Hight Voltage Battery overheating during charging on L2 after OTA

[MellowJohnny]

I guess the question is should we all be testing after receiving 6.6.0? And if so, what's the procedure?

I don't think I'm seeing the issue, but I charge on 32A L2.

Ignorance is bliss, unless my electricity bill is silently increasing....

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[ZedThou]

I guess the question is should we all be testing after receiving 6.6.0? And if so, what's the procedure?

I don't think I'm seeing the issue, but I charge on 32A L2.

Ignorance is bliss, unless my electricity bill is silently increasing....

On my MME, while beginning to charge on 7 kW L2, one can watch all of the charger energy (and then some) going into the HVB heater until the HVB temperature hits around 52 °F, and which point the EV Battery Power goes negative and it begins receiving the energy. On L1, most of the energy required to heat the HVB comes from the HVB itself, cannibalizing its stored energy.

 

[Shayne]

I guess the question is should we all be testing after receiving 6.6.0? And if so, what's the procedure?

I don't think I'm seeing the issue, but I charge on 32A L2.

Ignorance is bliss, unless my electricity bill is silently increasing....

The derating only happens when charging over 32 amp. You would not know you have the problem even if you do. If it is heating the batteries continuously you should hear the recirc pump going non-stop. That is the one that is sucking the hydro. My pump never comes on when sitting beside my igloo. I guess if we had to pick it would be derating instead of burning up the HVB but it would be nice if both get fixed.

 

[mkhuffman]

So then that means everyone is having this issue? If it’s 6.6 then I believe most everyone here has that update. Believe my latest was 6.7.

If this is really true, then of all the issues with this car, this one pisses me off the most. Why? Because it is nearly tripling my electric bill. It’s insane. A software bug that is racking up kWh on the electric bill…I’d rather pay a subscription for heated seats because at least I know what I’m getting!

Ford needs to fucking fix this.

I tested my car and I don't have the problem.

 

[Stang68]

I tested my car and I don't have the problem.

How would one test the car without any special equipment?

 

[mkhuffman]

How would one test the car without any special equipment?

Use an OBDII scanner to read the charging power going into the car and the power going to the heater. I was told it had to be below 50 degrees for the heater to come on to heat the battery, so I parked the car outside overnight and did a test L1 charge in the morning. It worked fine.

It just means not everyone is impacted. It doesn't make it any better for those who are, except that maybe you can get special attention from Ford’s engineers.

Read back a few posts and it may shed some light for you.

 

[sid234]

Just got my power bill for December

Also took my MME to the dealer today based on request from Ford, but it turns out t Ford Engineer never got back to my dealer about coming down to fix my cat after asking them to have me bring my car in for them to fix. Sounds like dealer had to call them and give instructions for a fix over the phone.

Dealer tried to fix the car via updates but it wasn't going through- going to try again tomorrow. Hoping that it works tomorrow

Got a Bronco Sport as loaner, its a decent drive, esp in the snow - tempted to just say F* it and trade the Mach E in for an ICE SUV.

 

[Mach-Lee]

On my MME, while beginning to charge on 7 kW L2, one can watch all of the charger energy (and then some) going into the HVB heater until the HVB temperature hits around 52 °F, and which point the EV Battery Power goes negative and it begins receiving the energy. On L1, most of the energy required to heat the HVB comes from the HVB itself, cannibalizing its stored energy.

I would say that's normal behavior. If the battery is cold it will want to heat up to 40-50ºF when charging starts.

The people with this issue are seeing it heat up all the way to 95ºF (excessive).

 

[ZedThou]

I would say that's normal behavior. If the battery is cold it will want to heat up to 40-50ºF when charging starts.

The people with this issue are seeing it heat up all the way to 95ºF (excessive).

Yes, this thread has merged two different issues, as far as I can tell. The battery cannibalizing itself on L1 charging is one of them. That wasn't happening last winter (again, as far as I can tell), and some of us who are mostly dependent on L1 charging are seeing our electrical consumption and energy bills skyrocket as a result.

 

[Mach-Lee]

Yes, this thread has merged two different issues, as far as I can tell. The battery cannibalizing itself on L1 charging is one of them. That wasn't happening last winter (again, as far as I can tell), and some of us who are mostly dependent on L1 charging are seeing our electrical consumption and energy bills skyrocket as a result.

Ah. Perhaps someone should make a separate topic for heating/energy issues with Level 1 charging since this topic is about Level 2 charging?

Last year the strategy allowed charging of a frozen battery (<32ºF) without heating, which is bad because it can cause cell degradation (lithium plating risk). This year, Ford fixed that so the battery is kept above freezing during charging, which is proper practice for charging lithium batteries. The change to heating before charging is why you are seeing increased energy consumption.

Personally I think Ford should use a lower battery temp setpoint for Level 1 charging to reduce energy use, such as 38ºF instead of 50ºF. The pack does need to be heated above freezing for charging, it's just a question of how much. I'm not sure if heating to 50ºF on Level 1 is a bug or desired behavior because that's much higher than what I've seen previously. Also LFP packs are more sensitive to cold and may be kept at warmer temps than NCM packs.

 

[woody]

OBDII scanner would fall under the special equipment label for many.

 

[ZedThou]

Ah. Perhaps someone should make a separate topic for heating/energy issues with Level 1 charging since this topic is about Level 2 charging?

Last year the strategy allowed charging of a frozen battery (<32ºF) without heating, which is bad because it can cause cell degradation (lithium plating risk). This year, Ford fixed that so the battery is kept above freezing during charging, which is proper practice for charging lithium batteries. The change to heating before charging is why you are seeing increased energy consumption.

Personally I think Ford should use a lower battery temp setpoint for Level 1 charging to reduce energy use, such as 38ºF instead of 50ºF. The pack does need to be heated above freezing for charging, it's just a question of how much. I'm not sure if heating to 50ºF on Level 1 is a bug or desired behavior because that's much higher than what I've seen previously. Also LFP packs are more sensitive to cold and may be kept at warmer temps than NCM packs.

Thank you, your reply gives some insight into the motivation of the change in battery heating strategy on L1.

 

[Shayne]

I would say that's normal behavior. If the battery is cold it will want to heat up to 40-50ºF when charging starts.

The people with this issue are seeing it heat up all the way to 95ºF (excessive).

Trying to get them to 35C in -10C is going to take some juice. The new transfer function reads some too hot and some too cold. Then some are in between and are partially effected one way or the other and some not at all. I would assume there are a lot that are effected but not noticed. We have the compete scale. Appears the transfer function does not work all that well or it is bringing to the surface a lot of defective hardware. I guess prior to the new transfer function it monitored nothing and the port could melt and burn.

 

[MellowJohnny]

The derating only happens when charging over 32 amp. You would not know you have the problem even if you do. If it is heating the batteries continuously you should hear the recirc pump going non-stop. That is the one that is sucking the hydro. My pump never comes on when sitting beside my igloo. I guess if we had to pick it would be derating instead of burning up the HVB but it would be nice if both get fixed.

I'm having (what I think is) a different issue - if I set my EVSE to 40A I get a charge fault. No de-rating, it ramps to around 8.5 / 9.0-ish kW @ 35A and fails. Which sounds different than this. I can sometimes charge at 34A but not always. Previous to November it charged without issue at 40A for the last 6 months.

Took it Ford and they said it was related to the derating "fix" to prevent overheating. I disagree.

 

[Homer007]

I'm pretty sure I have both problems being discussed here. I L1 charge at work and will lose about 3% of charge before it starts to go back up. On a 9 hour shift I would gain about 10% of battery on L1, but now I'm lucky to get a 3% increase (Show up with 85% battery, see it drop to 82% the first few hours I'm there, then finally get to around 88% before I leave).

I level 2 charge at home (40 amps) but noticed dips in charging. Lowered it to 34A and that seemed to help, but it's still concerning considering it worked fine prior to these last round of OTA's. (Sigh). I have the ability to update using FDRS and may have to go that route if I can confirm there's a fix anywhere.

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