Tow Vehicle Battery and Alternator

[CJM1973]

My trucks alternator is rated at 150 amps. Its starting battery is your typical 600 CCA AC Delco variety.

My goal is to increase charging capability through the 7 pin pigtail connector near the hitch. Is this possible via a larger TV battery or alternator? I recently upgraded from 1 group 24 battery in the TT to 2 GC2 6 volts in series. Current setup doesn't provide much charging when underway, even after 5-6 hours of driving.

I know I can install a DC to DC charger in the trailer. I'd have to run a dedicated line from under the hood to the front passthrough storage compartment of the trailer. Just wondering if there was an easier route.

Don't want to invest in solar as I wont utilize it much. An 8 week to Alaska next summer is really what I'm planning for. Otherwise, we rarely boondock. It would be nice to drive for 4-5 hours and have a "topped-off" battery bank for each leg of the trip.

Any suggestions?

[Vintage465]

There is a blog called the "Adventurous Way". A young man named Matt Knight and his wife(Mrs. White?)are boon docking there way thu all the state parks. He has posted several "charging" upgrades he did on his rig. The last one I read was specific to this subject. He detailed it from start to finish. He got real successful results. Successful enough to cause me to consider.....but I have several other irons in the fire right now! And just for the record, I know nothing about blogs, I just stumbled upon it as someone posted a link to this episode of the blog on an Outdoor-RV forum or Outdoor-RV Facebook page.

[beck_vega]

You can try bamaboys towing.

[Rbertalotto]

LC Terminal = ????

We have no idea what this is for. Even Will Prowse couldn't understand the need. One of these days I'm going to call RENOGY to find out.

Will Prowse Video

There is a fuse with a plastic cover that I had in my junk box from back in the day when I installed high end car audio systems. I cut a hole in the plastic cover and mounted a simple SPST illuminated switch. This switch could be mounted anywhere.....

[CJM1973]

Rbertalotto wrote:
BTW...These photos do not show a quick disconnect on the 12v+ lead that is feeding the on/off switch. In this configuration, no wire is needed from the licence plate wire.

Thanks for posting the pics. Very helpful. What is the LC terminal for? So you wired in a fused switch between the (+) input and control terminal?

[Rbertalotto]

BTW...These photos do not show a quick disconnect on the 12v+ lead that is feeding the on/off switch. In this configuration, no wire is needed from the licence plate wire.

[Rbertalotto]

Actually, I use one Renogy DC to DC charger between the two vehicles. Using ANDERSON high current connectors, I can swap the unit back and forth.

I installed an ON / OFF switch right on the charger so I can shut it off when not needed. I run the DC control wire from my licence plate light wiring. In this way, when the lights are on, the DC to DC charger is on. And I don't need to run another wire from the front of the vehicle.









Battery Connection at tow vehicle

[CJM1973]

Rbertalotto wrote:
I have two tow vehicles, RAM 2500 with 220a alternator and Toyota Venza with 150a alternator. I use a Renogy 40a DC to DC charger in both for charging batteries in a small off-road tent camper or a large toy hauler. Both vehicles have 2g wire from front battery to charger in rear.
The Renogy works way above my expectations. Amazing product.
I've been experimenting using my vehicle to idle and charge the battery. After 20 minutes charging I'm seeing very little heat rise on either alternator.using laser thermometer. And with a AGM group 31, 100ah, 60% battery, I'm back up to 90% after 20 minutes.
I no longer carry a bulky generator to off grid charge batteries when the sun isn't hitting my solar panels.
Do a Search on YouTube for Will Prowse. He is amazing and has done a great test on this Renogy unit.

Thanks for the late input. Good to hear that it's been working great for you. I have yet to install the Renogy DC to DC charger in my tow vehicle as we are still in the middle of winter in Michigan. How did you wire the control terminal on the unit? Did you use your tow vehicle's ignition circuit? I have 4G wire (both pos & neg) to run from the TV's battery to the input on the Renogy unit. I'm wondering if I can just tap into the trailer's tail lights or do I need to run a dedicated 16-18G wire from the vehicle's ignition wire. House Batteries and Renogy are installed in a tongue box on the travel trailer. I would prefer only to have one 2-pin connector from TV to trailer. Just curious to how yours is wired.

[Rbertalotto]

I have two tow vehicles, RAM 2500 with 220a alternator and Toyota Venza with 150a alternator. I use a Renogy 40a DC to DC charger in both for charging batteries in a small off-road tent camper or a large toy hauler. Both vehicles have 2g wire from front battery to charger in rear.
The Renogy works way above my expectations. Amazing product.
I've been experimenting using my vehicle to idle and charge the battery. After 20 minutes charging I'm seeing very little heat rise on either alternator.using laser thermometer. And with a AGM group 31, 100ah, 60% battery, I'm back up to 90% after 20 minutes.
I no longer carry a bulky generator to off grid charge batteries when the sun isn't hitting my solar panels.
Do a Search on YouTube for Will Prowse. He is amazing and has done a great test on this Renogy unit.

[time2roll]

CJM1973 wrote:
One last question regarding my new AGM battery bank. What are the ideal charging parameters to set my AC to DC converter at? Bulk, absorption, and float.

The battery manufacturer will be the best resource on charging specifications.

[BFL13]

Undercharging, not overcharging will be the issue. You need an ammeter to tell when amps are down to 0.5/100AH. That does not mean 1.5a for the bank of three, since the middle battery will not get its full share. I use my Trimetric as the ammeter. You need to do each battery separately to true full as often as possible.

On a trip it is too difficult to do all this right, so it is what it is. At home, you can do it right. See the AGM charging guide here, scroll down

https://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf

[CJM1973]

One last question regarding my new AGM battery bank. What are the ideal charging parameters to set my AC to DC converter at? Bulk, absorption, and float. I think temperature has a play in the equation. Considering the money spent on these AGM batteries, I would like to have them around for awhile and avoid any overcharging scenario. We usually camp in fair weather temps (60-80*F). From my understanding, our trip to Alaska will have such a broad range of temps. I'm coming out of flooded GC2 batteries.

[time2roll]

Rbertalotto wrote:
Well...Learn something new every day.....Looking at Renogy Install Manual

"When selecting a location for the DCDC, make sure that the unit is as close as possible to the battery you will be charging (auxiliary battery). "

I had read on a few other sites to put it close to the main battery.....Don't trust everything you read on the internet.. 🙂

All charging systems work better when close to the battery getting charged.
Solar, converter, alternator, and this Renogy dc/dc charger.

[Rbertalotto]

I ordered the Renogy 40A version to charge my portable battery box I just built for my Roof Top Tent....and to charge the trailer batteries when I'm pulling that unit.

These DC to DC chargers are really neat...Lots more control and safety for your alternator and your batteries that a simple solenoid like we used to do.

With my 2018 RAM I understand that a simple solenoid setup will confuse the computer controlled alternator but these DC to DC chargers are fine....

We shall see!

You can see my Portable Battery and RTT solar here:

www.rvbprecision.com

[CJM1973]

Rbertalotto wrote:
Well...Learn something new every day.....Looking at Renogy Install Manual

"When selecting a location for the DCDC, make sure that the unit is as close as possible to the battery you will be charging (auxiliary battery). "

I had read on a few other sites to put it close to the main battery.....Don't trust everything you read on the internet.. 🙂

Yeah, I learned early on that there are a bunch of liars on it...except for maybe RV .net. 😉

I bought a water proof tongue box that I will install it in along with my 3 AGM 100 AH batteries. Between the new battery bank and this new DCDC charger, I our Alaska trip will be less reliant on firing up the old inverter generator. I'm bringing one just to be safe.