Thread Tools Search this Thread Display Modes
Old 12-29-2015, 10:56 AM   #1
3 Rivet Member
PecanMan5's Avatar
2015 25' Flying Cloud
Currently Looking...
Hahira , Georgia
Join Date: Dec 2014
Posts: 103
20w solar charger

I purchased a 20w solar battery charger thinking that it would not overcharge like the onboard converter is accused of. I checked the voltage with a multimeter and it was as 17.5v. The internet information says the output is up to 21v. Without getting into a lot of electrical theory, are these high voltages doing the same?

From my Pecan Tree
PecanMan5 is offline   Reply With Quote
Old 12-29-2015, 01:19 PM   #2
Rivet Master
1974 31' Sovereign
1979 23' Safari
Wayland , New York
Join Date: Jan 2012
Posts: 1,178
Images: 3
Directly output from the solar panel that's pretty normal voltage. You need to put a solar charge controller between the solar panel and 12v system in the trailer. It steps down the voltage from the panel to the necessary voltage for 12v load and battery charging. Since it's just a 20w panel you'll be able to get a basic one fairly cheap.

Just reread, is it a integrated all in one solar battery charger and not just a solar panel. If so that may be normal for its operation when not connected to a battery. Indicating a no load voltage output. Connect to battery and see how it functions once the battery is fully charged.

HiJoeSilver is online now   Reply With Quote
Old 12-29-2015, 01:22 PM   #3
Rivet Master
1974 Argosy 20
2014 20' Flying Cloud
Kooskia , Idaho
Join Date: Jul 2009
Posts: 4,592
The voltage you measured is the open circuit voltage. When attached to a battery it will drop much closer to the battery voltage, even with no charge controller (which in reality you should have anyway).

A 20 watt panel will produce so little output that you probably will never have a situation where you overcharge the battery anyway. Slightly over an amp of charge current max, a few hours a day in unlikely to cause you any issues.
idroba is offline   Reply With Quote

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
Converter/Charger vs. Inverter/Charger moosetags Batteries, Univolts, Converters & Inverters 5 11-22-2013 10:21 PM
Solar Battery Charger Cstar Generators & Solar Power 2 01-04-2005 11:59 AM
Solar Charger Sneakinup Generators & Solar Power 1 10-07-2003 09:04 AM
Solar trickle charger.... drboyd Generators & Solar Power 27 09-20-2003 07:51 PM
Adding charger where no charger has gone before Jabba Electrical - Systems, Generators, Batteries & Solar 4 03-08-2003 09:39 AM

Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 01:20 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.