Voltage and amp loss

[Lakepirate48]

Hi
I just found this forum, nice!
Basic question. Ive an off the grid cabin. (6) 100watt panels, 400 amp hours in batteries. My cables distance from my solar panel is about 100’. 10awg cables. I never seem to get my batteries to float mode. I’ve not great sun access. I’m wondering if I need to shorten my panel cable run, or run larger panel cables? Or, is the amp loss too little to worry about ?
Thanks!

 

[12VoltInstalls]

wondering if I need to shorten my panel cable run, or run larger panel cables? Or, is the amp loss too little to worry about ?

Well I’m assuming you mean voltage drop over distance, and what panel configuration, and what charge controller. And are these lead batteries?

never seem to get my batteries to float mode. I’ve not great sun access

that is probably the first thing to work on.
then panel config.
How are your panels arranged?

 

[mikefitz]

Details of battery voltage, solar controller, panel setup (parallel or series).
Drop is 2 volts per 10amps.

Assuming a parallel setup and 12volt system, max current with 6 100 watt panels is about 30 amps. The resulting volt drop will cause issues.
The ideal solution, series panel connection and a 150 volt input MPPT controller

 

[Lakepirate48]

I was assuming amp drop from panels to charge controller not voltage? Lead batteries, 12 volt system. Parallel . Sorry for lack of details. I’m thinking of placing panels on cabin roof to eliminate the 100’ present run from panels to charge controller

 

[Lakepirate48]

My panels

 

[MisterSandals]

The panels are all connected in parallel?

Parallel

If so, will your SCC support higher voltage array? Higher voltage (and less amps) will greatly reduce wiring loses.

 

[Lakepirate48]

Details of battery voltage, solar controller, panel setup (parallel or series).
Drop is 2 volts per 10amps.

Assuming a parallel setup and 12volt system, max current with 6 100 watt panels is about 30 amps. The resulting volt drop will cause issues.
The ideal solution, series panel connection and a 150 volt input MPPT controller

Thanks! But I’ll need a little for explanation of the 150 volt input mppt controller lol. I’m not sure how to do a series setup. I’m assuming mine is parallel, but I’m new to all this.

 

[Lakepirate48]

Thanks! But I’ll need a little for explanation of the 150 volt input mppt controller lol. I’m not sure how to do a series setup. I’m assuming mine is parallel, but I’m new to all this.

Google is my friend. lol I’m for sure parallel panel setup. Looking at series. I’ve a mppt charge controller so maybe I should go series.

 

[MisterSandals]

To create a series array, connect the + of panel 1 to the negative of panel 2. Connect + of panel 2 to negative of panel 3…

This will sum the Voc numbers listed on your panels. If it’s within 15% of 150V (SCC max input volts), you can arrange 2x 3S strings and put them in parallel for 3S2P.

 

[MisterSandals]

Google is my friend.

You should post links to these, screenshots make unnecessarily work for helping you.

 

[Lakepirate48]

You should post links to these, screenshots make unnecessarily work for helping you.

Ok will do!!!

 

[Lakepirate48]

https://www.amazon.com/gp/aw/d/B07JXYTFF7?psc=1&ref=ppx_pop_mob_b_asin_title

 

[12VoltInstalls]

12 volt system. Parallel

So first things first.

6) 100watt panels

Picture shows 8

Put them 4S2P for ~88VOC and ~10A.
Voltage drop is essentially a static factor of ‘x’ volts per foot. Your panels at 88VOC will have less loss over distance; the voltage drop will be (in practical not literal terms) the same but a smaller percentage overall.

I’m thinking of placing panels on cabin roof to eliminate the 100’ present run from panels to charge controlle

The 100’ is way less important than sun exposure. If 100’ has better sun don’t move the panels for a small “Loss” that isn’t really a loss- it’s just “the cost of doing business” not a monetary or ethical cost.

 

[Lakepirate48]

https://www.amazon.com/gp/aw/d/B07SVRLMBG?psc=1&ref=ppx_pop_mob_b_asin_title

 

[Lakepirate48]

So first things first.

Picture shows 8

Put them 4S2P for ~88VOC and ~10A.
Voltage drop is essentially a static factor of ‘x’ volts per foot. Your panels at 88VOC will have less loss over distance; the voltage drop will be (in practical not literal terms) the same but a smaller percentage overall.

Ops yes 8, forgot I added 2 lol

 

[Lakepirate48]

I’m not sure how to connect in series as if I remember correctly, my panel connector’s only allow parallel. In other words my positive male only fits into positive female .

 

[12VoltInstalls]

you can arrange 2x 3S strings and put them in parallel for 3S2P.

His pic has eight panels so 4S2P is perfect for 150A controller

I’m not sure how to connect in series as if I remember correctly, my panel connector’s only allow parallel.

Instead of using cascading parallel cables you’d only use one pair.
Mr Sandals instructed on series

 

[Lakepirate48]

So first things first.

Picture shows 8

Put them 4S2P for ~88VOC and ~10A.
Voltage drop is essentially a static factor of ‘x’ volts per foot. Your panels at 88VOC will have less loss over distance; the voltage drop will be (in practical not literal terms) the same but a smaller percentage overall.

The 100’ is way less important than sun exposure. If 100’ has better sun don’t move the panels for a small “Loss” that isn’t really a loss- it’s just “the cost of doing business” not a monetary or ethical cost.

Sun exposure is about the same at present location 100’ from cabin, or on cabin roof

 

[12VoltInstalls]

I’m not knocking you or being mean but I wished you had checked in here before you bought the panels! Because four 300W ~46VOC panels 2S2P would have probably been about the same price as your eight 100W commodity panels and fully envelop your SCC’s potential.

Sun exposure is about the same at present location 100’ from cabin, or on cabin roof

Up to you then.
I’m not a rooftop fan- though I might be if I was in Arizona or something.

 

[Lakepirate48]

His pic has eight panels so 4S2P is perfect for 150A controller

Instead of using cascading parallel cables you’d only use one pair.
Mr Sandals instructed on seriesMy charge controller is 80 amp, 8 solar panels. I wrote 6 panels forgetting I added 2. The 4S2P I assume means 4 panels in series and 2 in parallel? Going with my original post of only 6 panels