge.

You must be able to get a graph something like this (from my system, which has a different inverter)

I found this very useful when I first I first got my system. It allowed me to see when I was using electricity (yellow line), when I was getting PV (blue line) and how the battery was doing (purple line is power to or from the battery, green line is state of charge). By moving some loads around using timers, and by imposing some rules (like you can't run the dishwasher, the microwave, the toaster, and the kettle all at once) I managed to make the system work very well for me. My batteries get fully charged on clear days, and, as you see here, we get all the way through the night on the battery.

So give us this extra piece of information, from a nice sunny day so we can see what your panels are doing and what loads you have to service. Then we can address if you have enough PV or not.
 

Also, tell us about your PV. Assumption is 2 strings of 8 . But what are their orientation.

From an inverter perspective, you are limited in the number of strings (yes, the inverter can take 2 x 2 strings), but with those 550W PV you'll easily exceed the current when connecting 2 strings in parallel. 

Off the cuff, you will need at least 100A (20A per battery) to charge them ad infinitum. And you need to provide that excluding your home loads, as @Bobster.mentioned. Depending on how far you want to drain your SOC daily, (say 50%), you will need approx. (500Ah*50%) = 250Ah / 5 hours (till full) = 50A. That represents +- 50A x 54V = 2700W of excess PV available. So because PV exhibits a Bell type curve, you will  need more than that. You still have to contend with losses, home loads, and this time of year, a low sun, shorter sunshine time etc.

Thanks for your replies  @Bobster. and @Sidewinder … Ok so, I’m not so technical when it comes to inverters but I’m trying to learn and figure it out , so bare with me while I answer your questions to the best of my knowledge 

so this was yesterdays reading , as you can see my batteries only lasted till about 11:30

the only time I use the most load is in the mornings at about 4am when the geyser goes on , but that doesn’t count because by that time my batteries are drained and I’m using from the grid 

 

Also I’m not sure how the PVs are setup if there a way for me to check ? And not sure if this info will help but I have 10 PV on one side of the roof and 6PV on the adjacent side 

 

what could my solution be ? Get more panels ? I recently had this installed so if that’s the case it has to wait abit , but my goal is to go off grid 

 

thanks for reading 

What happens at 18:00 and then again at 21:00 is your geyser running at that time?

58 minutes ago, TheCoal.isWet said:

Thanks for your replies  @Bobster. and @Sidewinder … Ok so, I’m not so technical when it comes to inverters but I’m trying to learn and figure it out , so bare with me while I answer your questions to the best of my knowledge 

so this was yesterdays reading , as you can see my batteries only lasted till about 11:30

the only time I use the most load is in the mornings at about 4am when the geyser goes on , but that doesn’t count because by that time my batteries are drained and I’m using from the grid 

 

Also I’m not sure how the PVs are setup if there a way for me to check ? And not sure if this info will help but I have 10 PV on one side of the roof and 6PV on the adjacent side 

 

what could my solution be ? Get more panels ? I recently had this installed so if that’s the case it has to wait abit , but my goal is to go off grid 

 

thanks for reading 

First, your batteries are running down to it looks like 25%. That's the level your system has set beyond which it will not discharge whilst there is grid. So given that the batteries usually protect themselves by turning off at 10% left, you will never have less than a useable 15% of 25kW IE 3kW in hand if there's no grid and no solar.

Reading from left to right we see your batteries still having quite a lot of juice left when the geysers switch on. Then SOC drops off pretty quickly. Load is 5kW, which is not nothing but also not impossibly big. Then the batteries get to 25 ish % and stop discharging (as we just discussed). The next bit is interesting. You have about 3kW of PV from about 10:00 to 15:00 and your batteries do charge. But they get a clobbering again at 18:00. Then they don't do as well as they did the night before. Your graph starts at midnight and SOC is above 50%. The next night you are down to just over 30 by 23:30. And your consumption is generally higher in the evening than during the day - which might not sound that unusual, but with PV you want to reverse that situation if you can.

I'm puzzled that with 16 x 550W panels you are only getting 3kW, but my technical ability is such that all I can do is be puzzled.

I also notice a sudden jump in SOC at about 16:00, when PV is tailing off and demand is actually starting to increase. What happened there? 

What's happening at night? Say 17:00 to 22:00. Can you move any of that to the day? Look at the graph I posted - I'm doing most of the heavy lifting, so to speak, during the daylit hours. Because I paid a lot of attention to that graph I can look at the shapes and tell you what's going on. But my pool pump turns on at 10:00 (earlier in the summer). Dishwasher was run about 9:45. Heatpump (water heating) kicks on at 12:00 as per the timer. Then you say that very low line in the early morning, and late in the afternoon. We are running at that level from about 18:00, so the battery gets a gentle ride through the night. (we do about 200W around midnight - external lights, wifi, alarm system, fridges, stuff on stand-by - you are doing 5 times that. Why?)

So try to do as much electrical work as you can during the day. But also, your PV array which in theory is twice mine, is not delivering twice the performance. So why is that? Your PV seems a bit low, and your loads never drop below a kW.

Lots of questions here.

Do you have comms between the inverter and the master battery in the pack?

NB. We have full gas for cooking. Heatpump for hotwater (fast and lower consumption). LED lighting throughout. So there's some savings there.

Edited May 16, 20242 yr by Bobster.

@TheCoal.isWet tell us more about your PV like direction and angle and also more or less coordinates. It seems you had a sunshine day yet you are only getting 3kW and with a large battery bank more PV might be generated but the above information needs to be provided. 

As you already indicated the PV is weak and one needs to zoom in into that area of your system. 

 

Edit: Ignore. Was pointed out you've got this issue during sunlight.

Okay, but your system is indicating just 2:15h of peak sunshine hours during the day. Am I reading the weather report correctly, that you had overcast weather all day?

Cloudy weather would completely explain why your panel set is generating 17kWh, insufficient to charge a 25kWh battery bank and then still cover your daily use.

Can you find a different historical day earlier in this month when you had a greater amount of sunlight hours? It would probably have been in the region of 4 hours of effective peak hours if you had sunshine all day. Otherwise, when did you start having this problem? Is it new or has it always been an issue?

Edited May 16, 20242 yr by GreenFields

Can you post these screens from your inverter:

Solar (Solar panel detail page). / Li-BMS screen. / Battery Setting screen. / System Work Mode - Time of use

Any chance your battery charge rate is set at 40A.

@Bobster. so that’s the thing the people at home are going to be using electric mostly before 7:30am and from 5pm because everyone is at work during the day 

 

but to name the things we use , mostly TVs a computer and in winter the geyser at night as not everyday it’s warm in the evenings , it is a solar geyser so the only time the geyser uses power is at 4am and through the day it uses the sun to stay warm 

 

looking at the graphs it seems the house consumes 1-1.5kw/h with no1 home , so the fridges , freezers , internet , CCTV 

the stove is gas and we hardly use the oven 

the pool also haven’t used it since the inverter install because I want to figure out how long the battery will last 

 

my main concern is how to get more power out my PV , I’ll upload a picture here for you to see how the PV layout is and north is to the left I’ve draw on the picture 

@Scorp007 I know you asked direction , so hopefully this helps you as well , but how it’s connected I’m not sure , I just know I have 10 on the one side and 6 on the other side 

@GreenFields it’s it cool if I upload those pictures tomorrow then you can have a look at them 

and yes I am charging at 40a that’s the first thing I checked and asked my installer and he told me I mustn’t make it higher as the council breaker in only 40a so the load will be to much 

 

also the weather report on the app is always wrong , I’m using solar man business , and I’m situated in Cape Town 

the location on the app is also set to Cape Town and the weather is most days if not everyday wrong 

Edited May 16, 20242 yr by TheCoal.isWet

16 minutes ago, TheCoal.isWet said:

and yes I am charging at 40a

are you limiting your battery charge current from solar to 40A?
Those batteries are 1C but even at 0,5C that would be 50A max for one battery, with 5 batteries your charge in theory could be 250A.
Please check if the solar charge has also been limited as that will cause the lower than expected solar charge rate.
Your Inverter should have a separate setting to limit the utility charge current. 

Edited May 16, 20242 yr by zsde

1 hour ago, TheCoal.isWet said:

@GreenFields it’s it cool if I upload those pictures tomorrow then you can have a look at them 

and yes I am charging at 40a that’s the first thing I checked and asked my installer and he told me I mustn’t make it higher as the council breaker in only 40a so the load will be to much 

Need clarity here please. Did you set the global charge amps to 40A on the Battery Settings screen as in the image below?

I could be wrong, but if this is the case, this may well be the reason for this issue, and you may need to set it higher. If you've got 8.8kW of panels, I'd just set this Max A Charge at around 165A.

 

Then for the Grid Charge, if the council breaker is rated 40A at 230V (9.2kW), and around 1kW of baseload then i'd suggest the charge Amps from grid could be lower, say maybe around 120A.

BUT, check with your installer before doing it, and double-check the battery wiring and fuse current ratings if they can handle this before changing anything. OR I could be wrong and need to backtrack. Send the pics anyway. Still think your battery comms could be off, or you may be running in Voltage mode, but just guessing.

 

7 hours ago, TheCoal.isWet said:

looking at the graphs it seems the house consumes 1-1.5kw/h with no1 home , so the fridges , freezers , internet , CCTV 

Fridges and freezers don't use much as long as the seals and thermostats are OK. My 200ish W I draw at night includes 2 fridge/freezer combos and a big freezer. Also external lighting, alarm, electric fence, wifi. Do you run a pool pump? That's 750W in my case - during the day. But your graph shows loads never under a kW. That's 24kWh a day before geyser, cooking etc. 

So I'm struck by that figure. If you can get that down then you save money and life gets easier for your system. 

You run a dishwasher at night? Use the timer to run it during the day when you're getting free power. And check if it has an eco mode. Mine does. 

So that load reduction, and what @GreenFieldsGreenfield is discussing with you.

Edited May 17, 20242 yr by Bobster.
Spelllin

I’m uploading the pictures of the screens @GreenFields and to be honest I don’t understand the whole 40a charge 

because that’s the first thing I wanted to change but my installer said no it’s not allowed , and he said that it should even be lower than 40a and when the inspector comes to register is with the city he might even turn it down for me 😳, so that I’m definitely confused on 

8 hours ago, zsde said:

are you limiting your battery charge current from solar to 40A?
Those batteries are 1C but even at 0,5C that would be 50A max for one battery, with 5 batteries your charge in theory could be 250A.
Please check if the solar charge has also been limited as that will cause the lower than expected solar charge rate.
Your Inverter should have a separate setting to limit the utility charge current. 

I don’t charge with the grid , only with solar , but where do I find the charge settings for charging from grid ? As I only see 1 settings for overall charge 

2 hours ago, Bobster. said:

Fridges and freezers don't use much as long as the seals and thermostats are OK. My 200ish W I draw at night includes 2 fridge/freezer combos and a big freezer. Also external lighting, alarm, electric fence, wifi. Do you run a pool pump? That's 750W in my case - during the day. But your graph shows loads never under a kW. That's 24kWh a day before geyser, cooking etc. 

So I'm struck by that figure. If you can get that down then you save money and life gets easier for your system. 

You run a dishwasher at night? Use the timer to run it during the day when you're getting free power. And check if it has an eco mode. Mine does. 

So that load reduction, and what @GreenFieldsGreenfield is discussing with you.

I definitely need to figure out what’s using so much , but bare in mind I only figured that I’m using this much a few days ago , so now I’m switching things off to see what I can do to reduce 

@TheCoal.isWet,

You need to post this screen during the day with full sunshine, so one can see what the volts & amps are doing at that time.

This pics looks like it was taken during night time.

From what I've seen, your panels are definitely underperforming, so  you need to sort out those panels. 

Note that even though 10 are east facing (nice for early morning production), and 6 are North facing, they could be wired 8 east  + 8 north.

A 10/6 split should show up as PV Volts (10) = 417V & PV Volts (6) = 250V. Approximate.

A 8 /8 split should show up as PV Volts (8) = 330V & PV Volts (8) = 330V. Approximate.

If you see anything different, e.g. +- 82V different to the above voltages per string, then it could indicate one panel was wired incorrectly in the string, thus cancelling out 2 panels (yes, that happened at my installation, and if I didn't have decent management tools, my 1 string would be underperforming till this day.)

Edited May 17, 20242 yr by Sidewinder

24 minutes ago, TheCoal.isWet said:

I definitely need to figure out what’s using so much , but bare in mind I only figured that I’m using this much a few days ago , so now I’m switching things off to see what I can do to reduce 

We all go through that 🙂

54 minutes ago, TheCoal.isWet said:

I’m uploading the pictures of the screens @GreenFields and to be honest I don’t understand the whole 40a charge 

because that’s the first thing I wanted to change but my installer said no it’s not allowed , and he said that it should even be lower than 40a and when the inspector comes to register is with the city he might even turn it down for me 😳, so that I’m definitely confused on 

Okay, so the battery BMS communication seems to be okay.

But as said by @Sidewinder, you should re-send pics of the Solar screen once the sun is out and you're generating power.

Just set your Max A Charge to 150A. If your installer set the Max A Discharge to 150A, then I assume a charge rate of 150A must be okay. Remember, you're not charging from grid right now, only from panels, but you are limiting your battery to only take in 40A DC at the charge voltage of 55.5V. This is not the same as 40A AC at 230V from Eskom.

To get to the Battery setting for Grid Charge, once you're on the first battery screen, press the down arrow on the right-hand side of the screen.

@Sidewinder I took that this morning yes , before sunrise , hopefully later the weather clears up and I’ll get a picture when it’s not raining , if not then tomorrow 

 

so I can get that sorted and figure out how the PV are set up 

 

@GreenFields I’ll set that max charge to 150A this afternoon when I get home from work and let you know how that goes 

 

Thansk for y’alls help , really do appreciate it