Hi Everyone, my first time to post in the Forum. I've been looking around the Forum for about a week now and see really some really wise comments. 

But lets leave that there. I'm installing a SPF5000ES GROWATT inverter and made myself coming to a grinding halt today when I started thinking on how to connect my 8 x 300W 37V mono PV panels to the SPF5000ES GROWATT inverter.

What diffs does it make if I just connect all the panels in series (296VDC and 300W) and not in two arrays that consist of 4 panels each (2 sets of 2 panels in series and then connected parallel) and then connect the two array of set in parallel to get 74VDC and 1200W  or in Series to get 148VDC and 600W  

I will be running 4 x 200Ah Gel Batteries.

Somebodies help with this I will really appreciate, my mind has come to a blank that I cannot think anymore🤦‍♂️

Edited April 16, 20215 yr by Koppies

If I were you, I'd just series up all the panels, for less than 320V and presumably their OC Voltage will be less than 50V each, ten you're ok in terms of Voltage limits and don't need excessive conductor diameter, since you'd be running less than 10A between the 8 series panels and the inverter...

The power produced will be 8 X the panel rating, app. so if, lets say one panel is able to produce 260W, ten the 8 series panel string will combine to produce 8 * 260W, or 2080W app. it should be slightly more but rarely will you see the panels produce rated power.

Edited April 16, 20215 yr by Kalahari Meerkat

Hi @Koppies I have the same inverter connected to 16 360 watt panels. Connected as 2 parralel strings of 8. The Installer said 2 strings of 9 would be fine but I ran out funds at 16 panels.

 

If you haven't bought the batteries I would suggest skipping the lead acid batteries. The inverter supports dyness lithium batteries. You can get 2 for the same price and usable capacity.

I also ran out bravery to increasing the voltage any higher. Since it's getting colder I'm already seeing 360 volts at midday. In summer it was sitting at 300 volts.

So you wanna tell that the cooler the ambient temp is the more efficient the panels get? And the ampage, constant?

19 hours ago, Kalahari Meerkat said:

If I were you, I'd just series up all the panels, for less than 320V and presumably their OC Voltage will be less than 50V each, ten you're ok in terms of Voltage limits and don't need excessive conductor diameter, since you'd be running less than 10A between the 8 series panels and the inverter...

The power produced will be 8 X the panel rating, app. so if, lets say one panel is able to produce 260W, ten the 8 series panel string will combine to produce 8 * 260W, or 2080W app. it should be slightly more but rarely will you see the panels produce rated power.

Kalahari Meerkat, does the wattage not stay at 300w for the panels is in series and in series the voltage increase to 8 x 37vdc = 296vdc and the wattage stay at 300W?

1 hour ago, Buyeye said:

I also ran out bravery to increasing the voltage any higher. Since it's getting colder I'm already seeing 360 volts at midday. In summer it was sitting at 300 volts.

So you wanna tell that the cooler the ambient temp is the more efficient the panels get? And the ampage, constant?

18 minutes ago, Koppies said:

Kalahari Meerkat, does the wattage not stay at 300w for the panels is in series and in series the voltage increase to 8 x 37vdc = 296vdc and the wattage stay at 300W?

Yes the wattage&voltage increases in series but amperage stays the same.

 

Yes again to panels being more efficient in cooler temperatures. 

@Koppies Wattage = Voltage X Current aka W=V*A, so, putting your panels in series, increases the Voltage and keeps the current the same (no need to increase conductor size, since current remains the same) the wattage per panel remains, but is obviously additive. It is rare to see the panels producing at their rated power, when the panels are cool/cold, they will produce higher power, but, of course, once they are in sunlight, they will warm up and power production will drop a bit from their maximum.

Edited April 17, 20215 yr by Kalahari Meerkat

@Kalahari Meerkat  So if the ampage stays the same when panels is in series will the ampage of 8.1 amp be sufficient to charge the batteries? ( 4 x 200ah Gel) you get this high voltage of 296vdc and wattage of 2400watts and a ampage of only 8.1A. or do I need to increase my solar array?

My Solar System_210417_092712.pdf
 

Hi @Koppies

I have a similar system as to what you are proposing / installing. See attached doc.

growatt 5kW SPF 5000 HVM WPV P

150AH 12V x4 Lead Acid Gel batteries

X12 330W poly crystalline modules 6S 2P arrangement 3960Wp

Actual Off the Grid for 2021 thus far

Jan -  Feb 2021                   7hoo - 19h00 

March - April 15 2021          8h25 - 18h00 

Note - Solar charging batteries 24/7 only

 

What I would recommend

Increase your modules to achieve an installed capacity of 5500Wp, if the budget allows. 

Install a Hubble Lithium AM-2   C rating 1C 51V 5.5kW battery x1 see attached spec

 

hubble_lithium_am-2_a4_pamphlet.pdf hubble_inverter_compatibility_list_v1.1.pdf

31 minutes ago, Alex Feldmann said:

My Solar System_210417_092712.pdf 349.74 kB · 2 downloads
 

Hi @Koppies

I have a similar system as to what you are proposing / installing. See attached doc.

growatt 5kW SPF 5000 HVM WPV P

150AH 12V x4 Lead Acid Gel batteries

X12 330W poly crystalline modules 6S 2P arrangement 3960Wp

Actual Off the Grid for 2021 thus far

Jan -  Feb 2021                   7hoo - 19h00 

March - April 15 2021          8h25 - 18h00 

Note - Solar charging batteries 24/7 only

 

What I would recommend

Increase your modules to achieve an installed capacity of 5500Wp, if the budget allows. 

Install a Hubble Lithium AM-2   C rating 1C 51V 5.5kW battery x1 see attached spec

 

hubble_lithium_am-2_a4_pamphlet.pdf 1.48 MB · 0 downloads hubble_inverter_compatibility_list_v1.1.pdf 89.7 kB · 0 downloads

thanks @Alex Feldmann I'm gonna study this. Thank you.

37 minutes ago, Brani said:

You will be charging your batteries at 48V, so in theory 2400/48 =50A.

 

Thanks @Brani you are correct, it looks like I need to redo my Science Class

My Solar System_210417_092712.pdf
 

Hi @Koppies

I have a similar system as to what you are proposing / installing. See attached doc.

growatt 5kW SPF 5000 HVM WPV P

150AH 12V x4 Lead Acid Gel batteries

X12 330W poly crystalline modules 6S 2P arrangement 3960Wp

Actual Off the Grid for 2021 thus far

Jan -  Feb 2021                   7hoo - 19h00 

March - April 15 2021          8h25 - 18h00 

Note - Solar charging batteries 24/7 only

 

What I would recommend

1. Increase your modules to achieve an installed capacity of 5500Wp, if the budget allows. 

2. Install a Hubble Lithium AM-2   C rating 1C 51V 5.5kW battery x1 see attached spec
3. Depending on the roof area install 8 modules now in series 8S and in future another 8S modules in parallel to the existing modules  Thus 8S2P

On 2021/04/17 at 10:37 AM, Koppies said:

thanks @Alex Feldmann I'm gonna study this. Thank you.

How did you connect it up afterwards 

Hi Morne SBR, I connected the 8 x 300W Mono panels all in series so my total VOC is 344VDC.(but I find I need to add another 2 x panels)

I used 25mm battery cables but I doubled the cable to make total cable  size 50mm. The battery cable does not heat up. Just make sure you strap/cableties your positive and negative battery cables going to your fuse and from fuse to inverter together to lower the inductance, if not it can have an effect on your charging and discharging of your batteries (battery efficiency)

 

19 hours ago, Koppies said:

Hi Morne SBR, I connected the 8 x 300W Mono panels all in series so my total VOC is 344VDC.(but I find I need to add another 2 x panels)

I used 25mm battery cables but I doubled the cable to make total cable  size 50mm. The battery cable does not heat up. Just make sure you strap/cableties your positive and negative battery cables going to your fuse and from fuse to inverter together to lower the inductance, if not it can have an effect on your charging and discharging of your batteries (battery efficiency)

 

Thanks for the Info, much appreciated ! 

@Koppies Thanks for the Info once again .

Can i use the Ja solar 490w  ( from power forum store ) ( 37.99 V) mono x 10 in series Total 379.90.

I just received my inverter today and want to buy everything so long .

 

@Morne SBR, need to use Voc , the 490 is 45.33 volts, so total of 453 volts, depending on how cold it gets in your area, you are cutting it too close to the max, I would suggest 9 panels 

  Sorry, did not realize you have a Growatt

Edited June 19, 20215 yr by Tariq
.

3 minutes ago, Tariq said:

@Morne SBR, need to use Voc , the 490 is 45.33 volts, so total of 453 volts, depending on how cold it gets in your area, you are cutting it too close to the max, I would suggest 9 panels 

Thanks @Tariq how much tolerance must it be if the max pv array ocv is 450vdc and pv array mppt voltage range is 120 -430 

The Information I got about mppt voltage is you want to stay somewhere in the middle as too high only happens once.

@Morne SBR, what is the minimum daytime temperature for your area

 

i stay in Milnerton and its always much cooler here because of the sea. maybe +/- 20 ? 

Edited June 19, 20215 yr by Morne SBR

25 minutes ago, Buyeye said:

The Information I got about mppt voltage is you want to stay somewhere in the middle as too high only happens once.

So 8 panels then 

You could go up to 9 panels