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Hi All 

 

Just started out in solar spent a lot of money as it seems you do in this game

I have currently got the following 

1 X 2.4kwh Dyness Lifepo4 Battery

12 X 370w Solar panels

Growatt SPF 5000TL HVM 5kVA/5kW Hybrid Inverter.

So what do I use it for ? Saving cost on my crypto mining operation and load shedding protection.

I finally installed the panels this weekend I have some issues but busy dealing with them.

 

I do have a few questions - I see my battery discharges completely as soon as Solar fires up. Is that normal ?

I was hoping that solar would compliment my utility load and reduce my electrical running cost during day.

Is there not away to keep it at like 90% and if there is a shortage blend between Eskom and Solar?

I do feel that Cycling the battery is really a waste if there is utility available ?

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1 hour ago, willietes said:

I see my battery discharges completely as soon as Solar fires up. Is that normal ?

No. When there is PV power available, it is used to charge the battery. If you are in battery mode and your loads are higher than the PV charge power, then the battery voltage will decline. Settings 12 and 13 (same as with Axperts) are used to switch to line (bypass) mode when the battery voltage gets low. These only take effect if setting 01 is SBU or Solar First, but presumably you will be using one of those two. Increase setting 12 (the default is very low at 46 V). Try around 49 V to start with (presuming that the Dyness battery is 15S).

When in bypass mode, AC-in will power the loads, and all the PV power goes to charging the battery. If the battery voltage reaches the value in setting 13, the inverter will change back to battery mode.

Ideally, you should have enough PV power that on an average day, the battery won't get depleted much at all, and bypass mode would be rarely used. Of course, in very cloudy or rainy weather, you need it.

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On 2020/03/16 at 2:04 PM, Coulomb said:

No. When there is PV power available, it is used to charge the battery. If you are in battery mode and your loads are higher than the PV charge power, then the battery voltage will decline. Settings 12 and 13 (same as with Axperts) are used to switch to line (bypass) mode when the battery voltage gets low. These only take effect if setting 01 is SBU or Solar First, but presumably you will be using one of those two. Increase setting 12 (the default is very low at 46 V). Try around 49 V to start with (presuming that the Dyness battery is 15S).

When in bypass mode, AC-in will power the loads, and all the PV power goes to charging the battery. If the battery voltage reaches the value in setting 13, the inverter will change back to battery mode.

Ideally, you should have enough PV power that on an average day, the battery won't get depleted much at all, and bypass mode would be rarely used. Of course, in very cloudy or rainy weather, you need it.

Hi Coulomb

 

Thanks for the sterling advice. If I have to push this up to say 51.2 Should it be ok ? I am trying to reduce battery cycling to make sure I don't reduce the life of my lithium. 

I seems to go to bat mode as soon as the PV picks up light. so that is a bit crappy. I wish I had the ability to have like a threshold wattage on the inverter for PV to move it to bat mode.

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4 minutes ago, willietes said:

If I have to push this up to say 51.2 Should it be ok ?

You can only set it to whole volts, so the closest would be 51.0 V.

Or you could change setting 29 (low DC cutoff voltage) to 49.2 V, making the transition effectively 49.2 + 2.0 = 51.2 V. But then you'll get an annoying low battery warning and beep until the battery reaches 49.2 + 4.0 = 53.2 V.

Assuming a 15S LFP battery, 51 V is 3.4 VPC, which is above the 85-90% SOC 3.33 VPC (rested) plateau, so it may switch immediately. 50 V (3.333 VPC) might be much the same. So 49 V (3.27 VPC) might be the highest practical value.

 

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1 minute ago, Coulomb said:

You can only set it to whole volts, so the closest would be 51.0 V.

Or you could change setting 29 (low DC cutoff voltage) to 49.2 V, making the transition effectively 49.2 + 2.0 = 51.2 V. But then you'll get an annoying low battery warning and beep until the battery reaches 49.2 + 4.0 = 53.2 V.

Assuming a 15S LFP battery, 51 V is 3.4 VPC, which is above the 85-90% SOC 3.33 VPC (rested) plateau, so it may switch immediately. 50 V (3.333 VPC) might be much the same. So 49 V (3.27 VPC) might be the highest practical value.

 

Ok Thanks for that. Will leave it then at 49V.

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Hi all @Coulomb

so I have been looking at my system and question the whole design. 
 

as mentioned I have a crypto mining setup that I want to save money during sunny days by having it run off full solar. on loadshedding I shut them rigs down and enjoy lights on. 
 

my rigs place a load of about 2.7kw - 3kw on the 5kw inverter. At peak for about 4hrs a day I get about 3.3 Is that sufficient? Am I breaking any rules? 

as mentioned before I have 

2.4kwh lithium battery

5kw growat spf5000 off-grid inverter

12 X 370w panels in a 2 series 6 parallel configuration.


I also did notice when the inverter flips between solar and utility the led light in my pv room flickers. 
 

does the battery size also matter seeing I am using it to supplement my overheads of electricity? I see it does discharge the battery when clouds move accross so I am concerned about battery life.

any recommendations and advise would be greatly appreciated! 


thanks in advance

Willie

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16 hours ago, willietes said:

my rigs place a load of about 2.7kw - 3kw on the 5kw inverter. At peak for about 4hrs a day I get about 3.3 Is that sufficient?

I assume you mean that you can count on at least 3.3 kW of solar power for the 4 hours centred around noon. That doesn't leave much spare for the rest of the house, so the battery may have to work hard.

16 hours ago, willietes said:

2.4kwh lithium battery

That's too small for a 5 kW inverter working hard. You need at least 2 2.4 kWh modules, preferably more. Even if you watch the power levels pretty closely, you can be surprised by a sudden cloud cover, and I have no idea how fast you can just turn down the power requirement of your rig. I assume that just switching off the power isn't going to be an option.

16 hours ago, willietes said:

I also did notice when the inverter flips between solar and utility the led light in my pv room flickers. 

LED lights do seem to be sensitive to instantaneous RMS voltage, so this is probably normal, if you're talking about switching from line to bypass modes. In normal line mode, it's smoothly blending AC-in, PV, and battery power, right?

16 hours ago, willietes said:

does the battery size also matter seeing I am using it to supplement my overheads of electricity?

Absolutely.

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  • 5 months later...

Before you start mining you should you should gather all the info about cryptocurrencies that you can. I am not sure that it makes a lot of sense to be mining now. I read online that there is a new cryptocurrency that can't even be mined called IOTA. There are some really good articles that you can find on that subject and it is always better to be prepared. A lot of people rush into crypto world and they end up losing money. It might be even better that you start trading with some promising crypto like TRON or Litecoin. 

Edited by AngeloSmith
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