"Toad" Charging Issue

[Jabber Jaw]

Coach: 2020 Newmar Canyon Star "3710"
Chassis: 2019 Ford F-53, 26,000 GVWR with V-10
Toad: 2017 GMC Terrain SLT, 4 cyl.

Ford Dealer connected the "power" line from the chassis to the 7 way. So there is current.

rvi "Toad" charger installed and connected to toad battery.

rvi3 brake unit used in "Toad".

Everything works fine, BUT!

When traveling, if I don't stop, start the toad, and let it run about 5-8 minutes, at the end of the day, the "toad" battery is drained.

When this occurs, if I leave the "Coach" running, after about 15 minutes, there is enough "juice" in the battery for the "toad" to start. Let it run a while, and it will start every time; until after another day of travel.

Battery was replaced less than a year ago, as I thought the original was just too old! NOT....the new one does it too!

If I drive more than 3 hours without stopping to start the "Toad", battery does not have enough "juice" to start the car!

This had been an issue now for about 18 months, and I just kept putting it off! Sometimes I just get "lazy", I reckon!

So, what's the opinion? Ideas? Solution?

I ask, because I'm leaving for a 64 day, 6,500 mile trip out West, the end of June, & would like to not have to deal with this issue, but if I can't get it corrected, guess I'll have to just deal with it!

[HarryStone]

How is the charger connected to the charge line from the RV? Sounds like the toad is not charging while you are driving down the road.

[Mighty_J]

That toad battery charger from RVI should be able to trickle charge or provide up to 10 amps if it senses a parasitic draw. Seems like it might be a problem with the charger hook-up. If I understand your note correctly, if the toad is still connected to the coach and in “tow mode” but you’re not moving it will provide enough charge in about 15 minutes to start the vehicle.

That means the draw when you’re moving is greater than the amperage provided by the charger. Is it grounded properly? Do you have the control monitor so you can check what mode it’s in when in motion? What do the LEDs on the charger tell you is happening?

[pasdad1]

The RVI tablet will show real time battery voltage on the “toad charger” device….. what does it show ?

[Isaac-1]

We have a similar problem towing our Jeep Cherokee, particularly on roads with a lot of curves, my guess is this is because it has an electric power steering system that must be active while in tow mode to prevent "death wobble", this is done by flipping on a special switch that is retrofitted to allow flat towing. My guess is the power draw for the EPS system is more than the charge line can supply.

[keef033]

This is interesting. We also tow a Jeep Cherokee with the power steering harness fitted. I have spent a lot of time with RVi support over this very issue. I took pictures of the tablet at various times and sent it to them. I was in Colorado Springs so I went up to Castle Rock and visited with them. They gave me a new TBC+. It seemed too work better, but I am not convinced it supplies enough juice for the Jeep. I also have the RVi3 brake connected.
I disconnect the brake and the power steering overnight. But I still run the Jeep in the morning and when I stop.

I never see more than 2amps being used and rarely over 12.5v. It may go up to 13+v momentarily. Usually it is charging at around 1.2amps and voltage just above what my battery is reading.

The RVi support is very good. They said that what I am seeing is how's it is meant to work, but I think I would be down below 12v at three end of a day travel.

I had my battery tested and it's is in great shape. Only 1yr old as well.

I have attached the pics of my tablet that I sent to RVi. The numbers in green show the time of day.

[TeJay]

TEST, TEST, TEST!!!! I don't know all that is happening with your situation but this I'm sure would be my very next step. I'd want to know what is charging and voltages at batteries before chargers start working and after they start working.

STATIC VOLTAGE is the battery voltage checked when the battery is just setting doing no work. You can determine a lot with this information.

If your RV is running and should be charging the TOAD battery. What is the voltage that is being sent to the TOAD. Check the voltage (static) before starting the RV. Then check it after the RV is running. For a charger to overcome the resistance of the battery to be charged it needs to provide at least 1 VOLT over the static charge you read when nothing is running.

If you were to drive for say 2 hours and checked the charge rate at the TOAD what is it.
What is the charge rate coming from the RV engine alternator to the chassis batteries? That to falls into the same category. If it's designed to charge any attached batteries be they house or cranking or TOAD batteries they should be a minimum of 1 VOLT above the static charges. You need IHMO to be doing some voltage checks at various point to determine what is and isn't being charged or to the extent they are trying to charge batteries.

It's always been my TEACHING position when doing electrical work always check then double using a DVOM to really ascertain/determine/know exactly what is and isn't happening with the electrical systems.

Knowing voltages is easier and will tell you what is happening. Yes current drain is important but harder to measure. This we also know. If current isn't being created or developed inside the battery electrical work is hampered. We also know immediately what we don't have. Current is what we need to do the work. The more the LOAD the more current is needed. The cranking motor requires THEE most current at 150 or so cranking amps. The voltage actually pushes the electron into the battery. Low voltage flow and low electron movement. Low electron movement and low charging.

Don't mean to bore you with facts you probably already know but sometimes it helps to hear it expressed in different ways to improve understanding.

Best of luck with this and let us know what you find!!!!
Thanks!!

[ga traveler]

The answer is easy. The dealer messed up! I have flat towed with four of my motorhomes. I wired a charge line from the motorhome battery to the towed on all four. To test for charging is easy. Read the voltage on the towed battery. It should be around 12.7 volts. Now hook up the cord to the motorhome with the motorhome plugged in or the engine running. If the towed is wired correctly, the voltage on the towed should go up to about 13.6 if the motorhome is plugged in or around 14 volts with the motorhome engine running. If there is no increase in voltage, you have no connection.

[NXR]

Originally Posted by ga traveler

The answer is easy.

Maybe not in this case. The Terrain and Equinox were essentially identical up to and including the 2017 model year. Both pull over 7 amps when configured for towing, far more than other vehicles.

While the RVi TBC claims it will produce 10 amps, it won't. There are multiple threads here including one I started that have all of the data substantiating that. It feels like the TBC thinks it's delivering current to a short circuit due to the high current drain and it "folds back" the current.

RVi supplied a couple of TBC units to me and none worked on the Equinox. I finally jumped the thing out and I've never had a battery problem since, two years. Before that the battery would be dead after about four hours it towing. Other people had the same problem with the same fix. RVi first blamed it on the AGM battery and later backed away from that.

Don't get me wrong. RVi was great to work with but there seem to be conditions that their TBC does not like.

Is it possible that the reason the toad charges at the end of the day is that it's no longer in tow mode? That you put it in Park? That would kill the drain and allow the battery to charge.

Ray

[Jabber Jaw]

Originally Posted by NXR

Maybe not in this case. The Terrain and Equinox were essentially identical up to and including the 2017 model year. Both pull over 7 amps when configured for towing, far more than other vehicles.

While the RVi TBC claims it will produce 10 amps, it won't. There are multiple threads here including one I started that have all of the data substantiating that. It feels like the TBC thinks it's delivering current to a short circuit due to the high current drain and it "folds back" the current.

RVi supplied a couple of TBC units to me and none worked on the Equinox. I finally jumped the thing out and I've never had a battery problem since, two years. Before that the battery would be dead after about four hours it towing. Other people had the same problem with the same fix. RVi first blamed it on the AGM battery and later backed away from that.

Don't get me wrong. RVi was great to work with but there seem to be conditions that their TBC does not like.

Is it possible that the reason the toad charges at the end of the day is that it's no longer in tow mode? That you put it in Park? That would kill the drain and allow the battery to charge.

Ray

Ray......

So what do you mean, you "jumped it out"? Did you bypass it and go direct to the battery? Please explain!

From your post, it seems I have the same problem.

I'm not an expert about "electricity", but if bypassing it will work, probably what I'll do.

I wonder if there's a product out there, that when installed, would overcome the "draw" from the Terrain?

Thanks to each of you, for your post! Always helpful!

[keef033]

Your experience with the RVi TBC mirrors my experience with the Jeep. It is just not supplying enough juice to keep up with the drain. I think the pics showing the drain/juice situation shows that we well.

I am going to look for a different solution as well.

[ga traveler]

Originally Posted by NXR

Maybe not in this case. The Terrain and Equinox were essentially identical up to and including the 2017 model year. Both pull over 7 amps when configured for towing, far more than other vehicles.

While the RVi TBC claims it will produce 10 amps, it won't. There are multiple threads here including one I started that have all of the data substantiating that. It feels like the TBC thinks it's delivering current to a short circuit due to the high current drain and it "folds back" the current.

RVi supplied a couple of TBC units to me and none worked on the Equinox. I finally jumped the thing out and I've never had a battery problem since, two years. Before that the battery would be dead after about four hours it towing. Other people had the same problem with the same fix. RVi first blamed it on the AGM battery and later backed away from that.

Don't get me wrong. RVi was great to work with but there seem to be conditions that their TBC does not like.

Is it possible that the reason the toad charges at the end of the day is that it's no longer in tow mode? That you put it in Park? That would kill the drain and allow the battery to charge.

Ray

Ray is right and I was wrong. I did not see the tbc. He is correct. I would install a 30 amp breaker ( if they used #10 wire) and do away with the tbc.
I have used the #10 wire and a 30 amp breaker since 1993 with zero problems.

[wolfe10]

Assuming you want to supply more amps to the toad battery from the coach chassis battery, but ONLY when the ignition is on:


Fuse (amp rating depending on wire used) at each battery positive
8-10 gauge wire for both positive and negative
From fuse at chassis battery to oversized relay (like 40 amp) from any auto parts house. Ignition hot source used to close relay.

[YC1]

The winpy charge line does not appear to be able to keep up.

The connection starts before the plug in the RV.
Then you have the connection on the inside of the RV plug.
Then the plug that goes into that socket.
Then the plug that goes into the toad.
Then the other side of the toad socket.
Then to some connection on or near the battery.

Then the power must flow back through a wimpy ground being shared by tail and brake lights.

All of those "Then's" add up to resistance/losses. They use small wires along the way and that too adds to those "thens".

Our 2012 Edge Limited was an absolute power hog. Keyless entry and invisibrake just kept running the battery down.

I have worked with vehicle electrical systems for 50 years so was not getting fooled by IR drops. Those "then" things.

With sensitive voltmeters you can add up the losses along the way.

My solution at the time was to run a separate two-wire charge line. Using an inexpensive jump start cable kit I built something to get rid of all those weak/small connections. Sure it is one more cable but fulltiming and ruining Toad batteries was a pain and not convenient at all.

We currently tow a F150 Limited and it too is a bit of a power hog.
This go-around I installed a "toad charger". This device takes the lower voltage coming in and steps it back up to something that has enough push to overcome the battery internal resistance. That is, it gets that voltage up to around 14 volts without all the losses.

Yes there is a bit of a compromise with less current available but it does work better than trying to charge through all those losses.

One needs to be sure the toad umbilical is built correctly with a decent size wire. I found in my new umbilical a wire far too light to work decently. What a joke. I did find a proper size wire in the loom and moved it.

The RVI charger has been working well for the few trips I have made and with one glance under the hood I know the status of the setup.

Sorry this is so long.

You cannot charge a toad battery without getting the voltage up to 13.5 or so at the battery. The previous poster recommending the voltage readings is spot on.

One can guess all day but without readings we are spitting in the wind except for having a half century working with stuff like this.