Large alternator in tow package question

[Rummie]

I have the tow package with the larger alternator. My camper has a three way fridge that eats up battery pretty fast when towing with propane off. Will the larger alternator in the tow package help to keep up better with the camper needs? Or will it have the issues I've read about with smart alternators that don't always put extra power to the camper/trailer?

We haven't towed yet with the newly arrived Gladiator to test this out.

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[Kevin_D]

A three-way refrigerator is pretty much outdated, as the 12V heater to run the refrigerator didn't deliver enough power to do much more than keep cold stuff chilled; it wouldn't take anything warm and cool it off.
That being said, the 7-pin trailer connector will supply ~25A at 12V to the trailer. If the refrigerator draws over 30A, it'll blow a fuse in the JT.
I gave up using the 12V setting in my previous RV, and just used propane. My current RV doesn't even have a 12V option on the refrigerator.

Kevin

 

[ShadowsPapa]

I have the tow package with the larger alternator. My camper has a three way fridge that eats up battery pretty fast when towing with propane off. Will the larger alternator in the tow package help to keep up better with the camper needs? Or will it have the issues I've read about with smart alternators that don't always put extra power to the camper/trailer?

We haven't towed yet with the newly arrived Gladiator to test this out.

It's not an alternator that "puts extra power to the camper" - that's a function of the wiring capacity going back there. The alternator will keep up whatever is needed to keep the voltage to a certain level. They don't do anything specific with a camper. To the alternator, the camper is simply load on the truck.

Otherwise, what Kevin said.........

 

[Rummie]

Thanks guys. This is new territory for me. I had read about smart alternators not supplying the campers with enough juice. But you can't believe everything you read on the internet.

Our camper can come with a two way that is far more efficient on electric/battery. It's a compressor unit. Or it can come with an evaporator that can also use propane. The compressor works a lot better in most ways but the one offered was very small. I have found a two way that would fit pretty closely in where the three way is now. If the three way is a problem we will switch it out.

I am just hoping that it can keep food cool on a long drive on a hot day without running the battery out.

So, newbie question - what is the purpose of a higher output alternator in a tow package?

 

[ShadowsPapa]

Thanks guys. This is new territory for me. I had read about smart alternators not supplying the campers with enough juice. But you can't believe everything you read on the internet.

Our camper can come with a two way that is far more efficient on electric/battery. It's a compressor unit. Or it can come with an evaporator that can also use propane. The compressor works a lot better in most ways but the one offered was very small. I have found a two way that would fit pretty closely in where the three way is now. If the three way is a problem we will switch it out.

I am just hoping that it can keep food cool on a long drive on a hot day without running the battery out.

So, newbie question - what is the purpose of a higher output alternator in a tow package?

It's needed to generate enough power for the larger electric fans. Cooling was one of the larger issues getting the tow rating on these up. They needed more cooling, more air flow, bigger fans - and it took a larger alternator to power the larger fans (and of course there's all the other electrical goodies in some of these.

 

[Rummie]

It's needed to generate enough power for the larger electric fans. Cooling was one of the larger issues getting the tow rating on these up. They needed more cooling, more air flow, bigger fans - and it took a larger alternator to power the larger fans (and of course there's all the other electrical goodies in some of these.

Ahh, makes perfect sense now.

 

[Jaxmax]

It is there to help with the additional load required by charging the trailer , and addtional lighting load with trailer running and brake lights, a standard alternator might not be able to keep up with the load and battery would start dropping.....jack

 

[Kevin_D]

200+ amp alternators are funny...
My old Ford had a 75-amp alternator, had several power options, towed a trailer, and never ran the battery dead.
But it didn't have Nav, MP3 player, computers, USB ports...

 

[Kevin_D]

I am just hoping that it can keep food cool on a long drive on a hot day without running the battery out.

You shouldn't have a problem keeping the camper battery charged.
You will probably have a problem with the 12V operation of the refrigerator keeping stuff cold on a hot day. Mine never did. But it was in a 1990 motorhome, too.

Kevin

 

[Oil_Burner]

I have the tow package with the larger alternator. My camper has a three way fridge that eats up battery pretty fast when towing with propane off. Will the larger alternator in the tow package help to keep up better with the camper needs? Or will it have the issues I've read about with smart alternators that don't always put extra power to the camper/trailer?

We haven't towed yet with the newly arrived Gladiator to test this out.

My 4-door Norcold fridge in my motorhome which runs on propane when the motorhome isn't plugged into 120/240V AC. It has two 120V heaters internal to the fridge to keep everything cold when on AC power, each one is 225W (450W total).

If your fridge was pulling anything close to 450W on DC, you would need ~35A at a nominal battery voltage of 12.6V, which is more than you can draw from your 7-pin connector on the Gladiator.

I recommend using propane for the fridge when towing. Fridges really don't use much propane compared to some of the other appliances, like a propane hot water heater or a propane furnace.

I've left my motorhome fridge on propane for at over one week, and didn't really notice a substantial drop in level.

 

[Kevin_D]

My 4-door Norcold fridge in my motorhome which runs on propane when the motorhome isn't plugged into 120/240V AC. It has two 120V heaters internal to the fridge to keep everything cold when on AC power, each one is 225W (450W total).

If your fridge was pulling anything close to 450W on DC, you would need ~35A at a nominal battery voltage of 12.6V, which is more than you can draw from your 7-pin connector on the Gladiator.

IIRC, the 12V on my 3-way 'fridge was only 120W. Small wonder it didn't work for crap.

 

[ShadowsPapa]

200+ amp alternators are funny...
My old Ford had a 75-amp alternator, had several power options, towed a trailer, and never ran the battery dead.
But it didn't have Nav, MP3 player, computers, USB ports...

Modern engine electronics need CLEAN power and a lot of it. Fuel injection alone demands very clean stable power without ripple.
The computer/PCM, injectors, electric pumps, all of it, there's a lot of demand just from the engine alone.
My 4.0 in my SX4 tossed me a check engine light a few days after initial install and some driving around. I noticed the volt meter wasn't keeping up where it should be.
One of the two 60 amp fuses had blown - I'm thinking I may have done something during the install and hooking up the massive amount of wiring in that car when I converted things -the battery was staying up but the system didn't like having only partial power. These things toss a fit when voltage gets low.

A number of AMCers on our forum have converted to EFI and have found they needed more than their 55 amp alternator to keep up. I have some training docs in my stash that talk about powering early EFI and computer systems and how to diagnose issues - and the big talk was alternators.
It's one reason I buck the norm and scope alternators I work on, especially if I have any hint the owner of that car may do EFI conversions later.

Yes, you have trailer lights, likely a battery at the camper, maybe accessories running back there, the fans/cooling system, etc.

For a vintage car anything over about 60 is a total waste and pure bragging rights (or someone fell for the marketing bull crap out there), but for anything with a PCM and EFI........ you need more.

 

[EJS]

We have a 2021 KZ Connect and we cool the 12v only fridge down at the house the morning we set out. By about 3pm or so both the fridge and freezer are ready to be filled. We leave the fridge on while we drive and everything remains a good temp. We have done this several times with our Gladiator and have had no issues.

 

[ShadowsPapa]

I could make ice in my camper's fridge when I had it (sold it a few years ago). It worked fine on propane, battery, or campground power.

 

[InvertedLogic]

Modern ECUs draw somewhere between 20-40A by themselves which is pretty crazy

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