dokio 300 w system and wire gauge to use

[doublegregg]

hello all. i'm feverishly trying to get up to speed on solar.... i got a dokio 300 w system, an epsolar 40a controller... haven't decided on batteries, altho i have a couple 12v wheel chair batteries. i'm wondering what gauge of wire would be good for the dokio to panel wires. --- if i look at the bluesea chart for wire gauges., for 20amps (at 12 volts i'm assuming)  i can use 10 gauge wire for 3% loss at 15' or 10% loss at 50'.  idk if that is round trip or not -- i mean, the panels are sending electrons one way? 

the reason i got the dokio was the positive reviews, i wasn't sure i wanted panels on my roof (putting in holes, plus i want to be stealth, i think), and i thought i'd park in the shade, put the panels in the sun, etc... 

i also am coming to think that since my controller seems to be able to work at 24 v, that it would be better to have 24 v from my panels --- don't know if this is doable even if i tear apart the wires on the dokio... (probably not into doing this....)

tysm

 

[highdesertranger]

"i mean, the panels are sending electrons one way?"

No the electrons are going both ways. it is a round trip from the Panels to the controller. I used 8 gauge but my panels are much higher voltage just below 80v.

highdesertranger

 

[B and C]

Your panels should say on the back their VOC? voltage, probably something like 17 if these are 100 watt 12v panels. If your controller can only handle 24 volts, two in series would overvolt your controller. An MPPT controller can handle the higher voltages that panels in series produce and turn them into amps going into the battery.

Panels to battery cable size? Ten gauge is most common but the longer the run the more the voltage drops, so a bigger cable yet. This is whatever you are comfortable in taking for losses. I have two 100 watt panels in series that I put out in the sun on a 50 foot 10 gauge extension cord. Since it is series, I don't have a great voltage drop.

Your wheelchair batteries would be a good learner set and they will help you figure out your needs. Call the first set of batteries the learner set because most people kill them because they haven't figured out how to take care of them.

Good luck!

 

[doublegregg]

ok.........thanks........ so if it's 10' from my controller to my panels, i would do my calculations for wire gauge using 20' as the distance.

and for the dokio 300w system, which is 12 volts. i guess i'm 'stuck' with that --- seems like trying to up the voltage by putting them in series would involve ripping up the panels.......

a lot to learn.

 

[Weight]

Some charts have you enter one way distance. The chart figures to round trip. The Blue Sea Circuit Wizard has you enter the total round trip. That is cable to positive and cable to negative, two wires.

 

[B and C]

and for the dokio 300w system, which is 12 volts. i guess i'm 'stuck' with that --- seems like trying to up the voltage by putting them in series would involve ripping up the panels.......

a lot to learn.

Wiring solar panels in series is very easy, take the positive cable of one panel and connect it to the negative of the other panel.  You now have a positive and negative cable left over.  Congratulations, you just wired your panels in series.  
You will need to change your PWM controller in for a MPPT controller though as the PWM won't handle the series panels well.

A note of caution on series panels, if one panel gets partially shaded, it will drastically reduce the charging.  Keep them clean and in the sun, they will work well that way.

 

[Tom_M]

I have seen the 300 watt Dokio panels and they are stitched together in heavy canvas so rewiring them would involve cutting them apart.
[img=400x290]https://images-na.ssl-images-amazon.com/images/I/71iQ1HxYroL._AC_SL1500_.jpg[/img]

I have two regular 12 volt panels that I use with a pair of 80 foot (total of 160ft) #10 wires. This isn't ideal but it works okay for me.

 

[B and C]

Ah, so. A much more proprietary system than I've seen. Whatcha see is whatcha get. I wouldn't try to modify that either.