Adding Solar - is there conflict with shore power transformer? - Fiberglass RV


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-07-2020, 12:50 PM   #1
Nik
Senior Member
 
Nik's Avatar
 
Name: Nik
Trailer: BigFoot
Colorado
Posts: 101
Adding Solar - is there conflict with shore power transformer?

I have secured a 200w PV panel to my roof. I can tunnel down to the "fuse box" where there is also a transformer and some kind of onboard factory trickle charger. I have a quality charge controller and inline fuse.

What about competing charging systems?

1. Is there a conflict between the on board transformer supplying a charge to the batteries and the solar system doing the same - at the same time?

2. What about the tow vehicle battery? The truck alternator usually charges the house batteries, too. Will that system conflict with the solar or will the solar charge the truck battery?

I've been told to install a switch to shut off the solar when I'm plugged into shore power. (I'll forget, does it matter if I forget?)


I know I can isolate the truck battery from the trailer. Mostly I unplug when camping.

I've read some books and online and somehow this question is just overlooked. Perhaps I'm thinking too much. Maybe just hook it up and go and there's no problem!?

Thanks in advance.
__________________

Nik is offline   Reply With Quote
Old 07-07-2020, 01:01 PM   #2
Senior Member
 
Alex Adams's Avatar
 
Name: Alexander
Trailer: 1979 Boler B1300
New Hampshire
Posts: 694
I'm assuming you have a solar charge controller hooked up to your panels. If you don't, get one. Connecting panels directly to the battery can overcharge the battery. I have run both a solar charge controller and an AC charger at the same time with no apparent ill effects.
__________________

Alex Adams is offline   Reply With Quote
Old 07-07-2020, 01:14 PM   #3
Nik
Senior Member
 
Nik's Avatar
 
Name: Nik
Trailer: BigFoot
Colorado
Posts: 101
Yes, thank you. I edited my post to say I have a full solar system with charge controller. Thanks.
Nik is offline   Reply With Quote
Old 07-07-2020, 01:22 PM   #4
Senior Member
 
Alex Adams's Avatar
 
Name: Alexander
Trailer: 1979 Boler B1300
New Hampshire
Posts: 694
Cool! I also forgot to mention that I have plugged the seven way in with the car running and the solar controller connected and have not had an issue. Sometimes I camp where everything is partially shaded so I use my tow vehicle to put some extra juice in the battery.
Alex Adams is offline   Reply With Quote
Old 07-07-2020, 01:40 PM   #5
Senior Member
 
ZachO's Avatar
 
Name: Zach
Trailer: 91 Bigfoot 17
Montana
Posts: 2,337
Registry
Technically both the charge controller and power center charger should be sensing the state of the battery and choosing their state accordingly, so if they're both functional (not a given with old camper chargers), they shouldn't do any damage.
ZachO is offline   Reply With Quote
Old 07-08-2020, 01:05 PM   #6
Member
 
Name: Martin
Trailer: 1993 CASITA 16SD
Texas
Posts: 55
I've been running such a system for four years and not had a problem.
CASITA BANANA is offline   Reply With Quote
Old 07-18-2020, 02:44 AM   #7
Senior Member
 
Name: Elliott
Trailer: Bigfoot
Everywhere
Posts: 257
Generally you can treat the 12V system like one big bus with power simultaneously going in and out from various places without any problems. It's possible you'll make suboptimal use of the solar if it detects the shore charger and backs off to float mode instead of running in bulk, but that's about the worst-case scenario. Maybe if you have a really small battery and the combined solar/vehicle/converter current's too high, but at least one of them's going to see the higher voltage and back off.

I would not shut off the solar while plugged in. In addition to being unnecessary, disconnecting the controller<->battery connection while panels are still connected to the controller can damage at least some controllers.
Defenestrator is offline   Reply With Quote
Old 07-25-2020, 04:20 AM   #8
Junior Member
 
Name: DAN
Trailer: CASITA SPIRIT
California
Posts: 12
I recently installed an InteliPower converter-charger and asked the factory the same question. They indicated to connect the solar panel controller Directly To The Battery and NOT to the converter-charger panel. All your electrical sources need internal controllers to sense battery conditions to prevent overcharging. I actually turn my converter-charger Off when boondocking on Solar to lower any amp draws. I usually need to charge batteries once a week on generator without adequate sun. The only caution is your vehicle alternator connection. Your trailer Can and Will draw down your Start Battery to the same voltage.
Either disconnect the trailer-vehicle or install an ignition auto-disconnect solenoid to avoid a Dead Start Battery !
CHICO DAN is offline   Reply With Quote
Old 07-25-2020, 10:16 AM   #9
Senior Member
 
Perryb67's Avatar
 
Name: Perry
Trailer: 2018 Escape 5.0
Lanesboro, Minnesota, between Whalan and Fountain
Posts: 238
Quote:
Originally Posted by CHICO DAN View Post
I recently installed an InteliPower converter-charger and asked the factory the same question. They indicated to connect the solar panel controller Directly To The Battery and NOT to the converter-charger panel. All your electrical sources need internal controllers to sense battery conditions to prevent overcharging. I actually turn my converter-charger Off when boondocking on Solar to lower any amp draws. I usually need to charge batteries once a week on generator without adequate sun. The only caution is your vehicle alternator connection. Your trailer Can and Will draw down your Start Battery to the same voltage.
Either disconnect the trailer-vehicle or install an ignition auto-disconnect solenoid to avoid a Dead Start Battery !
👍 👍 👍

Perry
Perryb67 is offline   Reply With Quote
Old 07-25-2020, 09:20 PM   #10
Member
 
Trailer: Casita 16 ft
Texas
Posts: 53
Charging from vehicle

Most newer vehicles have a relay that shuts off charge to the trailer battery line. You can check that with a voltmeter connected to the battery in the trailer. First check voltage with tow vehicle running, then turn it off.
Should be 13.5v running then 12.6v off. (approximate)
Friz is offline   Reply With Quote
Old 07-26-2020, 12:57 PM   #11
Senior Member
 
Name: K C
Trailer: 1971 Trailswest Campster
Washington
Posts: 2,912
the solar wiring hooks directly to the battery. The positive wire has its own fuse. It never connects into the wiring for the power converter.



Go to a marine supply store. You can get a fitting that goes onto the battery positive battery lug that provides a place to attach and fuse the positive wire from the solar.
__________________

k corbin is offline   Reply With Quote
Reply

Tags
solar


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
Adding Solar to Bigfoot Roof ZachO Modifications, Alterations and Updates 137 07-23-2019 11:35 AM
Adding 50W Solar panel to a Scamp 19' jpalm Modifications, Alterations and Updates 0 07-01-2017 06:41 PM
Adding Solar in Houston Whec716 Electrical | Charging, Systems, Solar and Generators 2 08-20-2012 10:55 AM
Adding Solar Panels Bigfoot Mike Problem Solving | Owners Helping Owners 50 09-25-2009 08:59 PM
Solar Panel Connetion adding a controller too... jimtesla Electrical | Charging, Systems, Solar and Generators 16 09-22-2009 06:40 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 08:45 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
×