RV Trip Planning Discussions

Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > RV Systems & Appliances
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 12-13-2019, 07:08 PM   #1
Senior Member
 
SeeTheUSA's Avatar
 
Winnebago Owners Club
Join Date: Apr 2005
Location: Texas
Posts: 1,812
How many watts to keep batteries up?

Our rig gets stored away in a covered building that has no electrical, so my rooftop solar panels canít contribute to keeping my batteries charged. The View has two 12 volt coach batteries and thereís a Tik-L-Start to keep the chassis battery up.

I can set up a portable solar panel to maintain the batteries while in storage. It would get direct sunlight until about noon, then daylight for the rest of the day. No appliances or such need to be running.

Any estimate on what size solar panel I should consider? Thanks.
__________________

__________________
Warren and Debbie, Deep in The Heart of Texas
2018 Winnebago View 24D
2014 Tiffin Breeze 32BR, 2012 Winnebago Navion 24G, 2006 Winnebago View 23H
SeeTheUSA 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 12-13-2019, 07:36 PM   #2
Senior Member
 
450Donn's Avatar
 
Join Date: Jun 2006
Location: Dallas,OR
Posts: 3,809
You might be better off taking the batteries home and hook them to a trickle charger.
If you choose solar start with a 100 watt. As a trickle charger that should do. Remember battery abilities go down as temps go down.
__________________

__________________
Don and Lorri
Resident Dummy.
450Donn is offline   Reply With Quote
Old 12-14-2019, 08:59 AM   #3
Senior Member
 
Winnebago Owners Club
Workhorse Chassis Owner
Join Date: Nov 2018
Posts: 437
There's the amount of power the batteries need to make up for self discharge but another variable that you'd have to know is what other loads may be present drawing them down. You'd have to measure that, since there's no way anyone else could predict it.

Since you only have half a day of sun and unknown panel tilt you need "more" than if it were a panel in full sun.

All of that being said what I'd do is get more panel than you think you need, and incorporate a charge controller. Then you're covered for some less than optimum charging days and whatever phantom loads are present, rather than to try and critically size a directly connected panel for the insolation and loads you have.

Simpler would be to give them a full charge and disconnect but not sure if that's an option for what you're trying to do.

Mark B.
Albuquerque, NM
Mark_K5LXP is offline   Reply With Quote
Old 12-14-2019, 09:27 AM   #4
Senior Member
 
spdracr39's Avatar


 
Monaco Owners Club
Join Date: Jul 2016
Location: Cabot, Arkansas
Posts: 2,540
I have 4 6v t105's and my 150 watt panel has no trouble keeping the batteries up when parked between trips if it is sunny everyday. More than a couple days of clouds and things start changing. It seems like my monitoring panel says I have a 3 or 4 amp (about 50 watts) parasitic draw when everything is off. Of course that includes the monitor itself.
__________________
2004 Beaver Monterey Laguna IV
Cummins ISC 350HP Allison 3000 6 speed
2020 Chevy Equinox Premier 2.0t 9 speed AWD
https://enjoying-life.net
spdracr39 is online now   Reply With Quote
Old 12-14-2019, 09:40 AM   #5
Senior Member
 
jacwjames's Avatar
 
Monaco Owners Club
Join Date: Jun 2014
Posts: 6,030
My coach came with a 85 watt solar panel from the factory and PO installed 2 more 125 watt panels so I have 335 watt total.

Even with this it will not keep up with the parasitic draw if I leave the salesman switch on but I can leave the battery disconnect switchs connected.

If you have battery disconnect switch a 100 watt panel should work, maybe less.
__________________
Jim J
2002 Monaco Windsor 38 PKD
2005 Jeep Grand Cherokee w/5.7 Hemi
jacwjames is offline   Reply With Quote
Old 12-14-2019, 09:53 PM   #6
Senior Member
 
Isaac-1's Avatar
 
Join Date: Jun 2016
Location: SW Louisiana
Posts: 3,916
When this question comes up, I suggest about a 100-130 watt solar panel, these are available in kit form with a solar controller, mounting brackets and 30-40 feet of cable for around $130 online on sites like Amazon. This may be overkill for part of the country that tends to get ample sunlight, like much of Texas, but given it only cost about 1/3 more than a panel half its size, it is cheap insurance in case of extended cloudy weather, poor mounting angle, etc.


See https://smile.amazon.com/ECO-WORTHY-.../dp/B07VJFXBTT or https://smile.amazon.com/HQST-Monocr...dp/B01I0HAKJA/
__________________
2002 Safari Trek 2830 on P32 Chassis with 8.1L
Isaac-1 is offline   Reply With Quote
Old 12-14-2019, 11:33 PM   #7
Senior Member
 
Join Date: Jan 2018
Posts: 913
Quote:
Originally Posted by SeeTheUSA View Post
Any estimate on what size solar panel I should consider? Thanks.
I use one of these for each of my 12 v batteries on my sailboat in the PNW.

https://www.harborfreight.com/15-wat...ger-62449.html

My MH has a 40 watt panel to maintain batteries. Since I am full time I have not tested it.
__________________
Kit & Rita
37 foot Ď98 HolidayRambler Endeavor diesel pusher
followingsea is offline   Reply With Quote
Old 12-14-2019, 11:54 PM   #8
Senior Member
 
gpounder's Avatar


 
Join Date: Nov 2017
Location: Oakhurst, CA
Posts: 471
Recognize there are some loads that are not disconnected. My rig draws about 300 ma so some math, .3x24hrs=7.2ah per day. So I need to replace that used power. Guess what a 100 watt solar panel will provide in 1 hour 7.2 amps but that is in a perfect world without any losses. Say you get 4 hours of really good sun and there is a 30% loss, so you get 20 ah of charge in one day. Basically this shows you a 100 watt panel is plenty of power.
__________________
2007 Country Coach Tribute 260 Sequoia
40' DP w/Cat400, F494513
Live next to Yosemite
Tror Fourwinds Class C, 1961 American Eagle 01 Bus
gpounder is offline   Reply With Quote
Old 12-15-2019, 12:13 AM   #9
Junior Member
 
Join Date: Sep 2019
Posts: 20
My rig is in storage with only a couple of rodent devices running.
A 5 watt panel seems to be keeping my 300AH battery bank in good condition.
__________________
Rick
2019 Grand Design Reflection 150 273MK,
2015 Ford F350 CC SB Lariat Powerstroke, PullRite Superglide
RickLight is offline   Reply With Quote
Old 12-17-2019, 03:16 PM   #10
Senior Member
 
Pappion's Avatar
 
Join Date: May 2018
Location: Scottsdale AZ
Posts: 182
My TT has a battery disconnect circuit breaker. So no parasitic loads in storage. Just battery self discharge issues. My 10W panel is more than enough to bring the 2 size 31 AGMs up to full charge eventually. After that I tuck the panel out of direct sunlight.
This 10W solar maintainer panel does not have a controller. It has a blocking diode.
__________________

__________________
Chalet XL1930 A-Frame 2010
2x size 31 AGM Outback Nano-Carbon
Retired Engineering Technician
Pappion is offline   Reply With Quote
Reply

Tags
batteries



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
How many watts Solar panel do i need? simtec820 Class C Motorhome Discussions 12 06-27-2014 01:16 AM
How many miles are too many for a motorhome? Zoafan Class A Motorhome Discussions 24 01-13-2013 05:57 PM
How Many is Too Many RVGal1 Class A Motorhome Discussions 7 07-05-2012 07:51 PM
How many miles are "too many"? mackerman MH-General Discussions & Problems 11 03-09-2008 09:33 AM
To keep or not to keep? Wallaby Dan Vintage RV's 11 10-24-2006 05:56 PM

» Featured Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 07:02 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×