Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 02-22-2017, 11:46 PM   #1
Junior Member
 
Join Date: Feb 2017
Posts: 18
How do I hook up a solar panel to my coach batteries?

I have two deep cycle 12 volt batteries for the coach & want to hook up a 40 watt panel. Just to keep the batteries charged up when the motor-home is stored with no source of outside power. Do I attached to (+) red on one battery then (-) black on the second battery so both batteries are being charged equally? Thanks for your help......Len
LGClarke is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 02-23-2017, 12:34 AM   #2
Senior Member
 
Join Date: Oct 2014
Posts: 119
If your panel doesn't have a built in charge controller, you'll need to buy one so you don't send too much voltage and so it can shut off when the batteries are charged. You can get one on amazon for $10-$20 that would be sufficient for a 40w panel.
__________________
'03 Newmar KSDP 3703 • Magnum MSH-3012 • Magnum PT-100 • GS 160w x 6 • 655 AH
Mike Bartelt is offline   Reply With Quote
Old 02-23-2017, 03:40 AM   #3
Senior Member
 
Tiffin Owners Club
Appalachian Campers
Mid Atlantic Campers
Coastal Campers
Freightliner Owners Club
Join Date: Jan 2015
Posts: 1,622
To answer your question on the battery connections, I'd suggest making the connection on the buss bar, to avoid having multiple wires at the battery connections. Then by default, the connection is spread correctly on the batteries (not that it matters much with little charge current).

If you have to go with attaching at the batteries, it's not a lot of current so really isn't going to matter that the + is on one battery, and the - is on the other battery. Do it where you can get good clean connections and the wires won't rub/fray.
__________________
DaveB, Raleigh, NC
2015 Tiffin RED 33AA, w/Honda CRV
VMSpc, Magnum BMK/ARC50
Kiawah is offline   Reply With Quote
Old 02-23-2017, 06:32 AM   #4
Senior Member
 
Join Date: Mar 2009
Location: Apollo Beach & Key West , FL
Posts: 3,803
Quote:
Originally Posted by Mike Bartelt View Post
If your panel doesn't have a built in charge controller, you'll need to buy one so you don't send too much voltage and so it can shut off when the batteries are charged. You can get one on amazon for $10-$20 that would be sufficient for a 40w panel.
That's what I did --- I put a 40w on the roof of the storage building and ran the wires to the controller then into the chassis batteries.
__________________
2013 DS 4338
2015 F-150 toad with kayaks,bicycles and a Harley in the back
PanJH is offline   Reply With Quote
Old 02-23-2017, 07:11 AM   #5
Senior Member
 
OLYLEN's Avatar
 
Monaco Owners Club
Join Date: Jan 2008
Location: Olympia, Wa
Posts: 2,772
At 40 watts you don't need a controller. At most you will get 2-3 amps to the batteries. You, if the batteries are off(disconnected) will at most maintain not charge. At 100 watts I would add a controller. Red on one battery and black on the other would balance both batteries.

LEN
__________________
2004 Clss C 31' Winnebgo
OLYLEN is offline   Reply With Quote
Old 02-23-2017, 09:11 AM   #6
Senior Member
 
billdreamlv's Avatar
 
Tiffin Owners Club
Join Date: Jul 2014
Posts: 487
Quote:
Originally Posted by OLYLEN View Post
At 40 watts you don't need a controller. At most you will get 2-3 amps to the batteries. You, if the batteries are off(disconnected) will at most maintain not charge. At 100 watts I would add a controller. Red on one battery and black on the other would balance both batteries.

LEN
Len has it right. And to go one step further, the panel will act like a drain when connected to the batteries directly without the sun. This is one of the reasons for the charge controller. If you want to do it right, get two panels about 235 watts a piece and hook them up in parallel to a charge controller and relax. I looked on my local Craigslist and found panels for $90. Otherwise, when you hook them up to the batteries, without the charge controller, you might do as much harm as good.

The most absurd work of a solar panel-discharging a battery |
__________________
Bill & Mary USN 69-73 ASW Technician, MBA.
2006 Tiffin Allegro Bus QDP 1060 watts solar
2012 Jeep Grand Cherokee '16 Polaris Razor 4
billdreamlv is offline   Reply With Quote
Old 02-23-2017, 09:20 AM   #7
Senior Member
 
Join Date: Jul 2014
Posts: 35,317
Quote:
Originally Posted by billdreamlv View Post
Len has it right. And to go one step further, the panel will act like a drain when connected to the batteries directly without the sun. This is one of the reasons for the charge controller. If you want to do it right, get two panels about 235 watts a piece and hook them up in parallel to a charge controller and relax. I looked on my local Craigslist and found panels for $90. Otherwise, when you hook them up to the batteries, without the charge controller, you might do as much harm as good.

The most absurd work of a solar panel-discharging a battery |
From your article,

Most of the solar panels produced today have a series diode to block the discharge of the battery.*

You would probably have look hard to find one that doesn't.

This is a non issue.
twinboat is offline   Reply With Quote
Old 02-23-2017, 09:55 AM   #8
Senior Member
 
billdreamlv's Avatar
 
Tiffin Owners Club
Join Date: Jul 2014
Posts: 487
Quote:
Originally Posted by twinboat View Post
From your article,

Most of the solar panels produced today have a series diode to block the discharge of the battery.*

You would probably have look hard to find one that doesn't.

This is a non issue.
"This is a non issue" because you know for a fact that the 40 watt inexpensive panels have diodes built into them? And your electronic credentials are? Sometimes reading information from people who don't have a clue about electronics can really be damaging to your coach.
__________________
Bill & Mary USN 69-73 ASW Technician, MBA.
2006 Tiffin Allegro Bus QDP 1060 watts solar
2012 Jeep Grand Cherokee '16 Polaris Razor 4
billdreamlv is offline   Reply With Quote
Old 02-23-2017, 10:12 AM   #9
Senior Member
 
Join Date: Jul 2014
Posts: 35,317
Don't know for a fact. Yes It is a non issue.


BLOCKING AND BYPASS DIODES

Many older books and articles recommend using blocking diodes to prevent reverse current flow back through the panel at night ("dark current"). Many others do not (including us, mostly). It actually depends on the situation, but as a general rule in 12 volt systems, you will lose more power from diode losses than you will from leakage back into the panel at night. The situation gets much worse at higher temperatures with crystalline panels. All regulators (charge controls) have built-in blocking circuits. About the only case where a blocking diode might be needed is with small thin-film panels, such as the Unisolar US-5 or Siemens ST5, where the panel is connected directly to the battery. Diode losses are much less in higher voltage systems, such as 48 volts.
twinboat is offline   Reply With Quote
Old 02-23-2017, 01:39 PM   #10
Senior Member
 
billdreamlv's Avatar
 
Tiffin Owners Club
Join Date: Jul 2014
Posts: 487
Quote:
Originally Posted by twinboat View Post
Don't know for a fact. Yes It is a non issue.


BLOCKING AND BYPASS DIODES

Many older books and articles recommend using blocking diodes to prevent reverse current flow back through the panel at night ("dark current"). Many others do not (including us, mostly). It actually depends on the situation, but as a general rule in 12 volt systems, you will lose more power from diode losses than you will from leakage back into the panel at night. The situation gets much worse at higher temperatures with crystalline panels. All regulators (charge controls) have built-in blocking circuits. About the only case where a blocking diode might be needed is with small thin-film panels, such as the Unisolar US-5 or Siemens ST5, where the panel is connected directly to the battery. Diode losses are much less in higher voltage systems, such as 48 volts.
When you plagiarize someone else's work you should at least give them credit. I believe you copied this website for your insight.

https://www.solar-electric.com/solar...cal-tips.html/

"About the only case where a blocking diode might be needed is with small thin-film panels, such as the Unisolar US-5 or Siemens ST5, where the panel is connected directly to the battery."

From your own quote.
__________________
Bill & Mary USN 69-73 ASW Technician, MBA.
2006 Tiffin Allegro Bus QDP 1060 watts solar
2012 Jeep Grand Cherokee '16 Polaris Razor 4
billdreamlv is offline   Reply With Quote
Reply

Tags
batteries, panel, solar, solar panel



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Solar panel operation/hook-up toocantravel Newmar Owner's Forum 2 09-06-2013 06:26 PM
Chassis Battery Solar Solar Panel camperkids Newmar Owner's Forum 8 07-12-2013 02:14 PM
need advice on solar panel hook up RCtime Going Green 2 05-19-2013 06:43 PM
Solar Panel Hook-Up How To gotwood Travel Trailer Discussion 1 06-09-2012 11:07 AM
Solar Panel Hook-Up adavid7980 MH-General Discussions & Problems 7 07-29-2009 11:51 AM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 03:38 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.