Rookie Mistake 102 - Fiberglass RV
Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-23-2020, 10:47 PM   #1
Senior Member
 
Name: Lisle
Trailer: 2018 Casita Spirit Deiuxe
Massachusetts
Posts: 181
Registry
Rookie Mistake 102

So I've been full time in my Casita 16' since September. I went thru the RV Online University, RV101 class, and read the Casita manual. Nowhere in there did it mention that I should unplug my camper from my tow vehicle overnight. (Or did I miss it?) Turns out this is critical information: My car died while towing the camper on an interstate in 5 o'clock traffic. I had just enough momentum to get car and camper to the shoulder. There I ran my flashers for 2 hrs waiting for a tow, until the car battery was drained to nothing. (Yes, Good Sam kept me waiting.) The local Toyota dealer found a blown fuse but thought that might not be the whole problem, ie. what made the fuse blow? Couldn't find anything else to fix, so off I went. Drove fine for 2 days. Then I stayed in a Walmart parking lot overnight, with the 7 prong connecting the car to the camper, and running a few things on electricity in the camper. In the morning the car was dead. The battery wouldn't hold a charge so I got a new battery. New battery held charge overnight. Again, set off. Drove all day (both car and camper battery should have been fully charged). Spent the night in a Walmart parking lot, with car and camper connected and running electrical stuff in the camper. This morning, car was again dead. Fortunately the tow guy was able to jump start it. And he told me that yes, leaving the car connected to the camper and running electrical stuff in the camper can drain your car's battery. Finally I understand. So be warned, newbies, and disconnect your car from your camper overnight if you're running electrical things in the camper. In this case, it's been cold here, I was running the electric fan on my propane heater, as well as the water pump and the frig on 12V. Cost me $1400 in repair bills and RV campsites while the car was in the shop. Sighhhhh.
Lisle is offline   Reply With Quote
Old 01-23-2020, 10:59 PM   #2
Senior Member
 
AC0GV's Avatar
 
Name: Kenneth
Trailer: Scamp
Wisconsin
Posts: 1,867
Registry
It depends

[QUOTE=Lisle;766217]So I've been full time in my Casita 16' since September. I went thru the RV Online University, RV101 class, and read the Casita manual. Nowhere in there did it mention that I should unplug my camper from my tow vehicle overnight. (Or did I miss it?)


It will depend on the tow vehicle and who wired it. Many factory wired 7 pins disconnect the "charge" pin when the engine is not running.
Attached Thumbnails
7way12v.jpg  
AC0GV is offline   Reply With Quote
Old 01-24-2020, 12:25 AM   #3
Senior Member
 
Raspy's Avatar
 
Name: John
Trailer: Roamer 1
Smith Valley, Nevada
Posts: 2,880
Lisle,

Everything fits together except why the car died while driving. Once running, the car battery should not go dead.

It is probably not a good idea to ever run the fridge on 12 volts. Not many vehicles send enough power through the seven pin plug to support that, and while plugged in, running it on shore power is better. While out camping, propane is best.
__________________
I only exaggerate enough to compensate for being taken with a grain of salt.
Raspy is offline   Reply With Quote
Old 01-24-2020, 04:01 AM   #4
Senior Member
 
Doug Arthurs's Avatar
 
Trailer: Boler
Posts: 227
Registry
There is an online RV university wow who new. If they don't teach you to unplug when camped overnite then they are not very knowledgeable. If they don't warn you the fridge will suck the charge out of a battery fast then shame on them. What did they teach?
Doug Arthurs is offline   Reply With Quote
Old 01-24-2020, 05:38 AM   #5
Senior Member
 
Jon in AZ's Avatar
 
Name: Jon
Trailer: 2008 Scamp 13 S1
Arizona
Posts: 11,925
Registry
Rookie Mistake 102

They probably assume the vehicle was wired properly with a switch or isolator to protect the tow vehicle battery. Factory 7-pin wiring usually turns off the charge circuit with the ignition. Aftermarket, who knows? Could be a straight line from the battery. It should at least have a fuse.

Even so, disconnecting the umbilical for long stops and overnights is a basic that should have been covered in the hitching/unhitching section. Shame on them.

Running a smaller fridge on 12V while towing is possible, but it requires getting several things right: (1) alternator of sufficient output, (2) charge wire of adequate size, and (3) ignition switch or isolator to prevent draining the battery when the engine isn’t running. Many setups, even factory systems, only support charging the trailer battery, not running a fridge.

If you’re not sure about any of the above, best to leave the fridge off (ice or pre-frozen foods can maintain cooling as long as you don’t open the door) or run on propane when towing (legal except when refueling, on auto ferries, and in some tunnels).

12V electrical should be a whole course of its own. Actually there’s a good primer on this site, “The 12V Side of Life, Parts 1 and 2.” Don’t know if it covers this issue or not.

It would be worth discussing with your mechanic why the vehicle died while running. Agree that requires additional investigation.

Thanks for being vulnerable and sharing your experience, Lisle. It will surely help someone else.

Happy camping!
Jon in AZ is offline   Reply With Quote
Old 01-24-2020, 05:56 AM   #6
Raz
Senior Member
 
Raz's Avatar
 
Trailer: Trillium 2010
Posts: 5,185
Quote:
Originally Posted by Doug Arthurs View Post
There is an online RV university wow who new. If they don't teach you to unplug when camped overnite then they are not very knowledgeable. If they don't warn you the fridge will suck the charge out of a battery fast then shame on them. What did they teach?
How to make S'mores.
Raz is offline   Reply With Quote
Old 01-24-2020, 06:16 AM   #7
Member
 
Trailer: No Trailer Yet
Posts: 79
Keep you frig on propane, and you can even forget to unplug from your trailer overnight.
Jimmy J is offline   Reply With Quote
Old 01-24-2020, 07:54 AM   #8
Senior Member
 
Name: Dave
Trailer: 2013Escape 21
Iowa
Posts: 1,212
Sorry to hear you encountered such an expensive lesson and “ fault “ in your hookup. However, this has happened to a lot of folks. On my 2012 Toyota the folks that installed my 7 pin had it hot all the time. In California I stopped for lunch and a visitors center. In about 30 minutes the car would not start. I got a jump and was ok for the rest of the trip but did hear the starter growl a couple times. Upon returning home I had the vehicle in for routine service where they discovered a “dead cell” in the battery and that I had been running and starting on 10.8 volts. The battery was under warranty so I came out fine and came to the realization that the trailer had sucked what little juice I had as starting “freeboard” when I’d stopped and ran some lights and the max fan. On the new Highlander I made sure the tech wired the rig so that the battery was not giving up juice when the engine wasn’t running. I still unplug at the end of the day or on extended stops and check the lights before I get back on the road so I haven’t forgotten to plug back in. When traveling I only run the refrigerator on propane and haven’t ever tried it on DC.
Iowa Dave
Iowa Dave is offline   Reply With Quote
Old 01-24-2020, 08:31 AM   #9
Senior Member
 
Name: Steve
Trailer: Escape 15A
Minnesota
Posts: 452
Registry
Man, how much juice do those three-way fridges take??? My Engel fridge I use for overlanding only averages about 1 ah, depending on conditions, so it could go several days without running the battery down.
Steve Carlson is offline   Reply With Quote
Old 01-24-2020, 08:36 AM   #10
Senior Member
 
Alex Adams's Avatar
 
Name: Alexander
Trailer: 1979 Boler B1300
New Hampshire
Posts: 1,140
Quote:
Originally Posted by Steve Carlson View Post
Man, how much juice do those three-way fridges take??? My Engel fridge I use for overlanding only averages about 1 ah, depending on conditions, so it could go several days without running the battery down.
The standard RV fridge uses evaporation to cool down. To do this a heater is used either on AC or DC. When on DC, it uses a bunch of amps which is why you don't see any 12 volt heaters for RV's instead of propane. Your Engel fridge is a compressor type which uses compression and decompression to cool down. It uses a motor to drive the compressor and is therefore very efficient especially compared to the evaporation fridges.
Alex Adams is offline   Reply With Quote
Old 01-24-2020, 08:43 AM   #11
Senior Member
 
Joe MacDonald's Avatar
 
Trailer: 1981 Trillium 5500
Posts: 1,158
three way fridge in my trillium takes almost 30 amps DC to run it at 12 volts, uses nothing on Propane.
Remember on an absorption fridge, you are heating a chamber to recombine water and ammonia, not just circulating Freon with compressor.
absorption fridges are typically only 1/5th as efficient as a compressor fridge, but have the advantage of minimal or zero power draw
Joe MacDonald is offline   Reply With Quote
Old 01-24-2020, 08:59 AM   #12
Senior Member
 
Name: Steve
Trailer: Escape 15A
Minnesota
Posts: 452
Registry
Interesting, I always assumed they had a regular compressor for running on electrical. 30 amps, holy cow! I just looked it up and my Engel uses a maximum of 2.5 amps. Of course that Sawafuji swing compressor is really efficient and has little to no start-up surge draw.

My camper has a 120V dorm fridge. I haven't messed around with a 3-way fridge for a long time (decades). I just use the Engel when boondocking.
Steve Carlson is offline   Reply With Quote
Old 01-24-2020, 10:29 AM   #13
Senior Member
 
Perryb67's Avatar
 
Name: Perry
Trailer: 2016 Bigfoot 25RQ
Lanesboro, Minnesota, between Whalan and Fountain
Posts: 759
Quote:
Originally Posted by Lisle View Post
In this case, it's been cold here, I was running the electric fan on my propane heater, as well as the water pump and the frig on 12V. Cost me $1400 in repair bills and RV campsites while the car was in the shop. Sighhhhh.
Our Scamp 3-way absorption fridge took about two hours to kill the small 85ah battery. I never ran the fridge on 12v again. Other Scampers had similar experiences. Fast forward 10 years and now our Escape runs on 12v, but we have 220 ah of battery available. We accidently hit the 12v button on the fridge one day and a few hours later noticed our lights were dim. Took a while to find the culprit.

We NEVER run the fridge on 12v! I found out later that Escape could have put in a 2-way fridge at our request. I wish there was a way to install the 2-way board and panel, but alas, can't be done.

Think of how much gas you could have used for $1,400. Don't ever run your fridge on 12v!

Enjoy,

Perry
__________________
2016 Bigfoot 25RQ - 2019 Ford F-150, 3.5 V6 Ecoboost,

Previous Eggs -2018 Escape 5.0 TA, 2001 Scamp 16' Side Bath, 2007 Casita 17' Spirit basic, no bath, water or tanks, 2003 Bigfoot 25B25RQ, that we regreted selling
Perryb67 is offline   Reply With Quote
Old 01-24-2020, 10:47 AM   #14
Senior Member
 
Name: Justus
Trailer: Currently Shopping
California
Posts: 291
Quote:
Originally Posted by Raspy View Post
Lisle,

Everything fits together except why the car died while driving. Once running, the car battery should not go dead.

It is probably not a good idea to ever run the fridge on 12 volts. Not many vehicles send enough power through the seven pin plug to support that, and while plugged in, running it on shore power is better. While out camping, propane is best.
$1400 in repairs (even with several nights camping) indicates more than just new batteries. A problem between the alternator and battery could have resulted in the battery charging slowly or not charging at all, allowing the combined load of a running vehicle plus trailer, not to mention engine starts, to drain it.

I can confirm that our vehicle, a Toyota Highlander with tow package which includes a heavy duty alternator, sends enough juice through the 7-pin to power a 12v compressor fridge and charge the battery. I installed the 7-pin myself using 8-AWG wire. There is no relay to prevent charging while the engine is not running, and the aux charging is a straight shot from the 7-pin to the battery terminals (only breakers in between).

I quickly made a habit of unplugging as part of my post-parking walk around inspection for anything longer than a gas stop. Only downside is that I have to remember to plug it back in before hitting the road...
Justus C is offline   Reply With Quote
Old 01-24-2020, 10:57 AM   #15
Member
 
Name: Vicki
Trailer: 2019 Scamp 13' with 2015 Nissan Frontier V6
Alabama
Posts: 88
Thank you for starting this thread and for all the replies. I learned a lot reading this thread. I did not know about this and it has saved me from waking up to a dead battery!
Vicki Hale is offline   Reply With Quote
Old 01-24-2020, 11:28 AM   #16
Senior Member
 
Radar1's Avatar
 
Trailer: 2020 Escape 19 (was 2005 16 ft Scamp Side Dinette and 2005 Fleetwood (Coleman) Taos pop-up)
Posts: 1,227
Registry
I always unplug when stopped and I don't even have the 12 volt fridge option in our Scamp! Ours is 2 way; propane or AC.
__________________
Dave (and Marilyn who is now watching from above)
Sharpsburg, GA
04 Dodge Dakota V-8, 17 Dodge Durango V-6, 19 Ford Ranger 2.3 Ecoboost
radar1-scamping.blogspot.com
Radar1 is offline   Reply With Quote
Old 01-24-2020, 11:30 AM   #17
Senior Member
 
Perryb67's Avatar
 
Name: Perry
Trailer: 2016 Bigfoot 25RQ
Lanesboro, Minnesota, between Whalan and Fountain
Posts: 759
Quote:
Originally Posted by Justus C View Post
I can confirm that our vehicle, a Toyota Highlander with tow package which includes a heavy duty alternator, sends enough juice through the 7-pin to power a 12v compressor fridge and charge the battery.
She has an absorption fridge not a compressor fridge. Big difference!

Enjoy,

Perry
Perryb67 is offline   Reply With Quote
Old 01-24-2020, 11:31 AM   #18
Senior Member
 
Raspy's Avatar
 
Name: John
Trailer: Roamer 1
Smith Valley, Nevada
Posts: 2,880
My new HQ19 is wired a little differently than the typical American trailer. And it has already fooled me.

When disconnecting shore power, my fridge will default to 12volts. So I have to be careful to make it go to propane. The first time this happened it ran my batteries down to about 50% before I realized it. And this trailer does not charge from the seven pin umbilical.

Trailers are normally wired so that a small amount of current from the tow vehicle will charge the trailer battery slowly. The variables are that different amounts of power are available on different tow vehicles, some shut off automatically and some don't, and that some trailers are not wired to get that charge current to the trailer battery.

On mine, which is the Australian way of doing it, there is a separate high amperage plug that gets plugged in when the seven pin umbilical is plugged in. This second plug sends about 50 amps directly to the trailer battery. It is entirely separate from the umbilical system. It's called an Anderson plug, and I think it is the best way of charging the trailer from the tow vehicle. 50 amps seriously charges the battery and will carry the fridge load, if desired, while still charging the battery. Depending on how it is wired, it can be unplugged when parked for the night to disconnect the tow vehicle battery, or it can disconnect automatically when the engine is off.

With all of the unknowns, and all of the different methods vehicle manufacturers use, the Anderson plug is the best way to reliably get a lot of power to the trailer. It is a method specifically designed for that purpose. It is also a good way to charge the trailer battery while camped instead of running a generator. Just plug in and idle the truck for a while.
__________________
I only exaggerate enough to compensate for being taken with a grain of salt.
Raspy is offline   Reply With Quote
Old 01-24-2020, 12:02 PM   #19
Member
 
Name: Bill
Trailer: Scamp
CA
Posts: 66
Plug or unplug overnight

As everyone so far has advised, it's a good idea to unplug from the tow vehicle overnight. Or you can have a professional check your system. If it's determined you have no protection from battery drain from the tow vehicle's battery, and there's the possiblity you might forget to unplug, a battery isolator can be installed to prevent that. That could get expensive. I'd take the chance I would always remember.

Bill
Damp Scamp Tramp is offline   Reply With Quote
Old 01-24-2020, 01:30 PM   #20
Senior Member
 
Bruce H's Avatar
 
Trailer: Sold Bigfoot. Shopping for Arctic Fox 22G
Missouri
Posts: 701
Get one of these:


https://www.amazon.com/Midtronics-Di.../dp/B000RTAY5U


In in just a few minutes you can test the resting charge in your tow vehicle battery, the amount of charge it is receiving when the engine is running, the output your vehicle's alternator is putting out, the output from the individual terminals of your trailer plug, whether or not and/or how much current there is from your vehicle to your trailer with your vehicle not running, how much charge your RV battery is receiving from your tow vehicle when your tow vehicle is running, mow much charge your RV battery is getting from the converter when connected to shore power, how much current being drawn from your RV battery with various items in your RV being turned on or off, and a really important one: is current being drawn from your RV battery when it is disconnected from a charging source and every thing in the RV is shut off? The meter will measure down to 1/10th amp of DC current. Very few meters will do that.



I got one of these and In short (pun) I could easily solve the mysteries of voodoo vehicle electronics.


Here is one for $157.95:


https://www.jbtools.com/midtronics-a...SABEgIGxvD_BwE
Bruce H is offline   Reply With Quote
Reply


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
Rookie Hunter Compact Owner Esherman19 Problem Solving | Owners Helping Owners 49 05-13-2013 08:12 AM
Rookie questions Sean in VT Hi, I am.... 5 03-03-2013 10:32 PM
Torsion vs. Springs (through the eyes of a Rookie) daverosy Problem Solving | Owners Helping Owners 17 12-22-2012 09:13 PM
Rookie getting a new scamp camper Chita Hi, I am.... 2 10-29-2012 04:36 AM
rookie questions - Escape as tow vehicle, and Scamp v Casita Azer Problem Solving | Owners Helping Owners 30 06-16-2012 09:04 AM

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

Reviews provided by


All times are GMT -6. The time now is 02:05 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.