# How far away from the battery can I locate a 10 watt solar panel..



## red1 (Jun 19, 2007)

And still have effective charging for a 12 volt battery? Mighty mule has a circuit on the control board to regulate charging.."Sleep draw" is 25mA and "Active draw"is 2 to 5 amps..
Asked m.m. if for purposes of good sun exposure I could put the panel 50 feet from the controller...Said no problem, just keep it in the sun...16 gauge, stranded, direct burial dual conductor low voltage wire came with the kit..only 10 feet..Shopping for more and one seller of another gate opener..ghost I believe..said not to put it, the solar panel, more that 20 feet away from the battery or you would have to add another panel...At 100+ bucks each, I'm trying to avoid that...There are some online voltage drop calculators, which I don't have a clue how to work...Thx..


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## Bearfootfarm (Jul 13, 2006)

Closer is always better.
You may get more answers reading here:
https://www.solarpaneltalk.com/forum/off-grid-solar/batteries-energy-storage


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## TnAndy (Sep 15, 2005)

Voltage drop calculators aren't hard to use, but you need the right numbers to input.

This one, for example: https://www.calculator.net/voltage-drop-calculator.html

Enter the wire type, wire size (use 12ga for example, you can enter others), the voltage (use 17v....a 12v solar panel typically puts out 17-18v no load), phase (use DC), then your distance, leave the amp load at 1 and hit 'calculate'. You'll see at 50', the drop is minor, using 12g wire.

Even if you quadruple the amp load to 4, still less than a volt drop. You just don't want to go below 14, or you won't have enough volts to charge a 12v battery.

My concern would be more the low charging amps you're gonna put out (less than one) with a 10w panel. Given you'll probably only get decent sun 5-6hrs a day (and on sunny days), that's not a lot of trickle to charge with. Thing is, you may go a LONG time with the battery in a semi-depleted state before a problem (like it doesn't work anymore) shows up....and ruin a battery in the process.

A one amp charger running 24hrs/day might do fine.....but I be suspect of one running 6hrs/day. Of course, it would also depend on how many cycles of the opener you use. 

I have two different batteries on solar chargers....one I use a 40w (gets real good sun), the other a 50w (not as good sun), and never have a problem with them. Excess capacity is always better than not enough.


Do a little shopping and you'll find panels ain't all that expensive.....here for example is a 40w for $69 w/free shipping. How much is a new battery ?


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## Nimrod (Jun 8, 2010)

red1 said:


> said not to put it, the solar panel, more that 20 feet away from the battery or you would have to add another panel...At 100+ bucks each, I'm trying to avoid that.


Sounds like the 10 watt panel is $100. If you go on Ebay you can buy a 100 watt panel for under $100 with free shipping.

I set up my summer camp with a 100 watt panel ($90), a 30 amp charge controller ($30), 50 feet of #10 wire with MC4 connectors ($30), a marine deep cycle battery ($70), Fuses ($3), and a hunk of 10 ga. wire I had on hand. Total $223. 

I ran a 29 watt TV/DVD about 2 hours a night and a 13 watt led light about an hour a night. The battery was always fully charged by late afternoon the next day.


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## red1 (Jun 19, 2007)

Bearfootfarm said:


> Closer is always better.
> You may get more answers reading here:
> https://www.solarpaneltalk.com/forum/off-grid-solar/batteries-energy-storage


 I went there and registered...Haven't the ability to post or reply to posts...subscribe?
Wondering if it is strictly facebook or tweet communication..of which I do either..


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## Bearfootfarm (Jul 13, 2006)

red1 said:


> I went there and registered...Haven't the ability to post or reply to posts...subscribe?


I don't know if it's automatic or if you have to wait for some sort of approval.
I just read a lot of stuff there and most of the time it's easy to find some answers.


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## red1 (Jun 19, 2007)

TnAndy said:


> Voltage drop calculators aren't hard to use, but you need the right numbers to input.
> 
> This one, for example: https://www.calculator.net/voltage-drop-calculator.html
> 
> ...


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## red1 (Jun 19, 2007)

Thanks...Got similar numbers using a 16 wire size..At the location I want to place the panel....summer, 6 - 10 hrs sun ..winter will be around 6 - 8. The opener is way big for my gate...good for a 16 foot long 500 # plus...mine is 12 foot and maybe 50 - 60 #..
Rarely use the gate more than once a day...Stays open the rest of the time...A half foot trencher is 45$/hr..and I plan on, per the directions..putting the line in a pvc water line...


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## wy_white_wolf (Oct 14, 2004)

red1 said:


> I went there and registered...Haven't the ability to post or reply to posts...subscribe?
> Wondering if it is strictly facebook or tweet communication..of which I do either..


I'm member there. We've had a few problems with spammers so they do have things locked down tight for newbies. So keep trying. I do now you won't be able to post a link until after you've made so may posts and the first few have to be approved by an admin.

WWW


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## wy_white_wolf (Oct 14, 2004)

Bearfootfarm said:


> I don't know if it's automatic or if you have to wait for some sort of approval.
> I just read a lot of stuff there and most of the time it's easy to find some answers.


From there "New Members Thread":

"
Hi All,

At the moment all new member registrations are being sent for moderation, that just means they cant post until they have been approved. This is being trialed to try to slow / stop spammers.

So new members please be patient as it could take anywhere from minutes to hours before you get approved to post. Please remember that posting links in your post will also result in that post being sent to moderation before it is published.

Merry Christmas everybody"


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## JohnP (Sep 1, 2010)

red1 said:


> And still have effective charging for a 12 volt battery? Mighty mule has a circuit on the control board to regulate charging.."Sleep draw" is 25mA and "Active draw"is 2 to 5 amps..
> Asked m.m. if for purposes of good sun exposure I could put the panel 50 feet from the controller...Said no problem, just keep it in the sun...16 gauge, stranded, direct burial dual conductor low voltage wire came with the kit..only 10 feet..Shopping for more and one seller of another gate opener..ghost I believe..said not to put it, the solar panel, more that 20 feet away from the battery or you would have to add another panel...At 100+ bucks each, I'm trying to avoid that...There are some online voltage drop calculators, which I don't have a clue how to work...Thx..


I was thinking 6ga off the top of my head based on my setup from 10 years ago. Here's a wire size calculator. You really don't want more than a 2% drop between the panels and charge controller. http://www.solardesigntools.com/wire_calculator.php

screenshot








If changed to 3%, it recommends 6ga. Yes, with low voltage like 12vdc, you need big wire. Just look at your battery cables on a car going to the starter which is fairly short. 12 volt panels put out 17-21 vdc, not 12vdc. The charge controller takes that 17-21 and reduces it to ideal charging voltages which can be anywhere from just over 12 for a float and up to 14.8vdc.

Changing the distance to 10 feet and the drop to 5% gives 15ga wire(which you would never find) so I imagine they gave you 16ga knowing the panels will never put out the max rating of 10amps, unless you happen to be on the equator, at mid day, during summer soltice and there's a solar flare or something.

This page http://www.affordable-solar.com/wholesale/solar-tools/wire-sizing-charts/ recommends the less than 2%. 

If this was for your house, I would go with 6ga but since it's just a gate opener, I would go with 8-10ga direct burial romex style but since it's super hard to find and super expensive in 8ga, I would go with 10ga but that's $100 so I would cheat a little more and get 12ga for $40.

Being such an occasional use thing, it should be fine because the battery will never get that low anyway. It's not a case where you'll melt the wire either as 12ga is good for 20 amps.
https://www.homedepot.com/p/Southwire-50-ft-12-2-Gray-Solid-CU-UF-B-W-G-Wire-13055922/202316408

If you look at other wiring in a vehicle for high amp items like electric windows, electric seat etc, it's up there in the 10-12ga range. They do that because if the voltage dropped to 11 volts, it would be bad for the electric motor. That's from the battery to the electric load which in your case will be minimal as I assume the battery is close to the gate opener, hence you needing to go 50 foot to the panel.


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## red1 (Jun 19, 2007)

wy_white_wolf said:


> From there "New Members Thread":
> 
> "
> Hi All,
> ...



Think I'll bail from the site...too much personal information wanted...maybe later...thx for the info...


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## red1 (Jun 19, 2007)

The mighty mule is up and running...10 watt solar panel putting out 18 + volts.


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## red1 (Jun 19, 2007)

Actually..had the multimeter on the wrong acv


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