Ford Transit USA Forum banner

What is the max DC current (amps) that 2022 Transit HD350 alternator can produce continuously without overheat?

1478 58
Can someone please let me know the max DC current (amps) that 2022 Transit HD350 alternator can produce continuously without overheat?

I need this data to decide how to use chassis alternator to charge lithium battery that usually draws more current than non-lithium battery during charging.

Thanks & regards,
Lee
21 - 40 of 59 Posts

·
Registered
Joined
·
21 Posts
See also:

There's lots of info on this channel about alternator charging of lithium batteries (and general info on van conversion electrical systems). The linked video explains why folks use a DC-DC charger for lithium batteries.
 
  • Like
Reactions: bjch512

·
Registered
Joined
·
22 Posts
Discussion Starter · #22 · (Edited)
That's what I thought... but I can only speak from my own experience. So... since you DO have that... assuming you have both CCP1 (60A fuse) and CCP2 (175A fuse), it seems like Ford thinks it's possible to pull quite a bit of power from one alternator.

@bjch512, the one thing that we've collectively figgered out / concluded is that the single alternator can't deliver more than ~50A at idle (depending on temps and such). Those trying to get more with a single usually do a high-idle setup.

So your answer goes back to: easily ~150A; maybe over 200A. FWIW, the largest DC-DC anyone has mentioned here (IIRC) is a Sterling 120A. Then there are those doing a more custom charge at ~200A DC-DC. Then there's a few of us doing ~150A with DC-AC-DC - that's what we run in our rig. The max charge rate for our system is ~1.8kW. We hit that with 150A direct or a bit more for overflow. So, for our setup, getting ~150A steady is just right.
I just started searching for information on lithum battery upgrade for my RV (2023 Thor Compass 23TW that uses 2022 Ford Transit 350HD chassis). The goal is to replace coach battery in schematics below with a 300AH lithium battery. Any information/suggestions would be helpful and appreciated.

Pics below are the original schematics of this RV, and modified schematics (based on my understanding). Someone mentioned I need to replace BIM with DC-DC charger, and cannot keep both BIM and DC-DC together. Any suggestions? By the way, the GENERATOR on top is the coach generator not chassis alternator.

By the way, ISO RELAY in pic is BIM (Battery Isolator Manager) that isolates the two battery systems, chassis, and coach, in a motorhome. This prevents loads in one system from discharging both. It also connects the two battery systems together during charging. Both batteries are charged if either is being charged.


Rectangle Slope Schematic Font Parallel
Rectangle Slope Font Parallel Diagram
 

·
Registered
Joined
·
22 Posts
Discussion Starter · #23 ·
CCP1 is fused at 60A and does not have load shedding, it should be live all the time. Most people hook up to CCP2 if they have that stud since it powers down after awhile (seems a bit variable) so you won't flat your vehicle/starter battery so easily. Both CCP1 and CCP2 are connected to the vehicle battery or batteries and the batteries are connected to the alternator, so you could say that CCP1 and CCP2 are connected to the alternator with the batteries as a buffer. I'm not clear on all the battery management that the Transit performs, but it's not as simple as you might imagine. You can read the BEMM if you want to get smart on this. The BEMM for 2021 says that you can draw up to the 175A limit of CCP2 continuously, but I think that's pretty misleading. Obviously you will quickly run out of power if you draw 175A from an 60Ah battery, or dual 60Ah batteries, so you have to mostly think about what your alternator can produce. At idle on a hot day your alternator is producing about 110A and the vehicle will consume around 40A, so you have around 70A at idle to work with. If you are driving around you get more. The BEMM has the alternator curves in it.
Nice details. Thank you. I'll keep searching and studying...
 

·
Registered
2021 Transit 148 HR
Joined
·
378 Posts
Any information/suggestions would be helpful and appreciated.
View attachment 181921 View attachment 181923
You have a lot of missing fuses or breakers in that diagram, I guess you know that.

You should use a breaker between the vehicle battery and the DC2DC charger rather than a fuse so you can maintaing the system more easily. In other words you can flip the breaker like a switch to allow you to work on the downstream side of it. I don't know what the purpose of the ISO relay is in your diagram. This is not required by some of the DC2DC chargers, although it might be required by some.

The DC to DC charger does not typically take output from a generator, but it could if your generator puts out 12V. Often generators put out 110V. In that case you will need to put a battery charger in between the generator and the coach battery.
 

·
Registered
Joined
·
9 Posts
Can someone please let me know the max DC current (amps) that 2022 Transit HD350 alternator can produce continuously without overheat?

I need this data to decide how to use chassis alternator to charge lithium battery that usually draws more current than non-lithium battery during charging.

Thanks & regards,
Lee
The answer as I understand it is aprox 25% of the alternators capacity that would be a safe load. The problem is that the alternator overheats on low engine RPM not when you are driving regular speeds.
So an alternator with a full draw will overheat at idle and low RPM.
 

·
Registered
Joined
·
9 Posts
Well I have to say that it is a matter of fact! A 250 amp alternator has a safe continuous of about 65 - 70 amps under varying temperatures and RPM. Do your own research! Maybe you can check Dr. Google and find something different.
 

·
Registered
Joined
·
810 Posts
Well I have to say that it is a matter of fact! A 250 amp alternator has a safe continuous of about 65 - 70 amps under varying temperatures and RPM. Do your own research! Maybe you can check Dr. Google and find something different.
No need to google, my alternator is rarely outputting less than 125 amps and I’ve never had a problem in the years that I have been driving my van
 

·
Registered
Joined
·
1,371 Posts
60% of alternator rating is generally a safe load for long life. When pulling high amps, you do need to watch the temperature, particularly when idling. If you plan to pull a lot of amps at idle, implementing SEIC (stationary elevated idle control) is a good idea. I have temp sensors on both my alternators, this winter I’ll be doing testing to see how much power I can safely supply to my dual 120A Sterling B2Bs. I have twin alternators.
 
  • Like
Reactions: bjch512

·
Registered
Joined
·
4,955 Posts
I am drawing about 100 amps from my transit's 150 amp alternator, It has not been a problem in the six years since I bought my transit. The only idling I do is at the stop light.
The 40 amps a base model transit requires and a 60 amps for a Sterling battery to battery charger.
It is pretty hot where I live for six months a year but it is usually below 100 degree's ambient. In the Southwest somewhere I might get into trouble, I dont know.
 

·
Registered
2019 HR Cargo Oxford White 148 wb 3.7L
Joined
·
951 Posts
60% of alternator rating is generally a safe load for long life. When pulling high amps, you do need to watch the temperature, particularly when idling. If you plan to pull a lot of amps at idle, implementing SEIC (stationary elevated idle control) is a good idea. I have temp sensors on both my alternators, this winter I’ll be doing testing to see how much power I can safely supply to my dual 120A Sterling B2Bs. I have twin alternators.
Whats the highest temps that you have you seen from the alternators, and what kind of temp sensors are you using? have been looking at temp sensors. using a Infrared Thermometer Temperature Gun right now.
 

·
Registered
Joined
·
1,371 Posts
No data yet… they’ll eventually be hooked up to my Cerbo GX. They’re just thermocouple temp sensors from victron bolted to some of the bolts on the alternator case. I’m very slowly working on my build, but getting close to have the electrical system in
 
  • Love
Reactions: gregoryx

·
Registered
2019 HR Cargo Oxford White 148 wb 3.7L
Joined
·
951 Posts
Looking forward to your review, I to have a Sterling 120AB2B (old version) not hooked up yet, currently working on installing a 390 watt solar panel. Running a single 250 amp alternator, thinking of a roll your own dual alternator setup.
 

·
Registered
Joined
·
301 Posts
Whats the highest temps that you have you seen from the alternators, and what kind of temp sensors are you using?
Like @ArgonautVans, I have a Victron thermocouple sensor hooked up to a bolt on my primary alternator, which does most of the work. I have a current sensor on the secondary alternator just to see if/when it kicks on. High temp seems to be around 185F. See temperature and charging charts below from a trip to Florida this summer. Started out charging at around 145A with temps 150-160F. Spiked up to 185F right after I took a break. Ambient temp was probably in the high 90s.

Rectangle Slope Font Line Parallel
 

·
Registered
2020 High-Extended AWD EcoBoost Cargo with windows
Joined
·
4,388 Posts
Like @ArgonautVans, I have a Victron thermocouple sensor hooked up to a bolt on my primary alternator, which does most of the work. I have a current sensor on the secondary alternator just to see if/when it kicks on. High temp seems to be around 185F. See temperature and charging charts below from a trip to Florida this summer. Started out charging at around 145A with temps 150-160F. Spiked up to 185F right after I took a break. Ambient temp was probably in the high 90s.

...
Love the DATA!

What current sensor are you using and how is it connected to the Cerbo / VenusOS?
 

·
Registered
Joined
·
301 Posts
What current sensor are you using and how is it connected to the Cerbo / VenusOS?
I am using a cheap hall effect sensor for the second alternator. Unfortunately, it is not connected to Cerbo. :( I just keep the digital display stored under the drivers seat and pull it out every now and then, in case I'm idling with a heavy draw. Would love to find something I could hook up to the Cerbo.

Motor vehicle Hood Automotive design Automotive tire Automotive exterior
 

·
Registered
2020 High-Extended AWD EcoBoost Cargo with windows
Joined
·
4,388 Posts
I am using a cheap hall effect sensor for the second alternator. Unfortunately, it is not connected to Cerbo. :( I just keep the digital display stored under the drivers seat and pull it out every now and then, in case I'm idling with a heavy draw. Would love to find something I could hook up to the Cerbo.
...
Ahhh... you had my hopes up that you'd found a way to hook a hall sensor to the Cerbo! They've got a setup now to allow multiple shunts to track different loads; but I'd really prefer something simpler and cheaper.

I've got a Home Assistant instance that's ready to start doing stuff... maybe eventually, I'll get ambitious enough to do something with that for current sensors. Maybe there's a low-ish-priced ESP or Zigbee solution... I really don't want to go Arduino... I hate soldering stuff.
 

·
Registered
2022 U8U
Joined
·
653 Posts
I've got a Home Assistant instance that's ready to start doing stuff... maybe eventually, I'll get ambitious enough to do something with that for current sensors. Maybe there's a low-ish-priced ESP or Zigbee solution... I really don't want to go Arduino... I hate soldering stuff.
Doing hall sensors with ESPhome is trivial. It is a no-brainer IMO.

To avoid soldering, just get some of these:
Green Rectangle Font Hardware programmer Circuit component


https://www.amazon.com/dp/B09XM2TZVT?psc=1

They're great.
 
21 - 40 of 59 Posts
Top