Do I need a battery isolator?
Thread Starter
|
Mountain Pass
Joined: Oct 2020
Posts: 107
Likes: 5
From: Dothan, AL
Do I need a battery isolator?
I’ve just graduated from a bumper pull to a 5W (GD 303RLS - 33’). The manual suggest installing a battery isolator “to independently charge both the RV auxiliary battery and the tow vehicle battery” and to “prevent the RV from draining your tow vehicle battery”. Why? My tow vehicle is a 2020 F250 6.7 diesel with dual batteries. Is it because the RV fridge is now 12v instead of the Dometic LP gas/120v like we had in the previous RV? Is the alternator output insufficient to run the new fridge while towing? Been towing for years but this is new to me. Thanks
Super Moderator
Joined: Aug 2008
Posts: 37,379
Likes: 1,863
From: Frederick, MD
No need. With the truck off the pcm does not allow current through the 7 pin.
When parked, disconnect from the 5th wheel anyway since you are at your destination.
We travel cross country and will stay at Walmarts and such. For those I don't disconnect. No issues since current is not allowed to pass thru the 7 pin.
When parked, disconnect from the 5th wheel anyway since you are at your destination.
We travel cross country and will stay at Walmarts and such. For those I don't disconnect. No issues since current is not allowed to pass thru the 7 pin.
Logistics Pro
Joined: Apr 2000
Posts: 4,334
Likes: 306
From: Mills River
I’ve just graduated from a bumper pull to a 5W (GD 303RLS - 33’). The manual suggest installing a battery isolator “to independently charge both the RV auxiliary battery and the tow vehicle battery” and to “prevent the RV from draining your tow vehicle battery”. Why? My tow vehicle is a 2020 F250 6.7 diesel with dual batteries. Is it because the RV fridge is now 12v instead of the Dometic LP gas/120v like we had in the previous RV? Is the alternator output insufficient to run the new fridge while towing? Been towing for years but this is new to me. Thanks
Many of us have found there’s limited voltage and current available from the 7-pin connector’s trailer battery charge circuit due to small wire size. You may be able to run the fridge on 12V, or you may be able to (partially) charge the trailer house batteries, but you’ll likely not be able do both simultaneously.
If you want to do both, you might consider a separate high-amp / large AWG circuit from the truck to the camper batteries, preferably via a DC-DC charger located in the camper.
HTH,
Jim / crewzer
Thread Starter
|
Mountain Pass
Joined: Oct 2020
Posts: 107
Likes: 5
From: Dothan, AL
Thanks for all the info. I didn’t mention that the RV came with a 165W solar panel that trickle charges the RV battery. My assumption is that I would have to add panels to keep the fridge running during a 2-day, 1000-mi trip. Am I over thinking this?
Super Moderator
Joined: Aug 2008
Posts: 37,379
Likes: 1,863
From: Frederick, MD
No the truck will covey enough power to keep the fridge running and charge the battery while driving.
Is the fridge 12V and propane capable? I run mine on propane until plugged into shore power.
Is the fridge 12V and propane capable? I run mine on propane until plugged into shore power.
Tuned
Joined: Feb 2020
Posts: 324
Likes: 115
The 303's with a solar package get the 12 volt compressor fridge. Not the absorption fridge like the old days. It pulls about 6 amps DC when the compressor is running.
Trending Topics
Tuned
Joined: Feb 2020
Posts: 324
Likes: 115
I’ve just graduated from a bumper pull to a 5W (GD 303RLS - 33’). The manual suggest installing a battery isolator “to independently charge both the RV auxiliary battery and the tow vehicle battery” and to “prevent the RV from draining your tow vehicle battery”. Why? My tow vehicle is a 2020 F250 6.7 diesel with dual batteries. Is it because the RV fridge is now 12v instead of the Dometic LP gas/120v like we had in the previous RV? Is the alternator output insufficient to run the new fridge while towing? Been towing for years but this is new to me. Thanks
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
Hotshot
Joined: Jan 2010
Posts: 10,060
Likes: 491
From: Bristol, TN.
And the compressor is not running constantly once the fridge is cooled down so with solar on the roof while running down the road with the truck there should be no problem. The greater issue may be if not on the shoreline with cloudy days and a lengthy stay. May well depend on how rig is used.
Thread Starter
|
Mountain Pass
Joined: Oct 2020
Posts: 107
Likes: 5
From: Dothan, AL
Thanks for the education guys! This is a great site. I hope to contribute more than I get as i get past the newby stage of diesel driving and FW towing. Many years of gas and bumper-pull. Old dog…new tricks.
Tuned
Joined: Feb 2020
Posts: 324
Likes: 115
Glad we could help.
Thread
Thread Starter
Forum
Replies
Last Post