MC4 to battery post cable?

By locating the controller near the batteries, you can minimize loss and have longer cables from the panels to the controller. Putting the controller on the back of the panels provides for the most portability, but has its draw backs.
Since I have added roof panels and a 30amp ViewStar, I want to bypass the 10amp ViewStar with longer cables to a Y junction in the battery compartment.

5A cuz you have 2x50 watt that on the back suggest Imp of 2.78 each. 2x2.78 = 5.56A

30' may be stretching it, but with a programmable controller, you can up the bulk voltage and/or extend absorption time to compensate or fully charge when you have utility power.

some folks seem happy with flat orientation limitations, other have converters that only do 14.4v with no temp comp or 13.6v!

With a fixed install, the controller is close to the batt to limit voltage drop, portable is a compromise that is likely better than most converters, 100 watts is not much for 2x6v but you might not be a power hog!

red31 wrote:
from
http://www.genuinedealz.com/voltage-drop-calculator

24' (20+4) 12v, 10g, 5A, voltage drop .246v

that means if you reach a 14.6v set point, only 14.354v reaches the batt.
of course as the batt reaches full and say the current is 2A, voltage drop would decline to .1v or 14.5v at battery. That is the nature of the controller being on the back of the panel and AWAY from the battery, but being portable you can re position and tilt for best harvest if ya like.

Thanks again. In your calculations you have 5A and not 10A (as per controller??) I am asking because I am not knowledgeable on the subject.
Looks like from what I read (from Renogy) up to a 3% loss is acceptable (obviously less is desirable), is that correct?
So would this be about the max I could extend the cable length:
30' (26+4) 12v, 10g, 5A, voltage drop .359v 2.99%

thanks Paul

from
http://www.genuinedealz.com/voltage-drop-calculator

24' (20+4) 12v, 10g, 5A, voltage drop .246v

that means if you reach a 14.6v set point, only 14.354v reaches the batt.
of course as the batt reaches full and say the current is 2A, voltage drop would decline to .1v or 14.5v at battery. That is the nature of the controller being on the back of the panel and AWAY from the battery, but being portable you can re position and tilt for best harvest if ya like.

red31 wrote:

deppeler wrote:

red31 wrote:
One could also use the design your own to build the tray cable.

That may cost less. What terminal rings would I choose, I have 2 6V Interstate Deep Cycle batteries?

1/4 and 3/8 gold plated ring terminals are the only options with 10g, go with 3/8.

I'd go with longer wire. If ya have the view star 1024BN you could use the 'other' battery type and up the bulk voltage, I doubt 100 watts is gonna get you fully charged daily so it is a mute point.

For maintenance it doesn't matter much with low current.

Thanks for the info. So do you think I could go 15' (instead of the original 10') plus the 4' tray cable and still be okay or could I go longer?

deppeler wrote:

red31 wrote:
One could also use the design your own to build the tray cable.

That may cost less. What terminal rings would I choose, I have 2 6V Interstate Deep Cycle batteries?

1/4 and 3/8 gold plated ring terminals are the only options with 10g, go with 3/8.

I'd go with longer wire. If ya have the view star 1024BN you could use the 'other' battery type and up the bulk voltage, I doubt 100 watts is gonna get you fully charged daily so it is a mute point.

For maintenance it doesn't matter much with low current.

deppeler wrote:

red31 wrote:
Try this, use the previous linked tray cable with grey sb50
https://www.batterystuff.com/battery-cables-connectors-plugs/custom-made-cable-sets/10ga4ringSB.html

go to design your own cable http://www.powerwerx.com/adapter-cables/design-build-your-own-custom-cable.asp
pick left 50A sb50
pick grey
pick 10g red/black bonded, 10' or so
pick bare ends ($30) and wire the bare end into the charge control batt +/-

I believe your existing wire is 12g and would not crimp well with a SB50 10g barrel.

Thanks. That seems like the best route. Change the whole cable out. It will run me $39.94 with shipping for the 10' cable plus $29.50 for the 4' tray cable = $69.44

This will be a total of 14' now, but seeing that I am using 10 awg and not 12/14 awg I shouldn't lose any current correct? Could I extend it even further if I use 10 gauge and if so how far without losing current?
Plus, if I remove and replace the total length of cable do I need to add a fuse?

thanks
Paul

I don't remember a fuse with the original. As long as you are buying new cable, you might as well go longer. Mine was 15' and the tray cable added a couple of feet, but 10 more feet would have been better to get the panels out in the sun from a shady campsite. If you are going from 12 gauge to 10 gauge, that may make up for the distance loss.

red31 wrote:
One could also use the design your own to build the tray cable.

That may cost less. What terminal rings would I choose, I have 2 6V Interstate Deep Cycle batteries?

red31 wrote:
Try this, use the previous linked tray cable with grey sb50
https://www.batterystuff.com/battery-cables-connectors-plugs/custom-made-cable-sets/10ga4ringSB.html

go to design your own cable http://www.powerwerx.com/adapter-cables/design-build-your-own-custom-cable.asp
pick left 50A sb50
pick grey
pick 10g red/black bonded, 10' or so
pick bare ends ($30) and wire the bare end into the charge control batt +/-

I believe your existing wire is 12g and would not crimp well with a SB50 10g barrel.

Thanks. That seems like the best route. Change the whole cable out. It will run me $39.94 with shipping for the 10' cable plus $29.50 for the 4' tray cable = $69.44

This will be a total of 14' now, but seeing that I am using 10 awg and not 12/14 awg I shouldn't lose any current correct? Could I extend it even further if I use 10 gauge and if so how far without losing current?
Plus, if I remove and replace the total length of cable do I need to add a fuse?

thanks
Paul

One could also use the design your own to build the tray cable.