Hot wire to Toad battery

[happy]

Some discussion about flat towing our 2021 Bronco concerns the electric brake booster being disconnected by the Bronco's Battery Monitoring System (BMS) after a preset time of towing. Some say connecting a charging wire to the Toad battery will prevent the BMS from turning off the electric brake boost.

So my question: Is it safe/proper/OK to run a hot wire from the coach battery directly (through the proper connect/disconnect for towing) to the Toad battery?

I want to run a larger wire than is commonly available in a 7 pin connector.

[ducksface]

Why do you want to run a bigger wire?
Bigger is not always best. Sometimes it's just bigger.
And
I would be careful of opinions on powering a vehicle few know about by usurping a computer control.
If ford doesn't have a kit...you decide.
Do the slightly wrong thing and its not warranty work, it's $3,500 and a nine month wait.

Punchline:
Ask on the bronco forum to get a better answer, then weight that answer.

[DavidEM]

I too would use pin 4 of the 7 pin connector. It typically is 10 gauge protected by a 30A TV fuse. The Toad's battery would be just like a trailer battery. Pin 4 will only charge at 5-10 amps because of the voltage drop in the long run up to the TV's alternator or battery. But 5-10 amps should be plenty.

David

[Sappy2]

If it is NOT a sport model, I would check page 308 of owners guide for what Ford would like you to do.

[16ACE27]

Yes you can run that wire if you want; fuse it on both ends.

But how/why would the BMS even know it was connected?

[happy]

DaveEM the BMS shutting down of the electronic brake boost is well known and the recommendation to run a charge to the battery is for more amperage than a 7 pin typically carries. That 10 ga is a little small. I do appreciate the other suggestions and recommendations.

16ACE27 the Bronco is a mystical beast. The issue is that after prepping for flat tow the systems on the engine we have provide brake boost for about 45 minutes after shutting the door. At that point the BMS begins shutting off electrical power and the brake boost is one of the first to go. This was easily found out by those who tow and soon had less brake power. One easy fix is to use the FOB to lock/unlock the doors and reset the BMS for another 45 minute period. Another has been touted by several companies who are seeking to find solutions and that is to keep a charge on the battery during towing.

Why is it that some many of you replied as if you have never heard of this problem? Oh yeah, it is probably because you have never heard of this problem since most vehicles that are engineered to flat tow have engineers that actually know what they are doing. It is hoped that Ford will offer a fix for this problem soon.

[16ACE27]

Originally Posted by happy

DaveEM the BMS shutting down of the electronic brake boost is well known and the recommendation to run a charge to the battery is for more amperage than a 7 pin typically carries. That 10 ga is a little small. I do appreciate the other suggestions and recommendations.

The amperage coming through the charge wire is dependent on the voltage difference between the TOAD battery and the charging voltage minus the voltage drop in the wire. If your BMS/brake boost needs amperage it can easily pull it from the TOAD battery regardless of what's available from the towing vehicle battery.

[ducksface]

Originally Posted by 16ACE27

The amperage coming through the charge wire is dependent on the voltage difference between the TOAD battery and the charging voltage minus the voltage drop in the wire. If your BMS/brake boost needs amperage it can easily pull it from the TOAD battery regardless of what's available from the towing vehicle battery.

Absolutely what I thought
But
If the stupid thing is looking for voltage and the towed drops below say an arbitrary guess of 13.8v, it will cut off.
But
If this is true and your alternator craps out, will you lose your brakes?

In any case, ask at the bronco forum.
Our speculations can cost you plenty.


It a seems a bit...off ...this bigger wire thing.

[happy]

16ACE27 it works Exactly that way for right at 45 minutes. Then it does not.

It would take another couple of paragraphs to list all the people and ways that are being looked at to overcome this issue. A wire fused on both ends is one I am hoping to try.

[happy]

If alternator goes out we won't lose brakes per se, but would lose brake boost.

This is why so many auxiliary tow brakes systems are being affected. Ones such as Ready Brute are still affected but to a less degree.

[ducksface]

Has the Bronco forum been to a tuner to see if they can drop that requirement/voltage from the computer?


That seems easiest. Turn off the switch that turns off the switch or drop the parameter to 11 volts.
It's too obvious for this to not have investigated and proven impossible.

[DavidEM]

OK, I guess I can understand that when the Toad's battery voltage drops below 13.8 then the brakes stop working. The 7 pin connector won't supply enough voltage to prevent that.

Another way is to install a 10-20 amp DC to DC charger in line with pin 4 of the 7 pin connector and located near the Toad's battery. The DC to DC charger will boost the voltage at the battery so it will charge at its rated amp rating. Once the Toad's battery gets full, I would hope that the DC2DC keeps the voltage above 13.8 but don't know for sure. Maybe it drops to a float in the low 13s.

David

[Bill Johnson]

Originally Posted by happy

If alternator goes out we won't lose brakes per se, but would lose brake boost.

This is why so many auxiliary tow brakes systems are being affected. Ones such as Ready Brute are still affected but to a less degree.

If you run a wire to the battery in the Bronco it is only going to charge at the rate of your house batteries. If you have 160 amp alternator its not going to send 160 amps to the battery, only what the house batteries need, so if the house batteries are charged and the Bronco battery is charged it will be a very low amperage going to all the batteries, just what they need to stay charged

[ducksface]

If this can not be resolved, will you trade-in the Bronco or buy it a trailer?

[Bill Johnson]

Originally Posted by happy

Some discussion about flat towing our 2021 Bronco concerns the electric brake booster being disconnected by the Bronco's Battery Monitoring System (BMS) after a preset time of towing. Some say connecting a charging wire to the Toad battery will prevent the BMS from turning off the electric brake boost.

So my question: Is it safe/proper/OK to run a hot wire from the coach battery directly (through the proper connect/disconnect for towing) to the Toad battery?

I want to run a larger wire than is commonly available in a 7 pin connector.

Since it has the same chassis as the Ford Escape they share many mechanical components, including their basic underpinnings and their powertrains. Do they have a fix for the Escape?

[happy]

Duck, someone posted a few attempts with Forescan and found it messed with other things.
The Bronco (most new vehicles) are 2% mechanical and 130% electronic!! No we won't trade or sell, as the Ready Brute or a similar "surge" type brake system can be workable and there is the "every 45 minutes" lock the door with the FOB as you drive down the highway fix.

Bill Johnson thanks for the input about charging because of what you said the Dc to DC charger DavidEM mentions maybe needed. Sure wish this was simple, but I'm not alone.
I've camped out on the Bronco forums and joined the ranks of the Amazed That Ford Did that Club.

I believe the Bronco Sport is built on Escape model. The Bronco is completely different and built on the Ranger model. Bronco Sport is a completely different vehicle in size, engines, everything. They share the Name so it is confusing.

[Chateau_Nomad]

Technology on new vehicles is sometimes a great convenience... but when things go awry it can take you down a VERY DEEP rabbit hole! Good luck!

[Bill Johnson]

Originally Posted by happy

Duck, someone posted a few attempts with Forescan and found it messed with other things.
The Bronco (most new vehicles) are 2% mechanical and 130% electronic!! No we won't trade or sell, as the Ready Brute or a similar "surge" type brake system can be workable and there is the "every 45 minutes" lock the door with the FOB as you drive down the highway fix.

Bill Johnson thanks for the input about charging because of what you said the Dc to DC charger DavidEM mentions maybe needed. Sure wish this was simple, but I'm not alone.
I've camped out on the Bronco forums and joined the ranks of the Amazed That Ford Did that Club.

I believe the Bronco Sport is built on Escape model. The Bronco is completely different and built on the Ranger model. Bronco Sport is a completely different vehicle in size, engines, everything. They share the Name so it is confusing.

Sorry didn't know you had the real Bronco. I was wondering what if you used a lithium battery because they hold their voltage till they are almost discharged. I just traded my golf cart batteries for lithium and they needed to install a new battery gauge because the lead acid one wouldn't show the amount of battery left on the lithium replacement

[happy]

I like lithium batteries. That is worth looking at.
All this input is much appreciated as I'm trying to wade in waters deeper than I am.

A battery charger is where I am headed....I think. There are several on the market designed to keep a Toad at full charge. A product already on the market suits me better than me trying come up with something.

[Bill Johnson]

Originally Posted by happy

I like lithium batteries. That is worth looking at.
All this input is much appreciated as I'm trying to wade in waters deeper than I am.

A battery charger is where I am headed....I think. There are several on the market designed to keep a Toad at full charge. A product already on the market suits me better than me trying come up with something.

What about a lithium portable power box like a Jackery or other brand that has a connection for a car battery. It could be set onto the floor or in the engine compartment and keep the battery charged while driving. Then recharge when you get to your destination and use it to power a CPAP machine, charge cell phones, power a fridge, TV just about anything