Reply
 
Thread Tools Display Modes
Old 09-23-2019, 08:46 AM   #1
Junior Member
 
Join Date: Aug 2018
Posts: 29
Merging solar controller output with stock rv converter output (splicing).. good idea?

Hi everyone.
Looking to add solar to my RV and I seem to remember seeing a youtube video where the person was splicing the output lines coming from the charge controller with the 12 volt output lines coming from the rv stock converter. That would allow for using the existing wiring and providing two sources of power for recharging the batteries, if needed.
I was looking at turning off the rv converter altogether (using the breaker) and letting the charge controller take care of the batteries (bulk/float), everything. I have enough battery storage. Then, if I'm running into two or more days of shade, then I would turn back on the breaker for the converter (shore power) and let it recharge the batteries for a bit. Thoughts?
__________________

montelovers is offline   Reply With Quote
Old 09-23-2019, 09:11 AM   #2
Senior Member
 
Join Date: Aug 2016
Posts: 1,359
Usually that wiring is pretty small. Probably better to go straight to the batteries.

Also, no reason to turn converter off...
__________________

aeblank is online now   Reply With Quote
Old 09-23-2019, 09:20 AM   #3
Site Team
 
Flybob's Avatar
 
Join Date: Oct 2014
Posts: 10,197
Many of the battery charging devices used in RVs today control the charge by measuring the voltage of the battery(s). You can have two charging devices connected in parallel. If they are both producing the same charging voltage you will get approx twice the charging current. If however the two chargers produce different charging voltages you will get less than twice the charging current as the higher voltage charger will fool the lower voltage charger into thinking the battery is actually at a higher charge state than it is.
__________________

2015 Freedom Express 248RBS
TV 2015 Silverado HD2500 Duramax
TST Tire Monitors
Honda 2000I + Companion
2 100W solar panels
Flybob is offline   Reply With Quote
Old 09-23-2019, 10:48 AM   #4
Senior Member
 
Join Date: Mar 2014
Location: Mountain Foothills of Southern Alberta
Posts: 1,127
Tying in into the existing 12v lines will work just fine. As said previous, no need to turn off the converter.
__________________

2007 Surveyor SV230
- 200 Watts Solar/MPPT Controller - 230 AH Battery Bank - 600 watt PSW Inverter - (2) 2000 watt Inverter Generators - LED Lighting
2009 F150 - 5.4 Litre - Tow Package
Boon Docking 99% of the time.
boondocking is online now   Reply With Quote
Old 09-23-2019, 09:52 PM   #5
Senior Member
 
Join Date: May 2012
Posts: 715
Tying into the battery charge lines from the converter is the equivalent of hooking the wires from the solar panel directly to the battery with a little added wire resistance. There's nothing "wrong" with this but there could be some effects. A direct connection means that you are not using a solar controller between the panels and the battery. It follows from this that the output voltage from the panel will equal the battery voltage. A 12V panel produces its maximum output power when the output panel voltage is usually somewhere between 16 and 19 volts. It's the power that determines how quickly the panel can charge the battery.



Panel manufacturers have charts showing output current and power vs load for their panels. these charts always have a peak power point where the panel produces its rated output power, measured in watts. MPPT controllers are designed to adjust the current draw from the panel to whatever rate necessary to make the panel produce its maximum power. The newest controllers then feed this power to the battery at the voltage that maximizes the current flowing into the battery. It's the current that actually recharges the battery. Don't forget that as a battery charges, the voltage across the terminals rises. The newest MPPT controllers compensate for this while maintaining the three phase charging cycle.


Phil
pmsherman is offline   Reply With Quote
Old 09-24-2019, 06:46 AM   #6
Junior Member
 
Join Date: Aug 2018
Posts: 29
PMSHERMAN... if you read the 'title', I'm just asking if connecting the output of the solar charge controller and splicing it with the output line from the converter going to the battery is ok. So, yes, I do intend on having a charge controller between the solar panel and the rv stock converter. But thank you for the response though.
montelovers is offline   Reply With Quote
Old 09-24-2019, 09:44 AM   #7
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 2,448
You can connect your charge controller output to the converter lugs, in fact, if you have a PD converter there are two lugs for pos and two for neg so you can use the spare connection points.

HOWEVER, in many FR products, the converter first goes to the DC panel and then to the batteries through a disconnect switch. This means that if you turn off your batteries for storage, the solar system will not be able to keep you batteries charged during storage.
__________________

__________________

2015 335DS
ScottBrownstein is offline   Reply With Quote
Reply

Tags
controller, converter, solar

Thread Tools
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



» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 11:08 AM.


×