"Newer" Ford trucks don't charge house batt's?

Just reading through all this, and being thankful I don't have all the extra pains to deal with that are on the modern rigs.....

And that’s the issue for me. When we’re traveling, most mornings I don’t know where we will be spending the night. I need maximum flexibility on overnight options, so that means I need to have a fully charged battery at the end of the day.

:):)

As long as my destination has utility power I have no issues with arriving with a depleted battery.
I am sure the Redarc does a great job at arriving with a tip top charged battery.

Kayteg1 wrote:

NRALIFR wrote:

The bottom line is that the auxiliary or house batteries need to be integrated into and treated as part of the whole system. They need to be maintained properly, and for the most part they are not,
:):)

This is blank statement, who is not applying to B2B chargers.
35 years of my RVing in more than a dozen different RV proves those chargers are not needed.
Obviously when somebody will change proven technology and install new gizmos- that is different story.
Some solar freaks make 48V systems in their RV. Go figure.

I believed the exact same thing until I bought my current truck. All of a sudden, even though I did the same thing to the charging system that I had done on two previous trucks, using higher gauge wires than I used on either of the two, it couldn’t keep up with the draw from running the fridge in AC mode while driving, and we were arriving at our destination with a severely depleted battery. That just won’t work for us.

So, what changed? That “proven technology” had changed. I didn’t ask them to do it, they just changed it and I have to deal with it. I would have preferred that things stayed the way they were, and not buy a DC-DC charger. Redarc isn’t an inexpensive brand, but there weren’t a whole lot of options available when I installed mine. There are brands now that are about half the price, but one thing I can say about Redarc is it’s a GOOD brand. It does what it’s supposed to do, it doesn’t overheat, and it can do it all day long if it has to.

:):)

StirCrazy wrote:
Just a question, I understand how the smart alts in the new fords work, just had to diagnose my system to find a broen monitering wire , but just trying to wrap my head around this, if you have your charging system in tact and you have your camper pluged in and the batteries are down that would put a load on the trucks batteries and then the PCM would raise the voltage output from the altanator to charge the batteries untill that load is not detected any more, meaning the batteries are fully charged. the system doesnt say it takes 800 watts to start the truck so thats all I am putting back in. the new fords use a two wire feed back and command loop to controle the altanatore output depending on the Voltage read directly from the battery. so if you conect your batteries in the camper to the truck batteries then the overall voltage will be inbetween them and if thats the case then the system will ramp up the charge untill all the batteries are charged.

now if there is an isolater in there that could change things, and a DC_DC charger is starting to sound like it is a more efficient way to go but the responce from the altanatore should be the same either way , unless I am missing somthing like an isolator or somthing but that wouldmt make sence to have that thee when it is designed as a system to charge the camper batteries or such

Steve

Yes you have it right. The alternator does not know anything. Not the charge level in the start battery, not the accessory load. The alternator just produces the amps required to maintain the voltage set point directed by the vehicle computer.

The newest vehicles have tuned this voltage to optimize fuel economy vs just providing tons of voltage to make sure the battery is topped off quickly. So your RV battery may not receive the proper voltage at the end of a long #14 wire for any type of fast charging. The DC-DC charger will resolve this issue for the RV battery.

Diode isolator (motorhome) could drop another half volt, relay isolator (Ford truck, some MHs) will pass through full voltage.

NRALIFR wrote:

The bottom line is that the auxiliary or house batteries need to be integrated into and treated as part of the whole system. They need to be maintained properly, and for the most part they are not,
:):)

This is blank statement, who is not applying to B2B chargers.
35 years of my RVing in more than a dozen different RV proves those chargers are not needed.
Obviously when somebody will change proven technology and install new gizmos- that is different story.
Some solar freaks make 48V systems in their RV. Go figure.

Sorry Kayteg, I just can’t agree with “something most of us don’t need” at all.

Sounds like your Sprinter has the equivalent of one built-in. I wish all vehicles did, or at least the option to have it included like inverters are now. It’s sorely needed by the RV’ing crowd, and I would happily pay the extra for it.

The bottom line is that the auxiliary or house batteries need to be integrated into and treated as part of the whole system. They need to be maintained properly, and for the most part they are not, currently. But, until they are, I’m OK with adding what’s needed myself.

People that report high heat issues either of the unit itself, or of the wires simply aren’t following the manufacturers recommendations. Yes, they need cooling to dissipate the heat. And yes, the wires have to be of sufficient gauge so they don’t heat up as well.

If your Sprinter is one of the few that treats the house batteries properly, you’re a step ahead of most of us. With its regenerative braking system you described, it’s already got a very advanced electrical system. I’m not aware of ANY light truck that has regenerative braking yet. I installed the improvements to my system in an incremental way, and know what worked and what didn’t work. That’s empirical evidence, which is good enough for me.

:):)

NRALIFR wrote:
The DC-DC charger is a much more efficient and effective means of charging an auxiliary battery.

:):)

B2B charger is having about 90% efficiency, meaning you are loosing 10% for something most of us don't need.
People who use them -report high heat generated, what brings additional issues as you can't burry the charger in storage with no ventilation.
Now how the smart alternators work need to be experienced.
In my Sprinter conversion I have smart alternator who will run the van on battery power when accelerating and put very high charge when braking or coasting.
I hook up house batteries to main battery clamp with automatic relay.
When I drive- the house draws constant 20 amp to power refrigerator and sometimes more when I turn electric water heater on.
I observe vehicle voltage and after initial charging, it keeps the voltage at 13.0-13.5V.
Meaning the Mercedes smart charging does sense draw and is not switching the system to battery power when there is constant draw.
Bottom line - it is working perfectly without B2B charger.
The smart charging system is design to save fuel and environment, but on practical side it is killing batteries every 2-3 years.
There is no free lunch.

The DC-DC charger is a much more efficient and effective means of charging an auxiliary battery. With the old vehicle charging systems, connecting an auxiliary battery directly to the alternator with big wires to minimize voltage loss worked fairly well. It allowed the aux battery to play a more direct role in the voltage sensed by the regulator, and the alternator would keep it at a more fully charged state. There was always SOME voltage drop though, so it wasn’t perfect.

On today’s vehicles, I wouldn’t even attempt to make a direct connection to the alternator. I’m pretty sure you’d end up creating problems with the ECM. I’m not familiar with dual alternator setups, but I’m going to guess that unless the ECM allows that second alternator to operate independently, which I don’t think they do, you’re still not going to get as good charging performance as a DC-DC charger.

The Redarc I’m using is connected directly to the truck’s starting batteries, and is (as far as the alternator and ECM are concerned) just another electrical load on the system. No different than using the OEM 120v inverter that comes in many vehicles today.

The way mine is installed, it’s using a charging profile suitable for my AGM battery in the camper. Once the charger turns on, it will remain on for a fairly wide range of voltage from the truck, with upper and lower limits of course. I’m assuming other brands will work the same way.

The charger only turns on when the proper voltage is present on the ignition controlled circuit from the truck. When the engine isn’t running, the DC-DC charger is off. When the voltage from the truck goes down, the charger compensates by drawing more amps, when the voltage from the truck goes up, it draws fewer amps. It ALWAYS supplies the proper voltage to the battery it’s charging for whatever state of charging it’s in.

The charger can supply up to 40 amps of charging current, and the input circuit is fused at 60 amps. It also isolates the camper battery from the truck, and does not back-feed voltage from the camper battery onto the umbilical cord.

:):)

theoldwizard1 wrote:

Bert the Welder wrote:
Thanks. I'll look him up and try to find the vid's. It certainly seems like having something like the DC2DC is needed for the "new" type batt's.

First, I worked for Ford designing Powertrain Control Systems for over 30 years until 2007, so I DO KNOW what I am talking about. Yes, I am sure things have changed since then and different manufacturers do things a bit different.

Second, there are really two issues here. Is the alternator capable of putting out sufficient voltage and current to charge a RV "house battery bank" (1 or more batteries wired for 12V nominal) AND are voltages directly from the alternator "optimal" for recharging a house battery bank.

Almost all vehicles built after about 2000 have some type of "smart charging" system. Theses systems are designed to only replace the amount of energy used to start the vehicle and not let addition loads cause the starting battery to discharge. In simple terms, immediately after starting, the voltage at the starting battery will be about 14V. Within about 5-10 minutes, that voltage will drop done to about 13.2V at the starting battery. Even with the heaviest gauge wire you can install, you are not going to get more than about 13.2V at your house battery bank ! This is not sufficient to recharge a house bank that is below 80% SOC !!

Different battery chemistries require different voltages for optimal and complete charging. Flooded lead acid is different than AGM is different than LiFePO4.

A DC to DC charger, install close to your RV's battery bank, will BOOST the incoming voltage and apply the correct voltage to your battery bank !

Just a question, I understand how the smart alts in the new fords work, just had to diagnose my system to find a broen monitering wire , but just trying to wrap my head around this, if you have your charging system in tact and you have your camper pluged in and the batteries are down that would put a load on the trucks batteries and then the PCM would raise the voltage output from the altanator to charge the batteries untill that load is not detected any more, meaning the batteries are fully charged. the system doesnt say it takes 800 watts to start the truck so thats all I am putting back in. the new fords use a two wire feed back and command loop to controle the altanatore output depending on the Voltage read directly from the battery. so if you conect your batteries in the camper to the truck batteries then the overall voltage will be inbetween them and if thats the case then the system will ramp up the charge untill all the batteries are charged.

now if there is an isolater in there that could change things, and a DC_DC charger is starting to sound like it is a more efficient way to go but the responce from the altanatore should be the same either way , unless I am missing somthing like an isolator or somthing but that wouldmt make sence to have that thee when it is designed as a system to charge the camper batteries or such

Steve