Hi everyone! ☀️

 

I have an 8 x 550-watt solar panel system with two strings. Last year, I installed PV cables with 2.5 mm electrical cables. So far, everything has been working fine, but recently, load shedding in Zambia has gotten worse, with almost 24 hours of no power. 😫 I'm relying on solar power and batteries, but some of them are starting to give out in the early mornings. 🆘

 

I need to replace the PV cables to reduce power loss from the panels to my Luxpower inverter. Can anyone help me decide whether to use 4 mm or 6 mm cables? 🤔

 

Thanks in advance! 🙏 #SolarPower #LoadShedding #Zambia

9 hours ago, Aziz11 said:

Hi everyone! ☀️

 

I have an 8 x 550-watt solar panel system with two strings. Last year, I installed PV cables with 2.5 mm electrical cables. So far, everything has been working fine, but recently, load shedding in Zambia has gotten worse, with almost 24 hours of no power. 😫 I'm relying on solar power and batteries, but some of them are starting to give out in the early mornings. 🆘

 

I need to replace the PV cables to reduce power loss from the panels to my Luxpower inverter. Can anyone help me decide whether to use 4 mm or 6 mm cables? 🤔

 

Thanks in advance! 🙏 #SolarPower #LoadShedding #Zambia

If you wired 2 strings meaning 4 panels to each MPPT the loss with 2.5mm² should not be too much and not much to gain by going to thicker cable unless you have very long runs to the inverter. 

11 hours ago, Aziz11 said:

Hi everyone! ☀️

 

I have an 8 x 550-watt solar panel system with two strings. Last year, I installed PV cables with 2.5 mm electrical cables. So far, everything has been working fine, but recently, load shedding in Zambia has gotten worse, with almost 24 hours of no power. 😫 I'm relying on solar power and batteries, but some of them are starting to give out in the early mornings. 🆘

 

I need to replace the PV cables to reduce power loss from the panels to my Luxpower inverter. Can anyone help me decide whether to use 4 mm or 6 mm cables? 🤔

 

Thanks in advance! 🙏 #SolarPower #LoadShedding #Zambia

What is the cable distance between the panels and the inverter roughly?

Assuming a typical 15 meters, this is what the losses will typically be:

Cable size	Cable loss	Loss in watts over 15m
2.5mm	9.25%	407
4mm	6%	264
6mm	3.54%	155.76

Edited September 16, 20241 yr by HendrikBigChief

11 hours ago, Aziz11 said:

but some of them are starting to give out in the early mornings. 🆘

That gives me a hint that it is rather your battery capacity that your solar charging profile. Give us the details of your complete setup. Luxpower model battery capacity in kwh and your solar panel manufacturer. Your situation has deteriorated from standby power to off grid and there will need to be changes to your existing system. Most importantly what is your load profile during a 24 hour period.

2 hours ago, TaliaB said:

That gives me a hint that it is rather your battery capacity that your solar charging profile. Give us the details of your complete setup. Luxpower model battery capacity in kwh and your solar panel manufacturer. Your situation has deteriorated from standby power to off grid and there will need to be changes to your existing system. Most importantly what is your load profile during a 24 hour period.

Thanks again. 😊

 

As you can see, around 12 hours in the afternoon, the PV power is not much, even though I have solar capacity. It's 550 watts x 8. ☀️

 

I've got 4 batteries x 150 Ah in parallel. 🔋🔋🔋🔋

 

Can you check the settings? Are they okay, or do I need to change them to 600 ah?

3 hours ago, HendrikBigChief said:

What is the cable distance between the panels and the inverter roughly?

Assuming a typical 15 meters, this is what the losses will typically be:

Cable size	Cable loss	Loss in watts over 15m
2.5mm	9.25%	407
4mm	6%	264
6mm	3.54%	155.76

Thanks sir appreciate to explain easily. 

3 hours ago, TaliaB said:

That gives me a hint that it is rather your battery capacity that your solar charging profile. Give us the details of your complete setup. Luxpower model battery capacity in kwh and your solar panel manufacturer. Your situation has deteriorated from standby power to off grid and there will need to be changes to your existing system. Most importantly what is your load profile during a 24 hour period.

Ok sir here are some more information. 

Luxpower sna5000. 

4 x 150 ah lead acid battery 

Solar panels mix used one from Japan & Chinese. 

Normally 800 watts to rise 2.2 kw when using hot water cattle 

14 minutes ago, Aziz11 said:

I've got 4 batteries 

 

7 minutes ago, Aziz11 said:

4 x 150 ah lead acid battery 

The lead acid batteries normally are 12v. That means 4 x 12v batteries in series will give you 48v@150ah. Lead acid should only be discharged to 50% soc otherwise they would not last. That means you will have 75ah(3.8kwh) to cover your load during evening hours( no pv). Please just clarify the battery configuration as the screen print of the Luxpower flowchart suggest 150ah( 4 x 12v in series.)

Thanks bro. 

I think you need this setting to to check please.