Question for the electrical experts here

[ClassicTractorProfessor 5,314]

As most of you already know my main reason for purchasing the new truck was to haul my camper in. I have an idea of something I want to do, but my brain is not letting me come up with a solution. I'm probably overthinking a simple setup, but here goes. 

 

On my F150 whenever I loaded the camper I just set the battery inside the bed directly in front of the left wheel well and hooked the wiring directly to it. Since this new truck is going to be the dedicated camp rig I would like to do something a bit more permanent. What I'm wanting to do is install my camper battery under the hood in the auxiliary battery box and run my electric back to a plug in the bed. This will allow me to just plug the camper in when I load it and simply unplug it when not needed, as well as have the marker lights on the camper working with the switch for the marker lights on the truck. That part I have figured out without any problems. 

 

Where it gets tricky for me is I want to have the auxiliary battery connected where it will charge off the alternator when driving down the road, but I want it isolated from the truck battery so as not to run the risk of draining it and leaving us stranded somewhere. What is the simplest and most cost effective way to do this. I know it can be done as my 1991 Tioga RV is wired that way, but space is so limited under the hood I really can't see how they have everything hooked up

[Pullstart 62,795]

Bryce,  if you were to wire the auxiliary battery via a solenoid, you could have your signal wire come on with your truck ignition.  Would that do what you need it to do?

[gwest_ca-(File Mod) 11,033]

Click on these for a description

https://www.princessauto.com/en/search?Dy=1&Nty=1&Ntt=Battery+Isolator

 

Garry

[troutbum70 857]

Bryce you can very well use a isolator, or you can run a heavy wire from your alternator into your cab to a 30 amp toggle switch. Then run a heavy wire from the switch to your battery, while driving leave switch on to charge battery, when not running the engine flip switch off so as to not discharge your truck battery. I know some may no, but I  ran a huge auxillary  battery on my semi for many years and that is how I maintained it.

[Achto 27,505]

Probably the cheapest method would be to install a knife switch on your camper battery. Open the switch when you park the camper to disconnect it from the truck battery. After you start the truck close the switch so that it will charge off of the truck. Not the handiest but cheapest.

 

https://www.ebay.com/p/3026066854?iid=223236833822&chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=223236833822&targetid=539174542515&device=c&mktype=pla&googleloc=9019452&poi=&campaignid=6470552772&mkgroupid=81274341727&rlsatarget=aud-298628318826:pla-539174542515&abcId=1139336&merchantid=113790136&gclid=CjwKCAiA6bvwBRBbEiwAUER6JX6nLe77MpqzzbAYMsPMYTtMc-vLIGv5Nl0uZRJPCw1vzfIJZFOpiBoC68oQAvD_BwE  

Edited January 4, 2020 by Achto

[Tractorhead 9,064]

Had 2 suggestions, depending on your charging consumpts needed.

but for closer infos, 

what kind of Battery in Trailer in Ah and what load they shall support for how long?

older Truck ( before 2006 or later) 

 

are both batteries same type? Lead acid or did they differ?

lead acid has other charging curve than Gel i.eg.

 

@troutbum63 if you do so, please dont forget a second fuse on the receiverbattery also.

even if switch was in off position, the wire holds the Power from trailerbattery until Switch.

 

Low power Charging

firstly if you had a 13 pin Trailerconnector, you can use this for quick connecting disconnecting the whole Trailer.

like Pullstart suggesting.

On the 13 pin trailerconnector there are 2 pins for Power reserved and 2 Pins for Ground.

 

 

As long as your Charging Current didn‘t exceed 40Amps ( means a battery with less than 120Ah) use a simple Solenoid in the Truck.

 

Connect Ignition line with a 3A Fuse to one side of the Solenoid coilpin the other coilpin directly to ground.

one Direct line from Truck battery with a 50A Fuse directly to the solenoid switch, wiregauge at least 6 square mm - better 10 square.

the other side of Solenoid switch with 2 Wires with each at least 2,5square mm to you Trailerconnector.

The Ground side also with 2 wire in same diameter to chassis Ground.

That will be save for up to 40A Charge continousely.

 

Don‘t forget to put also a second fuse onto Trailerbatt in the Charging line, to save the Wires.

 

Function:

if you switch the Key, the Truck will switch the solenoid and the Camper was feeded with charging Power.

as long as you don‘t start, both battery’s will be just connected.

if you start the engine both batteries will be charged.

 

 

a more safer and better Version to charge your Trailerbattery was,

to use a charging converter ( sometimes b2b charger or charging booster called)

Additionally some Charging controller reduces the Voltage automatically an needs a Chargingconverter to work correctly.

( that was my reason i‘m asking for the year of build)

This B2b charger support you with a regulated Current by max. 25-30A because most Trailerconnector Pins are rated at 20A each in and max. 25A each

This can also be simply attached via Ignition line or via D+ ( i guess in us Cars it’s called Line L)

 

i.eg. Like this

https://www.votronic.de/index.php/en/products2/series-vcc/standard-version/vcc-1212-30-new

 

The biggest Advantage here is you have a charging program for several different Battery types.

and if connectet via L line, the charging converter just starts if Engine is running and battery is charging.

There is a short delay at about 10-30 sec. The system waits Before start Charging.

This prevents definitively your truckbattery goes empty by charging, even Engine ain‘t runs and ignition is on.

 

 

 

2. version Higher Power Charging

 

if you like to use 2 or more stronger battery‘s i would suggest,

using instead a Trailerconnector for charging a separate Connector like the AMP Types,

same as they would be used by electric forklifts. They will be available up to 300Amps.

 

because i don‘t know your exact need, my sugges was that widely spreaded.

If i get more infor, i can give you the best suggest.

 

regard Steve

Edited January 4, 2020 by Tractorhead

[ZXT 2,401]

4 hours ago, pullstart said:

Bryce,  if you were to wire the auxiliary battery via a solenoid, you could have your signal wire come on with your truck ignition.  Would that do what you need it to do?

I wonder if a typical 40a 4 pin relay would do the job? I figure it would work fine as far as charging. I know it couldn't handle trying to crank off of the battery (as it would if it were directly connected), but that's not an issue since the relay would kick out when the key was put into the start position. 

 

If nothing else, you could go low-tech and put a simple battery cutoff switch that would separate the two batteries when shut off. I know HF has them on their shelves for something like $7 a piece. Probably not the heaviest duty switch out there, but you aren't going to be pulling much through it.

[Pullstart 62,795]

Just a thought Bryce.  My camper has a battery bank, charging through the 7 pin wiring harness.  It was one deep cycle battery, I added a second to double my amps for one long weekend a year that we live in a field near Kyle Lingerich at some cool races.  When the camper is plugged into the truck, it’s a direct connect to the batteries in the truck (fused).  When the camper is plugged into 110 volts, it automatically is charging the 12v system too.  Is your truck camper the same, with a 110 volt AC plug and a 12 volt DC source too?  If that’s the case, adding extra pins to the circuit like @Tractorhead mentioned could automatically aid in triggering a charge solenoid to link the truck and the camper.  Otherwise, I’ve never had an issue with the camper drawing the truck to the point of not starting.

[Tractorhead 9,064]

7 hours ago, ZXT said:

I wonder if a typical 40a 4 pin relay would do the job? I figure it would work fine as far as charging.

 

 

As lon* as your Battery is in good condition and not too big, it will work.

If battery gets older it needs a longer charging cycle, depending on last of the Battery.

The relais points internally are also bit different depening on brand and Manufacturer.

if Batterycharging current will be longer time above the rated relaycurrent, it will die so or so.

mostly they stick in connected state silently,  smell or smoke ain‘t be each time a following process of it.

 

i would suggested at least a 70A charging relay, to have more spare

and adequate AWG in wire to reduce the currentdrop by resistance on this length of charging wires.

 

Never miss at least 2 Fuses, on each edge close to Battery one fuse they protect the battery‘s and wire in case of a short.

[Tractorhead 9,064]

6 hours ago, pullstart said:

  When the camper is plugged into 110 volts, it automatically is charging the 12v system too.  Is your truck camper the same, with a 110 volt AC plug and a 12 volt DC source too?  If that’s the case, adding extra pins to the circuit like @Tractorhead mentioned could automatically aid in triggering a charge solenoid to link the truck and the camper.  Otherwise, I’ve never had an issue with the camper drawing the truck to the point of not starting.

 

Good point Kevin,

i ain‘t seperate mention that, because i made this in our RV Installations as a basic Standard.

 

another good thing will still be an added Solar charging.

one House- cell, they here typically rated with 170W will support you in summer with electrical Energy.

on Solar not the max on Watt‘s allone was counting, it was a balance of Wattage and Time, how long charging works.

For a solar Cell you have to use a regulator for, but here we can also charge both battery‘s at once.

 

You can calculate for a Housecell (170W Cell) 170W/12V = 14A at full Load. 

Realistic it will bring nearly full Load at about 12-13A, few Cell i seen with more (up to 15,4A)

But ain‘t use Camping Cells, because they rated on 17- 28Volts at idle Voltage Peak,

so the brightness to begin charge must be hardly more than on House Cells rated idle Voltage is 54-56V.

Here charging begins earlier and ends up later, even cells itself are much cheaper.

 

few examples, ain‘t just calculated, they self experienced knowledge over 25Years.

 

so at middle sunhours in winter on about 4h with non ideal charging,

you will take about at least 18 AH on additional Charge a day.

but solar cell must be cleaned.

 

in Summer it will raise in non ideal charging it will feed you between 54 and 56 Ah a day.

 

This we can discuss this more closer on June at the Big Show.

 

 

 

[Pullstart 62,795]

Bryce, this is what Stefan does day in day out.  His work is masterpiece quality.  If I break down his points, chew on them for a bit then move on, I usually learn (read soak in) a tiny bit more each time.

[Tractorhead 9,064]

Thanks for the Flowers Kevin..😎

 

ok, to show you what i meant with Solar,i was short in my Barn, to give you an idea about Solarcharging in Winter.

 

firstly, i have absolutely no Sun here it is 15:45 at Cloudy Heaven.

 

 

 

My Solarpanel is a Housepanel with 250W in Peak, my Battery was a Gel Type with 120Ah.

i had an Inverter continousely running in Standby with a drop of 1A about. And few Lights with motiondetector.

 

i just do a few Voltage measuring, because the Charge depending on time.

 

firstly the Battery Voltage measured on the Solar Regulator

 

as you can see, the Battery is fully Charged in idle

with and the second Charging for startbattery i using outside, to keep Motocycle batt in working condition.

that‘s a very handy installation. This second charging output you can use for the Truck Battery.

 

now we have a closer look at the Cell Voltage

 

 

and as you can see, even in weak light, i got more as needed to charge a Battery.

that means in fact, the Solarcharger handles the drop of the Inverter, and the balance is even now still in positive.

 

this System runs now for 10years in that combination, still with all components.

No batterychange until now. 

I just moved the whole system with all components about 5years ago from my RV to the Shed,

because i sold my RV.

 

 

 

 

 

[ClassicTractorProfessor 5,314]

Thank you everyone for the suggestions, i figured I was making something relatively simple way too complex. I will probably try to get something rigged up in the next week or so and post what I do...loaded the camper this morning so I have a place to stay while in Texas working on our new house this weekend, just hooked it up the way I had it in the Ford for now. 

 

On a side note it is so much nicer having a truck that the camper actually fits in the way it was designed to

[ZXT 2,401]

3 hours ago, Professor1990 said:

Texas working on our new house this weekend, just hooked it up the way I had it in the Ford for now. 

 

 

 

In what part of Texas are you going to wind up?

Edited January 5, 2020 by ZXT

[adsm08 2,022]

On 1/3/2020 at 8:33 PM, troutbum63 said:

Bryce you can very well use a isolator, or you can run a heavy wire from your alternator into your cab to a 30 amp toggle switch. Then run a heavy wire from the switch to your battery, while driving leave switch on to charge battery, when not running the engine flip switch off so as to not discharge your truck battery. I know some may no, but I  ran a huge auxillary  battery on my semi for many years and that is how I maintained it.

 

This is a bad idea.

 

Without an isolator if the batteries are mismatched in health, age, or amp rating this can cause one to under charge and the other to over charge, possibly ruining both, as the alternator tries to hit the average. Usually it overcharges and damages the newer of the two as it tries to bring the older one up to that level.

 

It is much better to run an isolator that will shut the charge to the auxiliary battery off when it hits full charge.

[ClassicTractorProfessor 5,314]

45 minutes ago, ZXT said:

In what part of Texas are you going to wind up?

Canadian, up here in the panhandle, it's only about 45 miles from where we were living in Oklahoma...close enough I can keep my job at the shop 

[ZXT 2,401]

3 minutes ago, Professor1990 said:

Canadian, up here in the panhandle, it's only about 45 miles from where we were living in Oklahoma...close enough I can keep my job at the shop 

Never knew that we had a town named Canadian! I know Oklahoma has a stupid personal income tax, whereas Texas doesn't. If you live here and work there do you not have to pay it?

 

Welcome to Texas! 

Edited January 5, 2020 by ZXT

[ClassicTractorProfessor 5,314]

With me driving back and forth every day, as well as driving the wrecker during the week, I'm keeping my address at my shop up there and keeping my Oklahoma tags and license, but if I permanent transferred everything down here I don't know if I would still have to pay it or not

[Pullstart 62,795]

@ZXT I think TN is the same, with no personal income tax.  Wow, to think a man could work and get the money he earned.  It would be interesting to see how that played out with a permanent residence in one state but a job in another.

[wallfish 16,985]

7 hours ago, pullstart said:

Wow, to think a man could work and get the money he earned.  It would be interesting to see how that played out with a permanent residence in one state but a job in another.

No state income tax in the state of NH so many people live there but work in Boston. The trade off is the horrible traffic because so many do it. Maybe add 1.5 hours of EXTRA travel time each way because the traffic is so bad in and out during rush hours. That's an extra 3 hours a day or 15 hours a week.