The batteries are in parallel and all loads connected to the pair. CCP1 is powered all the time while CCP2 only is powered while the engine is running and only a short time after the engine shuts off. CCP1 is limited to 60A to minimize the battery drain while the engine is off. Even at 60A on CCP1 you will nearly kill the pair of batteries in about an hour if the engine is not running.

Another thing to consider is that the cabling from the batteries and the fuse holder for CCP1 are not likely sized to handle a higher load.

 

I understand that starter battery with CCP1 powers all 12v electrical so perhaps that's why it's paired with 60a fuse.

Not true. Both batteries identical and are wired in parallel, and both batteries support all loads. I believe that may be different in Europe, but this is the USA forum... More discussion on CCP1 below.

with both alternators being HD 250amp, why is CCP1 is 60a fused and CCP2 is 175a fused?

would it be ok to swap out the 60a for a 174a ahead of CCP1?

CCP1 and CCP2 are quite different.

CCP1 is "always on", even if the key is off. The value of CCP1 is that you can use it anytime. It does have a 'battery guard' protection, Ford will turn it off when the battery gets low, but generally - it's always on. That's pretty neat. It would not make sense to pull more than 60amps with the engine off.

CCP2 is tied to the engine-run. 175a is available when the Engine is running, and shuts off a short time after engine shut-down. (actually up to 30 minutes later).

Given the differences, they aren't interchangeable. You can't just swap one for the other. Both are built into a module underneath the driver-seat, and the circuits are very different. It would be major-surgery to change them both to 175 amps.

It's also the case that while each Alternator is 250amps, the overall capacity remains 250 amps, and that needs to support the operation of the vehicle, which can be estimated at 50-70 amps. That means even with Dual Alternators, there's at most somewhere around 190 amps available after powering the Ford system. Pull any more than that and you're eating into the batteries. Busbars and wire-sizes under the seat are not sized for 350+amp loads.

From the testing that some forum members here did, the value of dual-alternators is that the system is much less likely to have load-shedding events while idling.

Here's the Ford RPM to Alternator power chart: At Idle a single alternator only has about 80amps available, and that also needs to power the van system itself. Dual alternators doubles the low-RPM available amps. (note, those are Alternator RPMs which are 2.7X engine RPM). Typical idle RPM in yellow.

That said, I have a fairly big battery (8kwh), and I can pull 120amps from CCP2... I'm pretty happy with that. There are easy ways I can pull more :
Easy :add 50 amps to CCP1
Medium: wire directly to battery, implement load-shedding
Hard: Add aftermarket alternator

But... I just don't think that juice is worth the squeeze. Maybe my opinion there will change when I get my second 8khw battery installed.

 

Fantastic review, @chicagoandy. I'd add that another likely value/intent with the dual alternators is to keep load and heat distributed between them - even above idle. As you said, they don't increase the available power, really. Just available power at idle.

 

......CCP1 and CCP2 are quite different.

CCP1 is "always on", even if the key is off. The value of CCP1 is that you can use it anytime. It does have a 'battery guard' protection, Ford will turn it off when the battery gets low, but generally - it's always on. That's pretty neat. It would not make sense to pull more than 60amps with the engine off.......

On my 2020 cargo, CCP1 has no load shedding or 'battery guard' protection. You can totally drain the dual batteries if something is drawing power from CCP1 for too long. DAMHIK this .

CCP2 is tied to the engine-run. 175a is available when the Engine is running, and shuts off a short time after engine shut-down. (actually up to 30 minutes later)........

Just to clarify this. CCP2 is monitored by the built-in load shedding/'battery guard' function. The more load on CCP2 with the engine off, the sooner CCP2 goes offline.

Again, this info is based off working on my 2020 cargo with dual batteries. Earlier years are different and later years or trims may be different.

 

BEMM from 02/25

At "Idle" 700 RPM, the alternator has about a 2.7 ratio; Almost 1900 alternator RPM. With a hot engine, at idle, you can easily draw 120Amps off the second alternator.

 

CCP 1 is always hot, no load shedding, manual switch control and user participation required to avoid battery drain.

CCP2 is on at door open, will time out unless key is on, load shedding and timed out after key off. Open the door and it repowers. Manual switch optional and user engagement is not required.

 

I kinda love how the CCP1/CCP2/dual-alternators/dual-batteries topics have become the new ground topics.


So many of us struggled to figure out exactly what works and what doesn't - in spite of less-than-clear or at least less-than-obvious documentation - but it's certainly still a bit of a mystery in some ways.

Are there two separate #1 or #0 wires - one from each alternator? I'm still not sure - haven't traced the two that show up under the driver's seat.

How much damage are we doing to the alternators idling with 120A or 150A (or larger) loads? I guess the heat-tests on each alternator are the only way to test at this point?

Can/could it theoretically deliver 300A (just to pick a number larger than 200A or 250A) when the van is in motion and the alternators are cool enough? I don't want to melt wires trying to find out... we did have that one person who reported melted wires. 🤔

I'm going to a combination of DC-DC (Orion XS1400) /with/ the Giandel inveter-shore-power setup for the new van... if it works well, retro-fitting it to the 2020 van. Just to see how well it deals with 180A or so... 🤞

 

1/0 coming off the alternators, any draw above 180a to house (plus 60a to operate van) and the 1/0 wires heat up.

if you plan to pull 180a or more i recommend upgrading oem wires.

i am 250a charge capable, but i normally pull 180a while driving without the voltage dropping. 130a at idle/stop lights.

3x orion xs off ccp2
1x cl12-100 to battery

 

1/0 coming off the alternators, any draw above 180a to house (plus 60a to operate van) and the 1/0 wires heat up.

if you plan to pull 180a or more i recommend upgrading oem wires.

i am 250a charge capable, but i normally pull 180a while driving without the voltage dropping. 130a at idle/stop lights.

3x orion xs off ccp2
1x cl12-100 to battery

Is there a single 1/0? Or two? It looks like there's two coming into the panel... but I've never checked. And, no... I do NOT intend to push beyond 200A - and keep it below 180A for sustained.

 

3x 1/0 come from the engine to the panel under the driver seat. One to each alternator and one to the starter.

the main alternator seems to always push more power 60/40 split

The cl12 connected to the battery is a current limiter, so it pulls what’s available or if i put a heavy load on the rear system.

i also did the cl12 to the starter battery so i can get 100a charging when i use remote start. CCP2 doesn't turn on with remote start.

all of my chargers are under the passenger seat. Cant upload.

With chargers you have to look at the output and that sterling is only ~100amps output. Plus once you start stacking dumb chargers they interfere with each other.

 

3x 1/0 come from the engine to the panel under the driver seat. One to each alternator and one to the starter.
...

Thanks for confirming. I see the three coming into the panel... but not clear from there, of course.

I thought of you when I ordered the XS1400 unit, of course: just a different setup for our 12/24 combo.

 

As I understand it, even a single alternator cannot be overheated and damaged by heavy loads on CCP2. Load shedding should happen before the alternator becomes too hot. Can anybody confirm that?

I can monitor on Forscan lite how much amps the alternator can deliver maximum at the moment. This is usually between 150 A (at idle) and 240 A (at higher RPM) and decreasing as the alternator warms up. Does the alternator really has a temperature sensor? Or is maximum output calculated from RPM, and other parameters like amps drawn over some time and ambient temperature?

I guess that load shedding will happen if more amps are pulled than the calculated maximum?