How do the dual OBCs work?

[VTbuckeye]

I was bummed when I found out that dual charger did not mean a j1772 plug on each fender. It would have been awesome to plug in to two 30amp EVSEs and charge at 60amp. I got over it a little over 3 years ago.

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[Aminorjourney]

If it's anything like the dual on-board chargers I'm fitting to my 2006 Vectrix VX-1, one will be the primary and one will be the slave.

(Bear in mind I'm talking about fitting dual 3.3 kW chargers for a massive 6.6 kW LOL - that said, my bike came with a heady 1.2 kW on board charger lol)

 

[tls]

They kind of have to because they need to be at the same voltage or a calculated, precise offset. The easiest way to do this is to have one control the other.

 

[chl]

I read somewhere that the SR and Flash have one 11.3kW(?) charger, while the ER has two 9.6kW chargers (for a total of 19.2kw).

All Lightnings have 9 battery modules and the 9 modules all take up the same physical space in the truck.

The configuration chart for the respective batteries:

They are laid out like this:

This video shows where the SR 11kW charger is located under the floor of the frunk, as well as the DC-DC converter and other things (wiring, etc.):

 

[chl]

PS: the video also mentions that while charging the HV battery, the 12V battery gets charged by the DC-DC converter, as well as while driving.

 

[TaxmanHog]

I recall old discussion that our ER's might have two 40 amp units, but it wasn't fully proven as a fact.

From a manufacturing standardization, I'd suspect the front unit under the frunk is [48 amps @ 240 volts for a theoretical output of 11.6 KW] across the board and the unit at the rear of the truck is [32 amps 7.6 KW] found on 2022 & 2023 ER trucks with dual on board chargers.

 

[chl]

I have seen both 11.3kw and 11.6kw for the SR charger.

A Ford video said 11.3kW - it was talking about the 2024 Lightning Pro as I recall, and about the extended range battery it referred to dual 19.2kW chargers, but I'm sure that meant the total of the two was 19.2kW - previous info I saw or read referred to two 9.6kW chargers in the ER model Lightning.

Yes 11.3kW with 240V would be 47.08A, not 48A but sometimes companies round things off and prefer even numbers. At 48A you'd expect 11.52kW, which I saw somewhere rounded off to 11.6kW.

So it is hard to know for sure the exact numbers.

With losses the effective rate of energy transfer is probably around 90% of the perfect lossless ideal number, I see about 87% to 90% of the energy used is added to my battery most of the time based on the numbers the FCSP and FordPass gives me anyway. I'm sure FordPass rounds the kW added to the battery and percentages off. up or down.

This is the link to the walk around of the 2024 Lightning Pro than mentions the 11.3kW and 19.2kW numbers:



A lot of different things probably went into choosing those chargers, and not using the same chargers for all models - cost, efficiency, heat generation/cooling requirements, availability, and the length of time owners would need to have the vehicles on an EVSE at the various current levels available with Ford branded EVSE's among other things.

Go figure as they say!

 

[TaxmanHog]

@Ford Motor Company any additional feedback from engineering?

From your earlier post, I'd guess all trucks have a 48 amp front board charge controller [OBCC]

Do all Lightnings have a front OBCC that is rated at 48 amps regardless of SR/ER pack sizes for all model years 2022 to present?

Do all Lightnings equipped with dual on board chargers, have a rear unit rated at 32 amps, or do these trucks get something completely different ie. 40 front 40 rear?

 

[Ford Motor Company]

@Ford Motor Company any additional feedback from engineering?

From your earlier post, I'd guess all trucks have a 48 amp front board charge controller [OBCC]

Do all Lightnings have a front OBCC that is rated at 48 amps regardless of SR/ER pack sizes for all model years 2022 to present?

Do all Lightnings equipped with dual on board chargers, have a rear unit rated at 32 amps, or do these trucks get something completely different ie. 40 front 40 rear?

Followed up with them. I'm not *quite* as technical as y'all (I'm getting there) but hoping I can find more on this.

 

[djwildstar]

I have seen both 11.3kw and 11.6kw for the SR charger.

At one time, Ford's website had Tech Specs documents for the 2022, 2023, and 2024 model years. I have all three versions archived on my PC, but I can only find the 2022 version on Ford's site. If the others are still available, they didn't appear in the results of my quick Google search.

According to all three documents, the SR Lightning has 48A on-board charging that accepts a maximum input power of 11.3kW and outputs 10.5kW to the battery (about 92.9% charging efficiency). The 11.3kW specification would be 48A at 235V. It is likely that this specification accounts for voltage drop across a typical EV charging cable: the maximum allowed voltage drop is about 7V, and 48A x 233V = 11.184kW, which rounds to 11.2kW.

According to the 2022-2023 documents, the ER Lightning has 80A on-board charging, with a maximum input power of 19.2kW and output of 17.6kW (about 91.7% efficency). The 2024 document lists this as "Fleet Only" and does not specify Level 2 charging for non-Fleet ER trucks.

The 2024 and 2025 Order Guides specify "Level 2 peak charging rate of 11.5kW" for the non-fleet ER trims. This would be 48A at 240V rounded to the nearest 0.1kW. The Order Guides don't specify a charging rate for SR trucks, so it isn't clear if the SR charger is actually different, or if the Order Guide and Tech Specs are giving different numbers for the same charger based on slightly different assumptions.

I normally tell people that SR trucks have a single 11.2kW charger, 2022-2023 ER trucks have dual chargers for 19.2kW total, and 2024-2025 trucks have a single 11.5kW charger. This may or may not be completely accurate, but does align with the documents I've seen from Ford.

 

[TaxmanHog]

The prevailing voltage value is likely the cause for variations in statistics cited year to year.

 

[chl]

At one time, Ford's website had Tech Specs documents for the 2022, 2023, and 2024 model years. I have all three versions archived on my PC, but I can only find the 2022 version on Ford's site. If the others are still available, they didn't appear in the results of my quick Google search.

According to all three documents, the SR Lightning has 48A on-board charging that accepts a maximum input power of 11.3kW and outputs 10.5kW to the battery (about 92.9% charging efficiency). The 11.3kW specification would be 48A at 235V. It is likely that this specification accounts for voltage drop across a typical EV charging cable: the maximum allowed voltage drop is about 7V, and 48A x 233V = 11.184kW, which rounds to 11.2kW.

According to the 2022-2023 documents, the ER Lightning has 80A on-board charging, with a maximum input power of 19.2kW and output of 17.6kW (about 91.7% efficency). The 2024 document lists this as "Fleet Only" and does not specify Level 2 charging for non-Fleet ER trucks.

The 2024 and 2025 Order Guides specify "Level 2 peak charging rate of 11.5kW" for the non-fleet ER trims. This would be 48A at 240V rounded to the nearest 0.1kW. The Order Guides don't specify a charging rate for SR trucks, so it isn't clear if the SR charger is actually different, or if the Order Guide and Tech Specs are giving different numbers for the same charger based on slightly different assumptions.

I normally tell people that SR trucks have a single 11.2kW charger, 2022-2023 ER trucks have dual chargers for 19.2kW total, and 2024-2025 trucks have a single 11.5kW charger. This may or may not be completely accurate, but does align with the documents I've seen from Ford.

Good info. - I only have the 2022 tech spec sheet as well, downloaded in 2024 right after I bought my 2023 Pro - I think I would have downloaded the others if they had been there. I do have one that does not have the heading "2022" in it, but it seems identical to the one that does say "2022."

There tends to be "ball-park" numbers in engineering sometimes, esp. when the small variations don't make much difference, there is always some degree of tolerance for voltage drops, nominal supply voltage variations, etc.

Sometimes even the manufacturers specs will vary from doc to doc as well. Or the docs will be out of date on the day they are printed.

Anyway, ball park is good enough in most cases.

Now I have to go back and look to see what the OP's purpose for asking was and see if we all answered the question adequately? Hope so.

 

[chl]

Back to the question definitively about out how the dual charger set up works with the ER battery modules which was the OP's question.

It seems that with 2 identical 9.6kW chargers (40A x 240V each), and since the set up is such that the second charger kicks in for higher amperage (higher than 40A probably), and since the ER battery pack can charge at up to 80A, then it seems to me that the two charger currents are added together, in other words, they are in a parallel configuration to each provide up to a max of 40A + 40A.

The control (BCCMs) for the two chargers, primary and secondary, is such that the primary controls the secondary BCCM "...that facilitates and provides additional charging capacity for the high voltage battery when an high output level 2 EVSE is utilized... " per the Ford documentation cited above.

So it sounds to me like up to 9.6kW (40A at 240V) only the primary is operational and then, as bmwhitetx said, the second one kicks in when the current capability exceeds some level - and I'd guess that is likely the 40A threshold to provide up to 80A.

In the process, the input AC 240V is converted to DC 400V (maybe a tad higher) to charge the battery modules.

For DC charging we know the Lightning can go up to 500A (with the software tweak, used to be 450A). 500A at 400V is 200kW.

Of course that is way more than possible via L2 AC charging - 80A x 240V = 19.2kW.

So a perfect (lossless) on-board charger providing 19.2kW at 400VDC would produce a DC current of 48ADC to the battery modules.

So DC fast charging is more than 10 times faster 200kW/19.2kW (or using the currents, 500A/48A).

For what it's worth...lol

 

[Randall Stephens]

Chasing a 100% accurate answer, but the documentation on the charger system suggests the second charger is only used when input current is above 48A.

What I want to know is if in the future my truck gets totaled and I have to buy a new one, if I simply bolt in the 2nd charger or if you guys have locked the thing down so much I’m screwed. Thanks Brian, not AI.

 

[chl]

Then the question becomes why doesn't Ford use dual 40A chargers? Wouldn't that have been cheaper?

From what I have read they do have two identical 40Ax240V=9.6kW chargers for the ER battery model for a total of 19.2kW rate of energy transfer (240V x 80A) ideaally - always some losses of course.

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