Startling behavior of a RAM 1500 HEMI 5.7 with e-Torque - TV parasitic draw from RV

[Overland]

21 hours ago, GraniteStaters said:

Overland, we are easily able to charge our AGM batteries using the generator on the Ram with e-torque.  We are also able to power the the refrigerator on DC when we travel between campsites without any issues.  The rating for the generator is quite high.  This isn't your father's alternator.

Trucks are definitely changing, especially with the shift to hybrid charging, so I won't deny that you're getting a charge, but I do have questions.  First, I'm curious how many amps of charge you're seeing and how that changes over time vs just at startup when the alternator is charging the start battery.

My alternator will give 14.6 volts for a bit, but only until it senses that the starting battery is recharged, then it drops into, if I remember right, the low 13's, which isn't enough to charge lithiums even without taking into consideration the .3 to .5 drop in voltage that you'd see over the distance to the batteries.  This happens even with a house battery in the truck, connected with 2 awg cables.  That behavior seems pretty common for modern truck electrical systems, but of course with hybrids that could be different.

The ideal test, but also the most inconvenient, would be to disconnect your solar while driving for a day and then take a look at the day's chart from the Victron app.  

Also, what gauge wiring do you have between the truck and trailer?  If it's standard 12 gauge, and 18' to 25'+ of wiring from truck to trailer (depending on where it starts in the truck), and the Norcold fridge pulls 15 amps, then already I think your wiring is undersized (assuming you're charging from the truck at the same rate).  My guess though is that your solar is providing the bulk of what you're seeing to the batteries/fridge.  Still, traveling at night or rainy days, I think I'd want at the very least 10 awg wiring, and if I'm swapping it out for that, then of course I might as well swap it out for something more.

Edited December 1, 2020 by Overland

[Overland]

For curiosity sake, I had to go out and hook my truck up to see where the electrons ended up.  Here's where things stood with the solar disconnected, no shore power, and unhooked from the truck:

Now, with the truck connected, but not turned on:

Then finally, with the truck turned on:

Well, that's revealing.  Yes, the trailer was definitely connected since the running lights were on.  And the alternator was running - here's the truck voltage, both on and off:

                

Interesting that while the truck doesn't draw anything from the trailer's batteries, it is drawing from the house battery installed in the truck.  Makes me wonder what the deal is with the trailer.  I checked the ground wire - it's there.  I get 13.35v from power to both ground and frame at the plug, and 14.5 from the same on the truck.  So...huh.

Edited December 1, 2020 by Overland

[Overland]

OK, I figured it out.  Apparently on the F150 (I'm guessing the 2015 model and up at least), you've got to click through all the on screen trailer messages that come up, and then after a short delay  the charging relay is flipped.  So with that, I think we can safely say that on an F150, you can leave the trailer plugged into the truck with no fear of a battery drain in either direction.  

As for charging, I did the same test as yesterday.  Usage to start out was exactly the same, and with the truck finally charging, I got this -

Which is pretty much as I expected, a 3 to 4 amp charge.  I'm guessing that's about the most that the wiring will allow, since the truck's charging relay is either 20 or 25 amp - can't remember which.  So, on an 8 hour drive, I'm guessing 20 to 30 Ah of charge, assuming I could get the alternator to keep the voltage up, which I have no clue if is at all possible.    

[Ospreybob]

I called Oliver asking about the interaction between the tow vehicle and lithium system and they sent me to Lifeblue for answers.  That is a bit off putting!  The folks at Lifeblue were much more helpful.  They  offered to send a circuit diagram if I sent them an email.  Here is their reply to my request.

LiFeBlue Battery can be charged from any tow vehicle. All alternators are compatible with LiFeBlue Battery. No special DC converters, controllers or regulators are needed. This is one of the many benefits of LiFeBlue Battery. Our BMS was special designed for RV and marine market and can accept charge from many sources simultaneously, both low and high current. Our battery will charge as long as you can deliver a voltage of about 13.6 or higher to the battery.

 

Because of the very small wire size and long wire run to the 7 pin connector, it is not likely that much if any current will flow. For this reason, we highly recommend the installation of an auxiliary charge circuit like the one in the attached diagram. Your alternator will become a very valuable power source that can even replace the need for a gas generator saving cost, weight, space and the need to carry gasoline. You can idle your tow vehicle engine and run heavy loads. Some even run the air conditioner from their inverter.

 

When designing the auxiliary circuit, the less voltage drop you have, the higher the current you can deliver. Shorter distance and larger conductors decrease voltage drop. You can easily charge at 80 Amps or more with most alternators using this method.

 

Here is the diagram.

 

 

Alternator Charge Circuit.pdf

[Overland]

You can do that - that's how the house battery in my truck is wired - but I wouldn't depend on it unless you've verified that your alternator will produce a continuous charge.  Mine doesn't - after a few minutes recharging the start battery, the voltage drops.  We had a discussion on here a few months back with the LifeBlue owner about it - short version is that he and I disagree.  That may be changing with hybrid trucks, since the hybrid battery bank is constantly being charged and discharged.  That's why I'm really interested in details about the Ram e-torque, and of course the new F150 as well.

Edited December 4, 2020 by Overland

[mjrendon]

Ospreybob,

Thank you for sharing this pdf.  Did either Oliver or LifeBlue offer a solution for the TV battery pulling power from the Oliver house batteries through the 7 pin connector, besides unplugging the TV at each stop.

Edited December 5, 2020 by mjrendon

[Ospreybob]

We Nothing from Oliver, but I was asking about the lithium system and not this issue per se.  The folks at Lifeblue have been very responsive.  The best way to communicate seems to be to email them at sales@lifebluebattery.com

[NCeagle]

Posting this information here as well since related:

I found out that Oliver is not connecting the charge wire by default for owners with the LIthium package.  They recommend talking to LifeBlue about the upgraded charge circuit if the TV alternator is to be used.

[Overland]

That’s ridiculous. 

[Mike and Carol]

1 hour ago, Overland said:

That’s ridiculous. 

Liability issues?

[John E Davies]

6 hours ago, NCeagle said:

I found out that Oliver is not connecting the charge wire by default for owners with the LIthium package.  

That does not meet code, an RV manufacturer cannot just leave certain standard systems incomplete on a whim. I hope they at least left the wire accessible in the electronics bay, since accessing the charge wire splice to the front harness is not at all easy.

Since they understand that all TVs will not charge their lithium package to 100% they should include ALL the necessary parts on the trailer to make that happen, like an onboard DC to DC charger. Their Zamp PWM solar charge controller will not even charge to 100%, it needs to be changed to a better MPPT unit that will, and Zamp does not even make one that is suitable. Expecting owners to run their generator or plug into shore power is just stupid. It will only generate (pun intended) more confusion and ill will toward the company.

When you are retrofitting lithium batteries into an older trailer, you expect the necessity of modifying or replacing other parts of the system. For an expensive factory installed option, you expect it to be complete as delivered. I have said it before, until their lithium package is able to operate at 100% when not connected to shore power, I would never recommend buying it.

John Davies

Spokane WA

Edited December 8, 2020 by John E Davies

[bhncb]

12 minutes ago, John E Davies said:

in the electronics bay

😂

[Overland]

1 hour ago, Mike and Carol said:

Liability issues?

I don't know what the liability issue would be.  The problem with tow vehicles charging lithiums exists with lead acid also, just most people don't realize it.  The issue with power from the trailer flowing back to the tow vehicle seems to only exist with certain tow vehicles and isn't exclusive to lithiums.  Nothing is going to get hurt either way from the small amount of power that's flowing - Oliver should just tell people not to expect much charge from their tow vehicle due to the wiring and leave it at that.  If people want to modify their vehicles and trailers for a better charge, then that's up to them to do the research and do it right.

A liability issue might be pointing owners to a specific solution, if it turns out that solution was incorrect.  

Edited December 8, 2020 by Overland

[NCeagle]

25 minutes ago, John E Davies said:

When you are retrofitting lithium batteries into an older trailer, you expect the necessity of modifying or replacing other parts of the system. For an expensive factory installed option, you expect it to be complete as delivered. I have said it before, until their lithium package is able to operate at 100% when not connected to shore power, I would never recommend buying it.

I went for the Lithium package, but I was fully aware of the limitations, so I'd still recommend it for folks if they can live with the limitations. 

The DC to DC charger has nothing to do with Lithiums specifically - it's the best way to charge any type of battery from a TV to a travel trailer due to the distance the batteries are from the generator.  So I'm ok with no charging from the TV charge wire - it wouldn't charge any batteries to 100% unless you drove 5 days non-stop. 

Since there's an upgraded 3000W inverter, the 30 Amp Zamp controller is definitely the weak link in the system, and my thought process was it's not a super expensive component and it should be pretty straight forward to swap out when the time comes.  I was planning on using some of my tax credit to upgrade to a MPPT solar charger next year if they are truly more capable in smaller solar systems. 

[bhncb]

Leaving the charge line disconnected may have been advised by Lifeblue to shield them from liability for battery damage due to inadvertent discharge by leaving a tow vehicle connected. Short sighted but certainly the cheapest way out.

[BackofBeyond]

1 hour ago, bhncb said:

Leaving the charge line disconnected may have been advised by Lifeblue to shield them from liability for battery damage due to inadvertent discharge by leaving a tow vehicle connected. Short sighted but certainly the cheapest way out.

Perhaps -

From my experience  - the electronics in todays TV's are much more complicated than ever - the buss systems and communication across the buss and  between the various modules and control circuits are subject to damage from  unrecognized voltage. Hi/low, not expected, whatever - I know where the OEM would be if I brought my TV in because it no longer functions correctly due to a damaged module somewhere. 

The cost of replacement for a simple ECM could run into the stratosphere. I would think - regardless of battery type - the RV manufactures would  have develop their systems to protect not only the OEM systems but also the accompanying TV systems. A simple one way flow system seems doable - the DC to DC chargers do this - Or as in this instance maybe  cheap out - just cut the  charge channel out entirely. 

My $$ is with the no charge from the TV. Yes  -ridiculous.

[Fritz]

9 hours ago, NCeagle said:

I found out that Oliver is not connecting the charge wire by default for owners with the LIthium package.  They recommend talking to LifeBlue about the upgraded charge circuit if the TV alternator is to be used.

On 12/5/2020 at 5:57 AM, Ospreybob said:

We Nothing from Oliver, but I was asking about the lithium system and not this issue per se.  The folks at Lifeblue have been very responsive.  The best way to communicate seems to be to email them at sales@lifebluebattery.com

I've been learning lots from these solar/battery/charging threads, but still feel confused, although perhaps confused at a slightly higher level than before 🤔.  

So, I wrote to LifeBlue about charging using a DC to DC charger: "I was shown the LifeBlue electrical diagram for increasing charge current to LifeBlue batteries in an Oliver trailer.  How does this compare to using a Redarc DC to DC charge controller (e.g., https://www.etrailer.com/Battery-Charger/Redarc/RED96FR.html)?  

Here is his response: "We don’t recommend any external DC converters. If you use the right size wire for the circuit, the battery will charge."

So my question is this: Is charging the LifeBlue batteries from the TV "simply" a matter of having a large-enough wire to carry adequate current to the trailer (and from the front of the trailer to the batteries), or is there a benefit from an external DC converter (which is what I understand the Redarc charge controller does) to fully top off the batteries.  Larry, if you see this, perhaps you could weigh in on why you don't recommend an external DC converter. 

[NCeagle]

15 minutes ago, Fritz said:

Larry, if you see this, perhaps you could weigh in on why you don't recommend an external DC converter. 

@LiFeBlueBattery  I don't know if this tag helps, but last time I used it Larry saw it and responded pretty quickly.

[LiFeBlueBattery]

1 hour ago, Fritz said:

....So my question is this: Is charging the LifeBlue batteries from the TV "simply" a matter of having a large-enough wire to carry adequate current to the trailer (and from the front of the trailer to the batteries), or is there a benefit from an external DC converter (which is what I understand the Redarc charge controller does) to fully top off the batteries.  Larry, if you see this, perhaps you could weigh in on why you don't recommend an external DC converter. 

Hi Fritz,

Yes, a large enough wire and the other components is all that is needed. The charging system we recommend in the diagram has been used successfully by us for nearly 2 decades in every kind of tow vehicle. The DC converter you linked to only supplies 12 Amps maximum. That will take a very long time to charge the batteries.

I view DC converters like this: you have 100 feet of 1/2" garden hose. You only get a trickle of water out of the end. You want more water (power) so you buy a high pressure pump (DC converter) to try and boost the water volume (current), stressing the hose in the process. Why not just use a larger hose (wire)?

Someone was asking about the E-Torque system. It has a 3 kW 48~12 DC converter. This is used to recharge the chassis battery and provide for all 12 Volt vehicle loads. There should be ample power for charging the house battery. I recommend consulting with the manufacturer as to where to tie in to the 12 volt system for auxiliary battery charging.  

I know there was much discussing in this thread. Let me know if there is a specific question and I'll try to help.

Happy Trails!

Alternator Charge Circuit.pdf

[LiFeBlueBattery]

4 hours ago, bhncb said:

Leaving the charge line disconnected may have been advised by Lifeblue to shield them from liability for battery damage due to inadvertent discharge by leaving a tow vehicle connected. Short sighted but certainly the cheapest way out.

LiFeBlue Battery did not make any recommendation to leave the charge circuit disconnected. We did advise that the customer install a disconnect solenoid as shown in our auxiliary charge circuit diagram. See example of the solenoid in attached photo.

We do not recommend connecting the 7 pin charge circuit without an isolation device controlled by the ignition. Your trailer charging system can reach 14.6 Volts. This voltage would be connected to the tow vehicles electronics. Check with your TV manufacturer for their recommendation.

Edited December 8, 2020 by LiFeBlueBattery

[mjrendon]

28 minutes ago, LiFeBlueBattery said:

Your trailer charging system can reach 14.6 Volts. This voltage would be connected to the tow vehicles electronics. Check with your TV manufacturer for their recommendation.

Larry,

Thank you for responding with LifeBlue recommendations. 

My understanding is that typical alternators produce 15 volts for charging the lead acid battery.  It would seem that 14.5 volts from the trailer would not be unusual because of this.

[LiFeBlueBattery]

1 hour ago, mjrendon said:

Larry,

Thank you for responding with LifeBlue recommendations. 

My understanding is that typical alternators produce 15 volts for charging the lead acid battery.  It would seem that 14.5 volts from the trailer would not be unusual because of this.

I was referring to modern vehicles with complex electrical systems. Back feeding high voltage when the engine is not running may trigger fault codes or worse may be harmful.

[bhncb]

1 hour ago, LiFeBlueBattery said:

Someone was asking about the E-Torque system. It has a 3 kW 48~12 DC converter.

But the converter output voltage is regulator variable between 13.3 -14.7V, depending on temperature, and actual wattage is dependent by engine speed. This makes it equivalent to a smart alternator.  Just running a bigger wire without a DC-DC changing control device at the end isn't going to overcome the low voltage issue. 

[Overland]

I would think that all modern vehicles would charge at 14.4 or higher. Mine is typically 14.6 to 14.8 when charging. Even if they don’t produce that voltage on their own, I’d assume that they could handle being jump started from a vehicle that does. 

[Overland]

1 hour ago, bhncb said:

But the converter output voltage is regulator variable between 13.3 -14.7V, depending on temperature, and actual wattage is dependent by engine speed. This makes it equivalent to a smart alternator.  Just running a bigger wire without a DC-DC changing control device at the end isn't going to overcome the low voltage issue. 

Exactly. Here’s a chart from a 30 minute trip I just made. This is from the battery monitor on an AGM house battery that I have under the back seat of my truck. It’s connected to the starter battery with 2 awg cables and a Victron Cyrix smart relay.  I have a 12 volt fridge attached to the house battery, which is the amperage load that you see on the chart.  I had auto start/stop disengaged.

In this case, I had just made another short highway trip that had already fully charged my start battery, so you don’t see a prolonged period at 14.6+ volts are the start. The house battery was at about 85%.  You can see that the voltage goes into the 14’s for just a brief period before settling in at 12.8 or so. The spikes at the beginning of the drive are in stop-go traffic. (The truck has electric assist on the brakes so those are the spikes.) You’ll see that it evens out for a bit once I get in the highway, but then jumps suddenly to around 13.4 volts. That’s when I turned on my headlights. (BTW, that’s been a GM owners trick for a while to get their voltage up to a charging level.)

So you can see that modern electrical systems only provide the voltage that the truck needs at any given time. They do this regardless of what other load you add to the system.  Unfortunately, while I may be able to trick the system into providing 13.4 volts, that isn’t enough to charge lithiums, since I’d probably only see 13.2 or less at the battery. So yes, a B2B charger is absolutely needed.