Jump to content

Dual battery setup

Gr8FrozenNorth
 Share

Recommended Posts

Another JR Senior Enthusiast

Another JR

Posted
Posted (edited)

Keep in mind that a side effect of connecting any load to the trailer marker light circuit is that the truck detects a trailer. That causes the rear parking assist to be turned off. This will happen even if you simply have a connector with an LED circuit check light on the connector.  A slide in camper sized for a full size truck is typically wide enough that the DOT marker light requirement applies, so it will have marker lights you’ll want to wire to the truck marker light circuit. I would recommend separately wiring your camper to the appropriate truck battery and truck marker light circuit rather than using the trailer circuits to avoid defeat of safety features you may want active. 
 

Also, taking off the tailgate will disable the entire camera system unless you wire in a replacement camera. 
 

Will your camper have its own battery?

 

I installed a Four Wheel Campers Grandby pop-up slide in on my truck with a 200 Ah lithium battery, solar, and a dc to dc charger for charging from the truck. I installed a camera on the back of the camper to replace the tailgate camera. I’m happy to answer any questions about how I set mine up and why. 

Edited by Another JR
  • Replies 35
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Popular Posts

mkeddie
mkeddie

I paid the small amount to have the dual battery installed at factory it's alot easier that way lol     Sent from my Moto Z (2) using Tapatalk        

mkeddie
mkeddie

Stay tuned and u will see all my fun Sent from my Moto Z (2) using Tapatalk

redwngr
redwngr

And now the factory dual alternators are a 220 with a 170    KHF         Alternators, dual, 220-amps primary, 170-amps auxiliary 1 - With (L8T) 6.6L V8 gas engine, (K4B) 730 cold-cranki

Posted Images

03 Cobra Enthusiast

03 Cobra

Posted
Posted
On 9/1/2021 at 1:26 PM, Another JR said:

Keep in mind that a side effect of connecting any load to the trailer marker light circuit is that the truck detects a trailer. That causes the rear parking assist to be turned off. This will happen even if you simply have a connector with an LED circuit check light on the connector.  A slide in camper sized for a full size truck is typically wide enough that the DOT marker light requirement applies, so it will have marker lights you’ll want to wire to the truck marker light circuit. I would recommend separately wiring your camper to the appropriate truck battery and truck marker light circuit rather than using the trailer circuits to avoid defeat of safety features you may want active. 
 

Also, taking off the tailgate will disable the entire camera system unless you wire in a replacement camera. 
 

Will your camper have its own battery?

 

I installed a Four Wheel Campers Grandby pop-up slide in on my truck with a 200 Ah lithium battery, solar, and a dc to dc charger for charging from the truck. I installed a camera on the back of the camper to replace the tailgate camera. I’m happy to answer any questions about how I set mine up and why. 

 

I am interested to know how you tied in the DC-DC charger for your lithium battery.  Did you integrate it into the factory isolator on your aux battery?  Or wire it direct to the alternator?  I was toying with the idea of replacing my aux battery with a lithium and hooking a DC-DC charger up to the wiring that's already there for the aux set up.  First I would check the under hood temp as they don't like to live above 135*F.  If it passes the temp test that's what I thought to do for camping in the back of my truck under my camper shell.  Then I would use the 7 pin plug that's already in the bed that came with the 5th wheel package.  There's probably a smarter way but that's what I came up with.  Thoughts?!

Another JR Senior Enthusiast

Another JR

Posted
Posted

The dc to dc charger for camper battery charging normally is only intended to charge the camper battery when the engine is running, and will have some means to detect engine running. Because it only draws current when the engine is running there is no need to further isolate it from the main battery to prevent discharge. 
 

I connected 6awg wire to the main truck battery fuse block unused 80 amp fuse for the positive, and to one if the large body ground studs for the negative. I actually used the ground stud the aux battery negative is connected to because it was most accessible, but it doesn’t matter which one you use as long as it’s good for the total current. The dc to dc charger is located next to the camper battery in the camper. 
 

I wouldn’t think that the environment under the hood is acceptable for a lithium battery, especially on hot days. Also, dc to dc chargers generate quite a bit of heat and at least the 30 and 50 amp ones are typically passively cooled with fins, and they need cooler environmental conditions to stay within acceptable operating temperatures to avoid output cutback or failure.  There would be concerns with subfreezing conditions as well. 

 

I ordered my second battery for truck mounted accessories like a compressor and in-cab portable refrigerator, not for supporting a camper electrical system. I briefly considered a lithium battery and dc to dc charger setup under the hood for these accessories, but ruled it out because of the temperature issue.  The second battery option was so cheap I just went with it and expect it will be fine for my planned accessory use. 
 

For camping in a shell I’d probably use an easily removeable battery installation inside the shell. If you already have the fifth wheel connector you can use the power from that as you said to run a small dc to dc charger that is at your camper battery.  

03 Cobra Enthusiast

03 Cobra

Posted
Posted
On 9/3/2021 at 11:54 AM, Another JR said:

The dc to dc charger for camper battery charging normally is only intended to charge the camper battery when the engine is running, and will have some means to detect engine running. Because it only draws current when the engine is running there is no need to further isolate it from the main battery to prevent discharge. 
 

I connected 6awg wire to the main truck battery fuse block unused 80 amp fuse for the positive, and to one if the large body ground studs for the negative. I actually used the ground stud the aux battery negative is connected to because it was most accessible, but it doesn’t matter which one you use as long as it’s good for the total current. The dc to dc charger is located next to the camper battery in the camper. 
 

I wouldn’t think that the environment under the hood is acceptable for a lithium battery, especially on hot days. Also, dc to dc chargers generate quite a bit of heat and at least the 30 and 50 amp ones are typically passively cooled with fins, and they need cooler environmental conditions to stay within acceptable operating temperatures to avoid output cutback or failure.  There would be concerns with subfreezing conditions as well. 

 

I ordered my second battery for truck mounted accessories like a compressor and in-cab portable refrigerator, not for supporting a camper electrical system. I briefly considered a lithium battery and dc to dc charger setup under the hood for these accessories, but ruled it out because of the temperature issue.  The second battery option was so cheap I just went with it and expect it will be fine for my planned accessory use. 
 

For camping in a shell I’d probably use an easily removeable battery installation inside the shell. If you already have the fifth wheel connector you can use the power from that as you said to run a small dc to dc charger that is at your camper battery.  

 

JR, your points resonate with what was already in the back of my head....the lithium battery and dc to dc charger will not live as long under the hood.  I think you helped convince me to tuck them away in the bed somewhere instead.  I hadn't thought of using the 7 pin that's in the bed to run the dc to dc charger.  Do you think the wiring for the 7 pin will be heavy enough to run the dc to dc?  I might just run a new positive and negative wire up to the engine bay and hook mine up similar to what you did.  Then, if I am not putting the lithium battery under the hood I wonder it if would be worth it to replace the factory aux battery with a good AGM battery.  Just to get more out of it and avoid the scenario where I discharge the factory aux battery too far (I think 50% is the accepted limit) and cut it's life short.  Anyway...fun stuff to think about.

Another JR Senior Enthusiast

Another JR

Posted
Posted

You can use pin 4 of the trailer connector, which comes from the aux battery fuse block, as long as you ensure your dc to dc charger engine running detection logic is set properly to shut off the charger when the engine is shut down. You don’t want to discharge the aux battery with the dc to dc charger. Also, that wire is protected by a 30 amp fuse. A 20 amp dc to dc charger should work fine. A 30 amp one probably would blow the fuse.  If you do it this way, use the trailer connector ground wire - don’t use the truck body as the current return. 
 

If I was doing lights, electronics charging, and a fridge in a canopy without solar, I’d get a 70 to 100 amp hour battery and a 30 amp charger, and run new 8 awg positive and negative wires to the main battery fuse block and a large engine compartment ground stud.  That way you’d have at least two days of energy storage and you could recharge a nearly discharged battery in two to three hours of driving.  

 

03 Cobra Enthusiast

03 Cobra

Posted
Posted
17 hours ago, Another JR said:

You can use pin 4 of the trailer connector, which comes from the aux battery fuse block, as long as you ensure your dc to dc charger engine running detection logic is set properly to shut off the charger when the engine is shut down. You don’t want to discharge the aux battery with the dc to dc charger. Also, that wire is protected by a 30 amp fuse. A 20 amp dc to dc charger should work fine. A 30 amp one probably would blow the fuse.  If you do it this way, use the trailer connector ground wire - don’t use the truck body as the current return. 
 

If I was doing lights, electronics charging, and a fridge in a canopy without solar, I’d get a 70 to 100 amp hour battery and a 30 amp charger, and run new 8 awg positive and negative wires to the main battery fuse block and a large engine compartment ground stud.  That way you’d have at least two days of energy storage and you could recharge a nearly discharged battery in two to three hours of driving.  

 

 

I think my plan is starting to come together.  Everything will be in the truck bed except for the wires that run up to the engine bay. I'm looking at a Redarc BCDC 25amp charger so I can handle solar and have ultimate flexibility with the type of battery.  As for the batteries I will go with 2-100 Ah Battle Born lithium batteries that both have the heating element to  keep them warm in the frigid Michigan temps.  I need to do more research on the pure sine inverter I want to get.  Fun, and expensive, stuff!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Grumpy Bear
      Some Assembly is Required

      By Grumpy Bear · Posted

      Can it still be Assembled I?    Stribeck says that we need a certain amount of viscosity under conditions of load and velocity to prevent two surfaces of a know roughness from tearing each other asunder. And we have marketing trying to tell the masses that those two surfaced require less of that commodity due to more exact limits being placed on the same old clearances. We also know that there are limits to how hard something can before it becomes to brittle to be viable and to smooth to 'wet' the surface and that both of those conditions have been known and met since about the Second World War.    That viscosity value shook out at 10 centistokes at 212 F just under a hundred years ago.  Give this a look: [Anton Parr]     What is advertised is the Kinematic viscosity (mm2/s) or that which has been density adjusted but the value we are after is the dynamic viscosity (mPa.s) or true viscosity. You can see that this number is dependent on density thus base stock and temperature. You can also see that an SAE 30 doesn't reach that value in this example. However an SAE 30 that is at the upper end of the SAE 30 range; 12.5 cSt (mm2/s), might. 12.5 * .83 = 10.375 (mm2/s). If you could find an SAE 30 at the upper end these days.   Then there is the complication of viscosity modifiers or VII or VM, whatever you wish to call them. Polymers added to very thin base oils, perhaps 3 to 6 cP oils, that will meet the SAE *W30 spec at 'tested' shear rates and 100 C/212F  target temperature. So a polymer fortified base that is a fraction of the 10 cP requirement Stribeck insist upon.   This could be all well and good if those polymers didn't have two very problematic 'features'. They shear or loose viscosity both 1.) permanently and 2.) temporality. And they do both omitted in the advertised data with the distinct  purpose of deceiving the consumer of the actual operating state of the fluid. I've shown the example of Warren Oils COSTCO 10.91 cSt 5W30 formuation several times where the 100 C HTHS value is 6.9 cP!! That's the temporary shear down and with and SSI or shear stability index of 9.4 cSt. Note the intentional deception in using mixed units?    After a short while that 9.4 cSt oil has a viscosity corrected dynamic value of 7.8 cP. But as the SSI is still within the range of an SAE *W30 whose lower value is 9.3 cSt.    This allows them to continue to call this SAE 16 weight oil a 30 weight, the cake, and still meet the API requirements for fuel efficiency IMPROVEMENT mandated by the EPA. The eating of the cake. By the time you've worn out your motor doing the responsible thing by adhering to the warranty requirements, (the stick), you get deprived of the carrot, wear control. So sad, to bad.   So what can be done? Do I need actually say? [Anton Parr]       Even this must be monitored if the oil is on the low side and the VII an organic or you opt for a 0W40 with an even lighter base oil and more / higher MW VII. (Note the lower density of the 40 weight versus the SAE 30 mono-weight?)    There is another workaround. Temperature. An SAE *W30 run at a bulk temperature of between 180 and 195 F.    Being the belt and suspenders sort I am I do both. Run it cook and run it heavy.    In Part II I'll work the AW package. 
    • Atlas
      Wow I'm in a pickle. (Broke down truck) and a story.

      By Atlas · Posted

      So, do I go elbow-deep on this thing or list it for sale and play dumb? Seems to "runs good."   I'm about $1200 away from having: -a rebuilt injector ($300) -a new cat ($250) -a new cat back exhaust (OE style) ($300) -a new AC compressor ($200) -AC refrigerant charge ($150)   In theory, this should rectify the obvious detracting issues from its value and operability. Cold AC with a non-squeaking AC pulley both sounds and feels good. An exhaust that isn't cut/hacked in 17 different places and doesn't vibrate on a crossmember would make it sound and feel less janky. A working cat would help the stink, and will save the earth, but *if and only if* the fuel system is working properly, which would also address the intermittent "rich" CEL.   Heard a good one... CEL for "Rich condition" means you haven't spent enough money on the truck lately, and it's letting you know.   Rebuilding the injector would seem to be the most important part. Replacing the cat would be secondary. I don't think mine is plugged or overly restricted, but it might be a little restricted? I have no good way to tell other than seat of the pants feel. I hate the smell.   The current theory is I have a rich idle problem: A bad fuel pressure regulator, or a leaking injector(s) being the highest probabilities. I already replaced the FPR but that doesn't mean its replacement isn't also bad. It was a new part from Dorman, but the packaging looked like it had been sitting on a shelf for 20 years.   This is the (single) upstream O2 sensor shown at idle. I'm getting a lot of "rich" it seems. Sometimes it stays high like that and doesn't drop down. That makes me think it's processing injector leaks or a partially stuck open injector.     Other times it looks like this. Nice oscillations between rich and lean, which is what I think it should be. Under load and at speed, the oscillations are nice and tight and uniform looking, high and low.     Fuel trims suggest the PCM is compensating pretty hard at idle to pull fuel out. But it's not enough to trip a CEL. Something about slowing to a stop: brake vaccum booster, EGR, or the EVAP purge is delayed, or there's pooled fuel in the intake again that's draining into a cylinder is enough to set the CEL. Of course, in two days of driving, it hasn't set. I was hoping to actually look at the freeze-frame data when it sets. IAT is high because it's idling on an 83 degree day here.  
    • Another JR
      Gasser Subforum Has Been Quiet - - So, Regenerative Braking and Using L10

      By Another JR · Posted

      Have considered installing a DC to DC charger in your camper to replace your isolator?  
    • newdude
      Gas fill door

      By newdude · Posted

      Common failure.  You need to replace the fuel door housing.   The painted cover transfers over to the new housing.  To remove the old one there is 4 spots where you poke the plastic to release it.  
    • newdude
      Gasser Subforum Has Been Quiet - - So, Regenerative Braking and Using L10

      By newdude · Posted

      No such thing as regenerative braking on a pure ICE vehicle.     Regenerative braking is the re-capture of energy from electric motors and stores it in the battery pack.  So hybrids, PHEV and EVs have regenerative braking.     What you are seeing is the charging system changing modes is all.  Its likely entering charge mode for some sort of reason is all.  All of the charging modes will be listed below.   As for L10 vs D.  L10 turns off automatic grade braking.  L10 puts you in control of grade downshifts where in D it will automatically do it based on brake pedal position and other factors.  Otherwise L10 and D drive exactly the same aside from that one aspect.    Battery Sulfation Mode The BCM will enter this mode when the interpreted Generator output voltage is less than 13.2 V for 45 minutes. When this condition exists the BCM will enter Charge Mode for 2–3 minutes. The BCM will then determine which mode to enter depending on voltage requirements.   Charge Mode The BCM will enter Charge Mode when ever one of the following conditions are met:   Windshield wipers are ON for more than 3 s. Climate Control Voltage Boost Mode Request is true, as sensed by the HVAC control module via serial data. High speed cooling fan, rear defogger, and HVAC high speed blower operation can cause the BCM to enter the Charge Mode. The estimated battery temperature is less than 0°C (32°F). Battery State of Charge is less than 80%. Vehicle speed is greater than 145 km/h (90 mph) A current sensor malfunction exists. System voltage is determined to be below 12.56 V When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9–15.5 V, depending on the battery state of charge and estimated battery temperature.   Fuel Economy Mode The BCM will enter Fuel Economy Mode when the estimated battery temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 A and greater than −8 A, and the battery state-of-charge is greater than or equal to 80%. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5–13.1 V. When fuel economy mode is active, the generator is not charging, only maintaining open circuit battery voltage. The BCM will exit this mode and enter Charge Mode when any of the conditions described above are present.   Headlamp Mode The BCM will enter Headlamp Mode when ever the head lamps are ON (high or low beams). Voltage will be regulated between 13.9–14.5 V.   Start Up Mode When the engine is started the BCM sets a targeted generator output voltage of 14.5 V for 30 s.   Tow/Haul Mode (if applicable) Pressing the Tow/Haul Mode button located on the center stack, the vehicle system voltage is raised and the remote (non-vehicle) battery will be charged. Having the headlamps on will raise the system voltage and if the Tow/Haul button is applied it will not serve any purpose. The voltage is regulated between 13.9-14.5 V.      

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...