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MJ Heat

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I have read that the Powerboost engines come with 3 different functional starters. As I understand it the 3 starters are 1. The conventional 3.5 Ecoboost Starter, 2. The 47hp 3 phase Electric Drive Motor, & 3. The Belt Driven Generator/Starter positioned on the front of the engine. I would really appreciate it if anyone out there can shed a little light on sequence of operation/prioritization for use of the starters. Which starter is used at what time?
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Tosh

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My understanding is that there is one starter motor - the one that actually starts the engine in the usual manner (turning the flywheel with a directly connected pinion gear).

The electric drive motor does not start the engine, but will propel the truck up to a certain point (for me typically up to about 40 MPH on a flat road). When the load is too great, or the battery is too low, the ICE fires up as though you had push-started your truck (remember "popping" the clutch?).

The belt-driven generator is just that - a generator. It charges the HEV battery pack when the engine is running.
 

Oxford_Powerboost

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My understanding is that there is one starter motor - the one that actually starts the engine in the usual manner (turning the flywheel with a directly connected pinion gear).

The electric drive motor does not start the engine, but will propel the truck up to a certain point (for me typically up to about 40 MPH on a flat road). When the load is too great, or the battery is too low, the ICE fires up as though you had push-started your truck (remember "popping" the clutch?).

The belt-driven generator is just that - a generator. It charges the HEV battery pack when the engine is running.
I agree with one caveat - I believe the belt driven starter generator starts the engine most times when at a stop and when rolling at low speeds (too slow to “bump” start it). I’ve heard the traditional flywheel starter 2, maybe 3 times in 8300 miles, and each time was when the engine fired up instantly upon hitting the start button, much like a normal 3.5 would. Presumably from what I read, this was due to a low state of charge of the high voltage battery.
 

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I see your point - I've only heard the traditional starter engage when it's cold or the battery is low also.

However, I'm thinking that the belt-driven generator may not be what gets the ICE running from a dead stop, but the electric drive motor may be doing it. The drive motor is already connected to the crankshaft and transmission, whereas the generator up front is on a belt & pulley. So the drive motor has a mechanical advantage.

Also, it seems to me as though the truck starts to move forward from a stop before the ICE fires up, suggesting the electrc drive motor is engaged.

Truth is, I'm just guessing, and I haven't even gone out to look and see if the accessory belt on the generator is toothed or not ;-}
 
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MJ Heat

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I readily agree & accept that the Electric Drive Motor starts the ICE when the truck goes from electric to ICE propulsion, just like how we used to kick start our cars with stick shift transmissions 50 years ago. So how does that happen? Is the ICE spinning already with the valves open or fuel injection disabled? Is that how the ICE keeps oil pressure even though it isn’t running? Is there some crankshaft disconnect between the ICE & the Electric Drive Motor that is suddenly engaged, when it is time for the ICE to be kicked off?

Why do Ford diagrams label the “generator” as a starter/generator if it is not also a starter? And if it is a starter, when is it engaged to start the engine, instead of the conventional ICE starter?

And while I am full of questions, does anyone know the rated output of the “generator/starter”?
 

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Oxford_Powerboost

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I readily agree & accept that the Electric Drive Motor starts the ICE when the truck goes from electric to ICE propulsion, just like how we used to kick start our cars with stick shift transmissions 50 years ago. So how does that happen? Is the ICE spinning already with the valves open or fuel injection disabled? Is that how the ICE keeps oil pressure even though it isn’t running? Is there some crankshaft disconnect between the ICE & the Electric Drive Motor that is suddenly engaged, when it is time for the ICE to be kicked off?

Why do Ford diagrams label the “generator” as a starter/generator if it is not also a starter? And if it is a starter, when is it engaged to start the engine, instead of the conventional ICE starter?

And while I am full of questions, does anyone know the rated output of the “generator/starter”?
No the engine is not spinning while off. The way it is set up is engine/flywheel > disconnect clutch > electric motor > transmission input shaft. When the engine is turned off, fuel is cut and the disconnect clutch is in its “disconnected” position. When the vehicle is rolling and needs to be started, we believe (little bit of assumption here) that the clutch engages, connecting the flywheel to the spinning electric motor, effectively bump starting the engine, and then fuel delivery follows once the clutch is fully engaged

Also, the starter/generator does start the engine at low speeds and when stopped. Presumably, that is just a smaller electric motor connected to the high voltage battery that, through a belt, spins over the crankshaft to start the engine.

My understanding from other posts on this forum, one of which I can’t find but seemed to describe the conditions as stated by the service manual, is that the conventional flywheel starter is very seldom used, only when the high voltage battery state of charge is very low. (Example, last I heard it, I was idling my truck on a warm night before I got out of it last and right as the engine went to start to charge the hybrid battery I was also hitting the start/stop button. I bet I killed it before the engine even got to 400rpm lol. Next time I started the truck, it was very cold (robs batteries of power) and presumably the battery was already low, so I heard the flywheel starter engage the moment I hit the start button. This is different from normal where it energizes the hybrid system first, and then ~10 seconds later starts the engine using the belt driven starter/generator.)
 
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Handle

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Some have stated that the only time they hear the conventional starter engage is when using remote start.

I just installed a Bluetooth Ancel BM 3000 battery monitor that connects between the AGM battery posts so I can better understand when the AGM battery is charging and the voltage as well as how the Belt Integrated Starter Generator functions while driving. Only had one short drive, but it appears that the AGM is receiving charging not only while in ICE mode but also when the ICE shows no rpm. BISG are nothing new in hybrids but it’s interesting how it’s integrated into the PB.
 
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MJ Heat

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Well how about an update. Is there any PowerBoost owner out there that pays enough attention to know what starter works at what time? Or is it just impossible to know, because there is no sound or performance difference to notice?
 

JIMFOUNTAIN

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Well how about an update. Is there any PowerBoost owner out there that pays enough attention to know what starter works at what time? Or is it just impossible to know, because there is no sound or performance difference to notice?
The problem is that it is really hard to know. Pushing the start button results in a ready light. Brake on and shift into drive results in some electric humming (brake sounds different than brake + drive). Releasing the brake and I start moving downhill out of my driveway and downhill on the street. I don't get ICE ignition until I am turning and accelerating away from the stop sign on the corner. Hard to tell at that point.
 

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MJ Heat

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This Post and this thread are decent descriptions on what is used when.
Thanks for the links! There is still a lot of supposition in these threads. It doesn’t appear that anyone knows definitively when each “starter” is used. I will try to figure this out, if my truck is ever actually delivered.
 

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I’ve been running a battery monitor for the last couple days and the data is interesting. The Ancel app with the device is solid.

For my AGM it typically reads around 12.3 v sitting in driveway. With the app running, jump in the truck and push start and goes to Ready with no ICE. Volts pop immediately to 14.3-6 v. So the question is where is that voltage coming from. If the ICE drives the BISG then it s not on. So that leaves the hybrid battery system as somehow immediately supplying charge to battery. What I want to check next is be outside the truck with hood open and see if by chance the BISG is some how being powered and it’s supplying charged to AGM.

Once Ice kicks on the Ancel reads 15.3 pretty consistently

Would like to get some electrical schematics.

So far I haven’t heard the sound of a traditional starter and havnt tried remote yet to see if that’s what’s working

Ford F-150 Powerboost Starters 15134177-E8CB-46F8-9EB8-355F79E0958B
 

imnuts

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I searched through the service manual I got looking for more information. Contrary to what has been posted previously, there is no mention of the hybrid drive motor being used to start the engine. In fact, one portion said that the clutch will disengage to separate the motor and engine so the engine can be started.

Based on the manual, the traditional starter is only used in cold-start conditions. All other situations will use the belt integrated starter-generator. This includes rolling starts when the vehicle is in motion.
 

PaulGrun

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I searched through the service manual I got looking for more information. Contrary to what has been posted previously, there is no mention of the hybrid drive motor being used to start the engine. In fact, one portion said that the clutch will disengage to separate the motor and engine so the engine can be started.

Based on the manual, the traditional starter is only used in cold-start conditions. All other situations will use the belt integrated starter-generator. This includes rolling starts when the vehicle is in motion.
Resurrecting this interesting thread. @imnuts have you been able to verify that the hybrid motor is not used to start the ICE? I had always assumed that it did, but on the other hand that would lead to some interesting issues in the transition between electric drive and hybrid drive ... issues that would be easily solved by having the ICE disconnected from the drivetrain while its starting by a clutch. so o second thought, what you suggested (the starter/generator being used to start the ice) makes a lot of sense.

Someone asked above how the 12v battery gets charged. I'm pretty certain that it is charged by an inverter (actually its probably a DC/DC converter, rather than an inverter) driven by the high voltage battery. that's why you can charge up the 12v battery by letting the truck sit in the driveway idling ... no need to actually drive it anywhere. You can confirm this by pressing the start button (foot on the brake to 'start' the truck), waiting for the Ready light, and measuring the voltage at the battery - it'll be somewhere north of 14v even though the ice isn't running.

Edit: I'm wrong- it IS an inverter since the hybrid electric motor is 3-phase AC. I was assuming it's a DC motor, but that's wrong.
 
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imnuts

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Only what's listed in the service manual. I'm sure that it is technically possible to have the electric motor start the engine, but I would imagine that would be very rough on all the drivetrain components. Depending on what gear you're in and what speed you're going, you'd be trying to essentially bump start the engine and get it from 0 to 2,000+ RPM. I can't imagine a way to do that gently. I feel like it would almost be like dropping the clutch in a manual to launch, or a really, really bad shift.
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