Mach E GT Battery Contactors
ฝัง
- เผยแพร่เมื่อ 19 มิ.ย. 2024
- See the contactors of a 2021 Ford Mustang Mach E GT high voltage battery. See the removal procedure and a functional demonstration of the contactors.
TIMELINE:
0:00 Start
0:08 Introduction
0:44 High Voltage PPE required for internal battery service
1:35 The location of the battery junction block with contactors
2:00 High voltage negative and positive connections
3:00 The purpose of the contactors
3:25 A measurement of the battery voltage (380 Volts) before the contactors
4:25 A measurement of the battery voltage (0 Volts) after the contactors
5:21 Different scenarios of contactor failure
6:19 DC Fast charge contactors
6:50 Removal of the battery junction box electrical connections
11:40 Removal of the battery junction box bolts
12:04 Removal of the battery junction box
14:15 MUST SEE: The partially disassembled junction block
15:10 Three different junction block and fuse options (RWD, AWD, AWD GT)
16:57 Corrections to my earlier descriptions
17:50 MUST SEE: What is a contactor? What does it do?
19:30 MUST SEE: See a live demonstration of contactor operation
22:30 The contactors are controlled by the 12-volt circuits of the battery energy control module (BECM)
23:10 MUST SEE: The high voltage sensing lines for each contactor
26:00 Four 95 nF capacitors
27:10 Contactor connections to the front and rear inverters
28:40 MUST SEE: The purpose of the pre-charge contactor and resistor
29:20 See the rear inverter connections and function
29:50 See the large capacitor in the rear inverter
30:35 Why you must charge the capacitors through the pre-charge resistor
32:35 The sequence of contactor operation for powering on the car
34:35 The current sensor
35:30 The fused electrical connections to the DC-DC converter, onboard charger module, cabin coolant heater, and electric air conditioning compressor.
36:57 The purpose of the Auxiliary Contactor
38:30 The low voltage battery electrical connection
39:10 The interlock circuits
40:00 The green circuit board for contactor control
41:50 The DC Fast charge input connection
44:10 The sequence of DC Fast charge contactor operation for charging the HV battery
45:28 Video Summary
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This video was created and edited by Professor John D. Kelly at WSU. For a full biography, see www.weber.edu/automotive/J_Kel...
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Assuming those capacitors are connected between the HV circuits and 12V ground, they are to provide an AC path for noise generated in the inverter etc. to meet EMC specs - though the HV system is isolated, if there is no AC coupling to chassis, the whole HV system will act as an antenna, radiating interference inside & outside the car. You see similar caps between the HV and LV side of mains switchmode power supplies for the same reason.
Yes, they are connected between the switched HV circuits and 12V ground. Thank you for the great information!
@mikeselectricstuff what protection would you likely see in place between HV negative and chassis earth incase of capacitor short? Or is that not an issue?
@@joshbridges8410 Not an issue, those are safety (class y) caps designed to fail open circuit.
hey, What are those capacitors called?
While I will likely never tear into the battery or the HVBJB myself, knowing what I'm driving and how it works is very valuable to me. Thank you John and Weber State. You are amazing.
Thank you very much
Great video professor! A lot of quality in depth information, even for a ford master tech like me who has hands on experience with Mach-e’s for the last couple months.gotta say you break it down way more and better than fords web base training and the hv battery repair class, thank you! I’ve replaced a handful of HVBJBs already mostly all in GTs or standard and with extended range battery, and I’ve been dying to open one up to see how they tick like you just did but ford has been calling them back almost as fast as I take them out. Thank you for showing the insides.
A few things I’d like to share…..
The recall is a module programming that will modify contactor performance and ford is hoping will save the hvbjb from having to be replaced. But software will not 100% fix hardware and some contractors are still failing, so much ford released a tsb this week to replaced hvbjb.
That leads to my next tid bit of Info, you mentioned electrify America maxes out at 350A which is under the dc fast charge rating of the Mach e, but the dc contactors can’t handle that even though it’s working it’s rating. All the failures I’m seeing are welded positive dc charge contactors after charging at an electrify America station…..
Finally i hope I didn’t miss you mentioning it, but it should be mentioned that both contactors may fail closed and set dtcs for both contactors.battery will not be denergized and is not safe to open. No choice but to replace the $26,000 battery. Now with current failures of the dc charge contactors both may stick without setting the dtcs needed by ford to replace the battery. I’ve worked with engineering to get at least one unstuck and so far it’s worked. So hopefully ford is working on a fix for that.
Keep up the good work, looking forward to more videos!
Thanks for the kind words and the great information. Stuck shut contactors is no more dangerous than working inside the battery. Just unplug the battery positive and negative cables from modules to the junction block and the power will be removed from the junction block. I understand why Ford would take thin stance, but unless I am misunderstanding something, it is not a big deal. Personally, I cannot see how stuck shut contactors would damage anything else inside the battery.
I just want to say thanks for your work. Your early feedback as a tech is helping Ford engineering make electric cars safer for everybody.
I'm currently going through this with my dealership...I was told they are doing some sort of software "update" and not a replacement. I have the Premium AWD with extended battery, I hope I don't have this error again. Typically how long does this repair take a tech? I'm assuming dropping the battery is a 2 person job and takes hours to do...
One of the most beautiful videos in this channel indeed... thanks so much professor for all this effort to showing us this detailed components 👋😎👋😎💥💥💥💥 ill share it to my students in my classes for sure 😎🥁🥁😎🥁😎🥁🥁
Thank you very much!
If I had teachers like Professor Kelly when I was younger I would have grown up to be extremely successful.
Thank you Dave
You are a true legend! I learn so much from watching these videos. Thanks for making them available!
Thank you!
Fascinating and thorough investigation, thank you Professor Kelly for your work!
Thank you very much
Thanks for the info about the contactor #. It is a custom version of the TE Conn. (formerly AMP) of EVC500 high current relays, aka contactors. While there is no specific data sheet for this exact part number, it has the same characteristics of the two dozen or so variants, which have different mounting, coil, termination & activation specifics. These are rated for 500 A for ~ 7.5 minutes @ 85c when using rather thick copper cables (400mcm , 203mm^2) directly attached to the threaded studs. This important, since this copper wire is > 20 mm / 0.82" diameter and weighs > 1.3 pounds / foot and removes heat from the contactor. Unfortunately, this is not available in Ford's design. The 5 min. "Max power time" of the Mach-e is likely due to the 7.5 minute rating of this contactor.
Another consideration is that the coil to activate this is 22 Ohms, which means ~ 0.55 A @ 12V or > 2.2 A / 26.4 W for the 4 contactors during fast charge. With the large, quick activation force required of these solenoids (i.e. a contactor is a solenoid activating built in contacts) the rated voltage (i.e. 12V) is applied to "energize" and "pull-in" the movable core and exert the force required (i.e. close the contacts). In this case it means 0.55 A (i.e. 6W) per contactor. After the movement of the core, when the work is done, the voltage is usually reduced considerably, to < 1/3 since it takes a lot less energy to "hold" the current position. The coil of this contactor has a rated "hold" of 1.5V max. This means, that after activation, the 12V 0.55A power can be reduced to 1.5 V ~ 0.068 A ~ 100 mW or 1/60 of the power to activate it at 12V. TE Conn. offers variants of this part with built-in circuitry to accomplish this, but the chosen Ford part # does not appear to do this, relying on external circuitry. If this is not done carefully, it will definitely heat the coil and/or the contacts.
So how can Ford "fix" this with a firmware (i.e. software) upgrade? For Driving, it can reduce the maximum current drawn by the motor driver 3 phase inverters. This of course would reduce the Torque, Power, and resulting acceleration available to the wheels. For high current DC charging, Ford must rely on telling the charger to limit the charging current by reducing the charging voltage. This of course would slow down "fast charging" and increase the time required. The alternative is to replace the module with a different design to accommodate the high currents and temperatures needed to keep the existing marketing specifications. As can be seen from Dr. Kelly's videos, this could easily take a working day at a dealer. This assumes they have the equipment, trained technicians and parts readily available.
As I mentioned elsewhere here in the comment section, there are many attorneys who would love to take on a class action suit for this.
Very interesting technical information, particularly regarding the apparent failure of the systems integrator to optimise the application. Hope John spots this post.
@@paulaxford6754 You are very polite.
Thanks for the great information!
Great video demo, doing a mach e bec and took the class from ford almost 2 years ago, this helped, Thanks.
"Wow, that was a fighter"
There's always that ONE plug that fights you that extra round. :)
Great info John. TYVM Sir.
-Dave
LOL, I usually do not have that much trouble removing a connector. Thanks for watching
@@WeberAuto ⚡✌️
🤜🤛
Thanks Prof. Kelley, learning and understanding so much more by watching your videos on the Mach E!
That is awesome! Thank you
Absolutely love these videos and this topic hits home. I work for a Ford dealer and I have got to spend a good amount of time with the EV line both Lightning & Mach E. I have replaced a HV BJB on an Escape PHEV. I really enjoyed it, was a nice change of pace from the ICE side of things. Thanks for doing what you do and taking the time to share your knowledge!
Thank you very much!
Dr John it’s so easy to understand when you explained sir,but it’s very difficult to find a problem in real world thank you so much for your great work
Thank you. Understanding system operation can help with diagnostics
I can see some value in minimising the number of contacts used in any of the high-current paths. The Kona/Niro use one +/- set inside the pack and others in series for the inverter and DC charging, not to mention the lessor concerns of precharge and battery heater. There is a HV junction box for distribution, presumably something Ford saw reason to avoid in light of the added complexity of the rear drive systems. Thanks for videos, John, and I do appreciate that the dialog is confined to the technologies employed and delivered without bias.
Thank you very much!
Thanks for the thorough explanation professor I was able to support on-site commissioning of Mach-E on site during my time working at Ford, also I was able to help trouble shooting several contactors issues before mass production, fortunately, we were able to replicate ALL lessons learned across electrified programs.
Thanks for the great explanation showing the workings of the circuit. Keep it up.
Thanks for this! I learned a lot. I love my Mach-e AWD and now I know what the contactors do.
I hope the battery junction block on my car never needs repair.
Glad it helped!
Thank you Professor for your detailed exploration and explanation of this device.
You are welcome!
This is a great demonstration about working on any HV battery at this level. If you understand how a battery is constructed, and what you are removing, working on a HV system doesn't need to be scary. Respected, certainly. There is safety in understanding the internal construction and where the two polarities meet. That, and of course only using one hand.
Thanks Jake, that is absolutely true!
Never would have considered Weber University for my young sons/daughters but these videos have got me thinking.
It is a great school!
As a DYI I will probably never work on one of these, I appreciate these videos as I have some understanding as to how these cars work.
Glad you like them! Thank you
Terrific video! I have two Mustang Mach-E vehicles, including one GT Performance Edition. I feel like I understand my cars and how their electrical systems work far better after watching this video. The only other thing I would like to have seen is an explanation for the HVBJB recall, i.e., why are the main high-voltage contractors welding shut or open, and what's the fix for that?
Thank you. I do not know the exact reason for the recall. I think the recall notice said something about improperly sized contactors overheating under heavy acceleration or DC Fast charging..
Thank you for your awesome detail to this unit.
Another great informative video explanation, thank you for the information Professor Weber, much appreciated 😁😁
My pleasure, thank you
Super interesting and useful. Thanks for presenting these unique videos. Well done.
Glad you like them!
You make complex things very simpel and understandning thanks MR Kelly
Glad to hear that!
These are great videos! I went to school for automotive in 2006 and am very interested in the new technologies.
Glad you like them!
Thank you for posting your informative interesting video's
My pleasure!
Very informative as always, thanks 👍
Thank you
Very informative video thanks
Great video as usual 😎
I was expecting way more drama when the contactor moves !
Thank you!
Nice & beautiful thanks so much professor we very much appreciated it ..👍👍👍👍👍
Thank you
Thanks for another great class
Glad you enjoyed it
Amazing! Thank you
This video is amazing thank you
Glad you liked it!
Glad to see another video John, was getting a little concerned in these crazy times
Wow somehow I have missed all of the recent Uploaded videos
lol, It had been a long time. Thanks
More to come!
Sounds good. These videos, and the extremely long repair time it took to get my Hyundai ioniq hybrid repaired after an accident got me interested in all this, to hopefully, even if only in my now residing state of Indiana, reduce the repair times and speed up the adoption of these types of powertrains in the future.
I have the same Fluke adjustable leads. Expensive, but worth every penny.
Agreed! Thank for your feedback
They don't make it easy to service that module do they? I get why it is in there, but those battery packs have loads of screws just to expose the batteries. Reminds me of my service days. Just to take the lid off of a Visual Display Unit was something like 28 screws. They all required specific torque specs when putting the lid back on otherwise they would snap off or strip out. Time sinks are the worse when it comes to out of warranty work. Great videos... I'm glad I found this channel. I love watching and learning about how stuff is put together and functions.
Thanks for those videos is a very usefull information you are giving. I wonder if one day you are going to mae videos measuring voltage on a inverter side of the circuit.
Thank you.
Precharge inrush current manifests itself as a spark. It would be interesting to see just what sort of spark is produced not using precharge resistors.
Just a note on precharge resistors: in the electric bike world usually 48v or less is used.
Even at these low voltages you still get a sizeable spark when you first connect the battery to the controller ( capacitors in controller charge up very quickly). Most ebikes just ignore the problem.
The solution to this is also a precharge resistor in parallel around the main on/off switch, precharge resistor has its own on/off switch or makes contact just before the main power switch contacts.
What I find fascinating is the electric bike developed somewhat earlier than electric cars, you could argue they were the forerunner for electric cars, the systems on electric bikes are basically the same as electric cars though lower voltages and somewhat more simplistic but the principles are all the same.
Its a very interesting history that is not well known about.
Great video as always, thank you.
Is Ford replacing the contactors with the same part number or is there a new P/N?
Do new cars off the line today have more robust contactors or does it take longer to implement changes?
Good questions. I do not know the answers
Thank you!
You are welcome
Fascinating video. I would like to see the inside of the contactors, to see how it compares to an old automotive starter solenoid. The junction block just doesn't look like a mature product. I imagine there's a reason, but why is this assembly mounted inside the battery case? And even worse, why are the fuses inside? As a retired electronic tech, this looks like a maintenance headache. Also, this is just a personal annoyance, but at 20:27, on the right side of the frame, you'll see what appears to be 3 punch-down connections, for what are later identified as capacitors. These connections worked fine for phone lines once upon a time, but in the battery of an electric car, subject to vibrations, I would have liked to see these soldered as well.
Mega Awesome.
Thank you!
A lot of safety in disconnecting from the battery pack could be gained by having some "cups" made of a transparent flexible plastic (silicone?) so that the connector as an extra amount of isolation. The "thing" is that when a mechanic feels the need to disconnect some wires it's because something "popped" and there might be come contamination of surfaces which could cause leakage to have a flashover.
Thanks for the information!
Thanks for your videos. These contractors seem to be failing lots on the 2022 models. Can you talk about that sometime? Seems like it’s mostly the positive contactors?
Very good stuff. Great detail. I love that ford is making battery packs that can be diagnosed and repaired, rather than just replacing the whole expensive battery. I look forward to a peek at the battery modules. I have seen them briefly before, but in no real detail. I suspect that there will be aftermarket work-arounds for replacing contactors on the Mach E in 10 or 20 years since they are mechanical. this kind of engineering is needed for sustainability and the extrordinarly long life that EVs can hypothetically provide.
While I prefer the Volt's battery cooling scheme, Ford's single cooling plate system allows module replacement while the Chevy really does not. I would really like to know the thickness of the Ford's aluminum heat transfer plates that is between cells in the modules.
Tesla's move toward glued and sealed unrepairable batteries, gluing components together, is a strategic mistake in my opinion, making the cars themselves effectively disposable after the battery eventually fails. Tesla rejecting even the idea of 8-900V architecture is, in my view, shortsighted. the lower amperage of high voltage systems imposes far lower thermal loads on components. Tesla undermines the future value of their cars as they age out of warranty and any battery pack failure leads to a $20k repair.
Thank you Bill!
Perhaps that's why they make more Teslas in 3 weeks than all the Mach-es made to date (~100,000), have over 3 million on the road with zero recalls as opposed to the 100% recall of all Mach-e cars produced. Why is no-one asking how the GM Bolt batteries are being repaired, repurposed or recycled, since 100% of them are also recalled? As for 800V, losses are lower or allow using thinner cables, but at a large expense compared to 400V systems. Tesla chose to design their current flow efficiently instead of a bunch of orange cables and custom connectors all over the place.
@Bill Kerr Bill, I understand your argument, but keep in mind the structural battery pack is less expensive to manufacture. It is also modular and quickly replaceable. That said, I believe the 4680 cells can be electronically removed from the pack as it ages and cells die, making replacement unnecessary long past a normal "dead" battery condition. And that said, by the time the pack is due to be replaced, the cost should be down quite a bit--at least on par with replacing a tired ICE engine in a high-end vehicle. (At present, I understand Gruber motors can remove, repair, and reinstall a defective battery pack in older Model S for about $5,000. Yes, not a new $20K battery, but plenty good enough to get back decent range and utility. Think of rebuilding a tired ICE motor--about the same cost.)
@ Shazam You are perfect. Teslas are perfect. Thanks for your comments.
@@Krunch2020 As are you for acknowledging the facts I pointed out.
Very nice to delop tech
i was hoping to find out more on the recall you mentioned where the contactors were welding together. What was Ford's solution ?
It's interesting to compare this battery to the 12 plus year old imiev 16kw battery. This thing is so complicated and huge with its cooling, heating plus far heavier duty output devices. It however looks far better made and is very tidy in design. I hope these modern designs can reliably last 15+ years without attention.
Thank you Prof, nicely done. Given the field failures and recall ... any thoughts about how the HVJBB *ought* to have been designed? Or is it "just" a case of parts not meeting spec??
I don’t have enough information to answer that question. Thanks for watching
Great explanation!! Sir do you have any experience on hv connections and Stabilant 22?
I do not
Theoretically speaking, could you convert your standard range battery to extended range by simply adding the 2 upper cell banks?
@mikeselectricstuff hey, What are those capacitors called?
Thanks👏👏👏!!!
Thank you
Hi prof. do i understand correctly that the high voltage sensing lines are directly connected, via a connector, to the control box , so without any fuse or overload protection. seems to me bit unsafe as the (unlimited) DC current can flow in this small cable and cause problems when connected (cable fault or short cut some where down wards) to for instance a negative some where! just wondering.
and greetings from NL and as always interesting video
Thank you. I do not know the answer.
Professor, one query, since HV battery will have high voltage charge while Fast DC charging...then why we would need precharge circuit to be on?... I guess that what you said in the end. Request to help me out here...
Шины маленького сечения. Интересна реализация контроля тока и его регулирование при быстрой зарядке.
I wanted to see one of the contactors come out and see what was inside it.
So to replace those fuses you have to disassemble the battery. Wow.
- We fixed your car, sir. It was a blown fuse.
- Great, that shouldn't cost much, right?
- Not at all, just $5 for the parts and $5,000 labor. 😂
LOL! The fuse is just a symptom of the real problem, but yes, they are inside the battery.
Excellent video. Very early in the video you mentioned that there was a recall of the high voltage junction box, but you did not say if the unit you were working on was one on the recall list. Also, do you know if the contactors used are proprietary or mass produced? In my opinion, if they are a mass produced item they should have been made a replaceable component. If they are proprietary it would be interesting to find out why Ford engineers decided a proprietary design was needed.
I believe all Mach-Es are under recall, so that would include theirs.
The contactors are almost certainly an off-the-shelf part. That said, they probably chose not to make them individually replaceable (apart from the module they are attached to) either for manufacturing ease or to limit the number of connections to the component. Every connection is a possible point of failure, especially when you’re talking about a connection that has to deal with hundreds of kw.
Thank you! Yes, as Kevin Berg said, all Mach-Es are involved. Right now there is a software update to address the problem. I suspect it lowers the allowed current under full acceleration. The nominal rating for the fuses are 630A (Rear Motor) and 350A (Front Motor). I saw a video last night from Bjorn Nyland showing about 1050 amps on the Mach-E GT during full acceleration. I suspect the fuse sizes, contactor sizes, and maximum allowed current just needed to be better calibrated to avoid overheating the contactors (A possible reason for the five second power limit). I will be surprised if the junction block gets replaced as a result of the recall.
@@WeberAuto --Well, heating is more of a problem with the fuses. The nice thing about fuses is that they have "thermal mass" whereby the time it take to blow is a function of the current. Contactors should have problems with heat due to the load current.
@@WeberAuto Ultimately the contactor needs to be re-designed, which would preclude re-using the module as-is. The question is how much of a performance degradation and longer fast charge time Ford can "sell" to their customers. Even if it is only 5%, there are a lot of attorneys eager to cash-in a large $$$ law suit.
Thanks)
Thank you too!
What's the reason for having contractors on the negative terminals? Is it just for redundancy incase the positive contactors fail/get welded on?
You are correct, redundancy
Very very interesting
Thanks for sharing!
Just one note. For a while now several electrify america stations offer 350kW charging. Of course the car limits this...
Thank you. The 350 kW EA chargers in our area still cannot exceed 350 Amps. You cannot get close to 350 kW without using 800 volts at those stations. 800V x 350A = 280 kW.
@@WeberAuto ahh this makes sense now. Thank you for taking the time to clarify! I heard from some Mach E owners that sometimes the charger shows 156kW and then it maxes it out.
It seems like the older EA stations are limited to 350A whereas the newer installs are not. I run into the issue with my Ioniq5. Even though it runs an “800V” system (more like 700V), unless the charger outputs that voltage, the vehicle will ask for about 400V from the charging equipment and the rear motor inverter steps it up to battery voltage. It seems like the 150kw EA stations will only do 400V. This 350A limitation on the older EA stations means that my Ioniq5, which can charge nearly 240kw on a properly rated charger, will charge at around 130kw on an older 150kw EA station. The newer 150kw EA stations that aren’t limited will charge it at 150kw. First world problems, I know… It charges just fine at full speed on any of the 350kw EA chargers, but they aren’t available everywhere.
@@ouch1011 Great information! I will have to find a newer installation and photograph the product label.
I loved how you muted the video when you unplug that last connector @13:00! 😅
LOL!
That's really valuable contents. Always Thanks.
Anyway Can you share information of the glove? I need to buy one to exam. some electric exp.
Check the weber auto safety video. He explains them there
Thank you!
Dr. John, a quick question. If for whatever reason one of the main motor fuses pop, will the service tech need to drop the entire battery case or does he have access without removing the battery?
The battery must be removed to replace the fuses
I thought immediately the same, a little uneasy to change a fuse. And the whole junction box needs 8 bolts? There is a lot of assembly time needed, I think...
Thinking about it, there are sure reasons for the way they are... I could imagine a few myself, actually.
Wouldn't it be better for serviceability to relocate the junction box assembly outside of the battery cell unit? Also, how waterproof are these components? Very interesting video.
Some vehicles have an external junction box. The battery housing is sealed from moisture and dust.
Thanks for the update.
Any chance you guys will get your hands on an F150 Lightning in the coming months? Looks like they're experiencing similar HVBJB issues and would love to see the similarities in battery construction.
I hope so. From what I have seen the battery is very similar in construction, but has a higher kWh rating.
Thanks Prof. Kelley, I'd like to know more, EV Toyota BZ4X
I am wondering why there is no chill plate underneath, or venting thru the chamber, to get rid of the heat generated from pre-charge resistors, and resistance under high current warming up the bus bars.... Are there any sensors present to detect temperature, or pressure in the compartment since is is 'sealed' ?
The pre-charge resistor is only used for a fraction of a second while the capacitor charges. Not a lot of heat generated.
Nice video again, I just cannot understand why the contactor thingy is inside of tge high voltage battery. This is very difficult to replace or fix in case of any kind of failure. In my opinion the contactor board should be placed inside the car. e.g. trunk / frunk. 🇫🇮👍🇫🇮
Thanks for watching
Thanks for this very interesting insight. I wonder if the Mach-E SR RWD will also suffer a failure in the future with a higher milage, or if they are safe, especially with the software upgrade because of the lower power...
I suspect the software upgrade will eliminate the issue.
@@WeberAuto Thanks!
For Level 1 or 2 AC charging, the main contactors still need to close correct?
No, just the auxiliary contactor and the main positive contactor
I really hope there are smaller fuses downstream of that AC fuse, Very stupid to have to pull the battery if you had an issue with the AC compressor and it blew that fuse.
There are not any downstream
Why not integrate the voltage sense into the module and communicate externally via a low-voltage data bus? Why use HV for a sense signal?
I guess you are correct about all 4 contactors being on for DC charging but it does seem strange that they would run the charging current through two contactors in series. I can see that they might want to have the inverter capacitors across the battery while DC charging.
The current sensor would not be the inductive type that is for AC power only. For DC sensing, the sensor will be a Hall Effect type that uses an integrated circuit.
Thanks for the information!
There are combination Hall effect and inductive AC current sensors. Tektronix has made oscilloscope probes like that for over 50 years.
@@shazam6274 Definitely there are combination AC/DC current sensors. For this application, I am fairly sure only the Hall effect is needed.
Don't forget. This car has some V2G capability. "DC charging" is also "DC discharging". The battery is still bridged directly to the SAE Combo connectors, but instead of power flowing in it flows out.
This means that when you activate the V2G capability (in a power outage according to the commercials) the motor controllers are receiving voltage.
@@stevebollinger3463 It would make sense to use the precharge for V2X capability. A V2H or V2G box is going to have a large input capacitance and may not have a suitable inrush current limiter. Is Ford offering any V2X hardware for the Mach-E like they have for the Lightning pickup? I haven't checked with Ford but thought they would only sell someone the V2H box if they had bought a Lightning.
Nice detailed explanation and overview. Thank you. Two corrections: 1) It appears that the large white contactors are held in by two bolts on the top and two nuts on the bottom, therefore are "serviceable". 2) All of this work is a total waste of time, since Ford has announced that the warped, arced, welded contactor issues can be remedied with a simple "software upgrade"! 🤣
The issue that cause the welding is a bug in security software, so you're way off base on what the fix is for a welded contactor and what the remedy is to prevent it.
@@vidznstuff1 This is Ford's solution, not mine.
Thanks for your feedback
realistically ford isn't solving the problem with SW. What they are doing is bending the curve. If they just let things lie, they would have a large # of warranty fixes all at the same time all leaving the customers stranded. now they will have that smoothed out a bit ,over a longer period of time and with sufficient warning to allow customers to schedule fixes. It's less costly for them, and less dangerous for their customers. I believe the part itself is flawed, and can only be fixed with active cooling or a lot more metal.
Nice explaination of the junction box. What I do not understand is why the inverters need to be turned on (through the main contactors) while DC fast charging is in progress. Any idea?
FYI: In Europe we got 350kW DC CCS fast chargers. But most of them are only 200kW chargers with two balanced cables.
Thank you!. Powering the inverters during DC fast charge also powers the A/C compressor and cabin heater. Thermal management of the battery is needed while charging. Additionally, the driver of the car might want thermal management of the cabin air while charging.
@@WeberAuto Thanks, sounds resonable
Video is interesting, well done and very informative.
Is there a pyro fuse anywhere since they are used to disconnect the HVDC in the event of a crash?
No pyrofuse, just the four fuses shown in the video.
In the Tesla, it is activated anytime the Airbags deploy. Here it's just "Burn Baby, Burn"
@@shazam6274 Tesla fanboy what do you think the fuses are for?
@@danielwiggins2656 you mean like the ones in all Bolts?
@@shazam6274 I understand the bolt fires were defective batteries not from a short caused by an accident
Professor . In 48V systems which can deliver up to 280Amps , the torque of those 10mm nuts is between 4-8Nm . Assuming this is also the case in EV ???
Thanks sir, I have a question in that Current sensor on the positive side the contactor on the junction box has a coil inside that circular piece? Thanks
I believe so, but do not know for sure
@@WeberAuto thank you so much sir
Why do we need use another contactor in the negative side?
I hope future models down the road have the hvbjb outside the battery lol
Thanks for watching
Dear Professor Kelly, I was wondering if you could totally take apart an electric motorcycle ( perhaps a popular low power bottom of the range model and a more powerful one). Are they DC engines with no inverters. What sort of contractors do they have. Many people are watching your channel from Asia. In many countries eg India , 2W and 3W are more than 80% of the vehicle parc now and in the future. Thank you.
Thanks for the suggestion. It is unlikely
Those capacitors are Y caps for EMI suppression. They provide a path to shunt HV transients from the inverters or off-board charger to chassis.
Thank you very much!
Years ago a gifted older engineer I worked with pointed out that capacitors in and of themselves don't dissipate energy. The electrical component that does this is called a resister. When designers throw caps at a transient problem they are counting on the series resistance of the cap absorbing the energy. But this usually isn't a part of the specification for a cap except to having a maximum value. If designers want to "snub" transients, they need to specify the high frequency performance of the caps or just go ahead and put a discrete resistance in the circuit.
@@GilmerJohn these are Y2 caps that are specifically designed for this application. They also have self-healing properties to last the lifetime of the application. The are selected by using the reactance formula to target a specific frequency range to snub or shunt noise to ground, keeping that frequency range from getting into sensitive electronics, such as the BMS IC measuring cell voltages to an accuracy of less than 1mV. It's common practice. Even cheap toys with dc motors have these X and Y caps across the motor terminals for the same reason.
There also very specific safety requirements for isolation resistance that these caps are designed to meet. The BCM will have an isolation monitoring circuit to constantly check this.
Thanks.
I would love to see the specs/part numbers of the main contactors. Any chance you can share some details there?
They are made by TE Connectivity. Part number 2342963. I could not find a data sheet with anything other than the physical dimensions
@@WeberAuto Thanks! It looks like they list that as a EVC500L, though they have it looks like 7 variants with different length/colors of wires. Their EVC500 (no L) looks to be rated for 500A continuous. So that might be too low of a rating for running maximum power through for long which is likely ~900A.
@@mp3mike237 Is Ford replacing the contactors with the same part number or is there a new P/N? Do new cars off the line have a more robust contactors or does it take longer to implement changes?
Awesome and thanks for doing this. I am still not clear of the exact circuit and contact sequence for the 12V power supply to come on when not under power? DC to DC converter when the main power is not required (12 V maintenance while parked). The black box contact TE 2203997-1 is the negative contact and the negative main is bypassed to take the inverters out of the loop? Does the pre-charge contact come on before the main positive closes in this case? If the main negative is bypassed but the main positive closes does the pre-charged positive come on first or since there are no capacitors no arcing of the main will happen? Is the sequence TE 2203997-1 contact negative and then main positive closes?
This sequence I think would maintain the 12V when parked but does not some times. Mine gets a P00A2 positive contact stuck open error in subfreezing (-30C) and the 12V is not maintained. Then at a certain soc the 12V proceeds to freeze/die. At that point nothing works well and a 12V charger is required to thaw it out and charge it. Wonder if I am right in assuming the P00A2 is the main contact stuck?
Thank you, yes the black contactor bypasses the main negative contactor and precharge is not needed. I think you meant P0AA2 Hybrid/EV Battery Positive Contactor 'A' Stuck Open. It sets if the BECM detects the contactor is stuck open for 2.4 seconds. A stuck open contactor will prevent the DC-DC converter from charging your 12V battery.
@@WeberAuto Thanks again valuable info. So the dc/dc not getting power would be limited to the main + and the black box contact? Pre-charge not involved. When I put the car in accessory mode (no brake) is it running through the black box?
@@peterpan8727 I believe that is correct
@@WeberAuto Thanks again. Sounds like a definite maybe? Not a for sure but would make sense. LV sensors in the HVJB case before you put it back in for the 9th time 😉? It all happens over 12V (off and on contacts) so if the 12V is dead not much happens.
2 new 12V 2 times dead in -28C so maybe not the 12V? I think it does not keep the 12V at a high enough soc in the cold either. That is pure software logic. Such a big battery should be able to keep the 12V charged. Stuck open positive and get in with a car with a low (dead) 12V and will not clean boot or go in gear. Happens fast day, day and a half. Summer it sits for 2 weeks not a problem. Charge the 12V and the car powers up and runs fine. Keep the 12V on charger/maintainer in the cold no problem either. Does not maintain itself and I was not the only one up north last winter but I was the first winter. Two winters both times not fixed until April when it is not a problem anymore. Last time they replaced the HVJB and BECM and now waiting to see if it is fixed. The recall got me thinking about this again but I do not think they are welded shut in -28C it say positive stuck open.
The pre-charge can not be totally ruled out for the dc to dc to power on and may be does need to happen. Really still do not completely understand the accessory black box negative (hvac dc to dc and ac charging) do they always get their power through the black box negative even when powered on and the main negative is closed? Always two feed from the HVB one running through main negative and one through the black box one?
BTW, these contactors seems small vs what I seen on other cars like Tesla, Hyundai and so on.
Are they under-rated ?
I do not know
Is there no fuse in the high voltage sens line.
I see the problem if the fuse blows, however a lot of power through a small wire.
Why didn't they use auxiliary function on the relay.
As usual a good video.👍
Thank you
Effectively, the operative assumption is that the wire will act like a fuse. I hope the designed test this.
Hi John, thanks for your excellent videos and your sharing of deep engineering knowledge. I ordered last year the European Mach-E GT (= US performance Edition) which hasn’t been delivered yet. I don’t understand why Ford has difficulties with the HV junction box or thermal issues and other car companies like Tesla not. What does the competition make different to manage high currents in their high performance cars? Why don’t they need time based limitations. Greetings from Germany, Thomas
Because of better design: Not having lots of thick, expensive wires with custom connectors all over the car and over 30 custom hoses in a hose rats' nest. FYI: The Tesla "Plaid" cars have over 3x the current requirements. Your wait maybe due to the fact that Ford is losing money on each- car and doesn't expect to "fix" that for several years until their new factory for electric cars is built and ramped up.
@shazam. Bullshit. It was a software bug in the security part of the software, not a hardware issue. This car will make your Tesla shares worthless so get used to Tesla's continued loss of market share - none of your cheerleading or FUD bashing makes any difference.
@@vidznstuff1 🤣🤣
Thank you, I do not know the answer.
More mass -- I would guess the equivalent part for tesla has either more mass or active cooling. My understanding is the replacement part is beefier, but there are limits to how much they can add due to space constraints. I would be very curious what the equivalent part in the F150 lightening looks like
What areas of work on these new gen EVs require PPE, and how does that ratchet up the level of difficulty completing servicing tasks?
Each EV manufacturer has their own recommendations for when to use PPE. There are laws, standards, and regulations related to high voltage on vehicles. Some EV manufacturers cover almost every possible high voltage connection reducing the need for PPE. The level of difficulty is not necessarily higher, but it is newer and there are many things for service technicians to learn.
Thank you for such an excellent video. GT Owner here and was just curious about recall. Having followed the recall commentary elsewhere there is talk that the software mitigation somehow can sense an "about to" weld contactor through some electrical property change due to deformation of the contactor. Would you have a suggestion on how that might work? (I don't have a background in electrical engineering so forgive me if I am talking rubbish!)
They hope to reduce maximum current available in operation and charging (i.e. less performance, longer charge times). They ultimately have to re-design those contactors and replace the entire module, which as you can see from this and the previous video would take the better part of a day $$$. Even after re-design, these are custom parts and would take quite some time to get from their vendor.
@shazam More bullshitting. It was a software bug that is being fixed by update.
@@shazam6274 Tesla fanboy the software did not reduce the maximum current available in operation and charging.
Since Ford has not "released" this fix, how would it protect the contactor from arcing, warping and overheating??
I do not know the answer to that. I suspect they are watching the voltage drop across the contactor while it is being used. A perfect connection would have a near zero volt drop. A contactor that is starting to develop problems may have a higher voltage drop. Thank you!
I wonder how many people get zapped from not using proper precautions. I have been zapped by 220v a few times,really wakes you up,lol
and like guns for combat being supplied by the low bidder on the contract....this unit looks like it suffers from the same thing. thaks for the peek. :-)
Thanks for watching
Q,The low voltage control wires ,that effectively turn on and off the high voltage battery ,look rather small for the important job that they do ?. considering that they are the only way to isolate the High voltage Battery,what happens when there is an issue with those control wires and their connections?
Anything is possible in automotive ?
When the conditions of Fire ,water or accident intrusion, there could be a problem !
There is no manual override is there ?
Rust belt locations in America,would they be a threat to these EVs ?
The wires are sized for the amount of current they carry, which is very small. If there is a failure of the wire, which is unlikely, the contactors would open/turn off and disconnect the battery.
If you’re concerned that the car could be disabled by damage to the wire, that’s true for literally any car with any powertrain. Any gas engine could be disabled by removing power or ground on a single wire.
@@ouch1011 thanks,the issue would surely be the 450odd volts ?
Also Fords have had issues weird occurrences with the vehicle systems and something to do with faulty batteries be the communication that they have for updates which are wireless,it maybe sorted !
I just think the batteries can be a bigger issue than what ICE cars are .
If there is an issue with the control wires resulting in abnormal contactor operation, diagnostic trouble codes (DTCs) should set. The results of a DTC setting vary by system, but the vehicle is usually disabled after stopping and turning off the car. There is a battery contactor recall for this issue right now.
How many Mach E have actually had this problem. I have 28000+ on mine and have had no issues. I did get at OTA about 2 weeks ago addressing a software fix regarding this. And I wonder if using 150 Kw chargers at electrify America is safer for the Mach E battery rather that using the 350kw charger. I have used the 350 kw charger when the 150 was unavailable.
The vehicle decides how much current to receive while charging. It does not matter if you pick the 150 kW or the 350 kW, it will still charge at the same rate.
@@WeberAuto You will see a higher charging rate on a 350 kW DCFC than a 150kW, briefly. Probably because as you noted the 150 don't support the necessary amps to provide 150 kW to the car.
Wonder what is the gauge of the HV wires? Wonder how hot they get during DC fast charging?
At full power there would be over a 1000A flowing through those cables. They don’t seem adequate. Is this reason for the recall/update?
There is a temperature sensor in the charge port receptacle. I do not know the answer.
@@WeberAuto
The charge port may have a sensor but there are lots of small wires with lots of connections after that. When there's large delta T and many thermal cycles the connections get loser therefore developing higher resistance causing more heat.
Would be interesting to get a low voltage high current power supply and put real world amps through the wiring and use an IR camera to find the hot spots.
i'd think putting many mechanical contractors in a very hard to access place is not a good idea. I guess ford's learning this now...