High Voltage Battery Junction Box (HVBJB) Replacement Recall for recall HVBJB in 30,013 Mach-E

[Shayne]

Wow is right. Only 3800 miles in 2 years is why your LV battery is dead. Your car needs to be used for it to maintain your battery. I had 3800 miles on mine in 3.5 months.

Or smart enough to power up and maintain itself. It does not need to spin an alternator to do that and it has the power to trickle charge a small 12V battery. I see no reason to have to drive it around to charge a 12V for OTA success or just for maintenance of the 12V. We have a smart car right? When the car is working right it should maintain itself. I think it is getting better in that department?

Sponsored

 

[mkhuffman]

Or smart enough to power up and maintain itself. It does not need to spin an alternator to do that and it has the power to trickle charge a small 12V battery. I see no reason to have to drive it around to charge a 12V for OTA success or just for maintenance of the 12V. We have a smart car right? When the car is working right it should maintain itself. I think it is getting better in that department?

If you had to choose, would you rather replace your LVB every two years, or would you like your HVB to lose 2-8% every 24 hours due to vampire drain? I know what I would choose.

 

[Shayne]

If you had to choose, would you rather replace your LVB every two years, or would you like your HVB to lose 2-8% every 24 hours due to vampire drain? I know what I would choose.

The latter of course. Especially when plugged to L2

 

[mkhuffman]

The latter of course. Especially when plugged to L2

5% of a 91 kWh battery is 4.5 kWh. You want your car to consume 23 kW of power just sitting in an airport parking lot for 5 days doing nothing while you travel? That's a lot of energy for no good reason. I would hate that. And I would hate parking my car with 50% charge at the airport and worrying that I won't be able to drive it when I get back because the HVB is dead, or too low to make it home.

I would MUCH rather replace the LVB every two years. Without a doubt.

The reason I mention this is because Rivian is experiencing just this problem. Pick your poison. I pick zero vampire drain.

With current BMS systems it is not possible to trickle charge the LVB from the HVB without causing serious HVB vampire drain. All the systems that need to run to use the HVB drain a lot of energy over time. While I am sure there is room for improvement regarding how the MME maintains the LVB, it is definitely better than the alternative.

When I parked my car on Monday the LVB was around 45% SoC. When I get back to the car on Sunday, we will see how well the battery was maintained. If it is dead, then the car failed to maintain it. If it is alive, then there is no need to worry. I am pretty sure it will be alive. I'll let you know on Sunday!

 

[21st Century Pony]

Some time ago, I used a Noco small, foot-square removable PV panel on the dash for longer unattended stays (airport etc.) with my 2015 Ford Fusion PHEV. The Noco PV panel plugged right into the OBDII port and sat on the dash. The trickle-charge unattended system worked well for years.

Unfortunately for the discussion here, that really useful Noco product is no longer sold.

 

[Shayne]

5% of a 91 kWh battery is 4.5 kWh. You want your car to consume 23 kW of power just sitting in an airport parking lot for 5 days doing nothing while you travel? That's a lot of energy for no good reason. I would hate that. And I would hate parking my car with 50% charge at the airport and worrying that I won't be able to drive it when I get back because the HVB is dead, or too low to make it home.

I would MUCH rather replace the LVB every two years. Without a doubt.

The reason I mention this is because Rivian is experiencing just this problem. Pick your poison. I pick zero vampire drain.

With current BMS systems it is not possible to trickle charge the LVB from the HVB without causing serious HVB vampire drain. All the systems that need to run to use the HVB drain a lot of energy over time. While I am sure there is room for improvement regarding how the MME maintains the LVB, it is definitely better than the alternative.

When I parked my car on Monday the LVB was around 45% SoC. When I get back to the car on Sunday, we will see how well the battery was maintained. If it is dead, then the car failed to maintain it. If it is alive, then there is no need to worry. I am pretty sure it will be alive. I'll let you know on Sunday!

Sounds good. Since I reset the 12V battery learned values it has behaved much better here sitting above 80% now for awhile since and no more 40's yet. Sits for weeks and at 88% right now.

I am not sure about Rivian I bought my own problems I do not think it should take huge amounts of power to trickle charge a 12V battery. The 12V battery in the MME is FoMoCo BHAGM-H3 (35 amp/hr) 0.42 Wh and should be something that the 100 KWh battery can handle especially when the vehicle is plugged into a 240V feed.

 

[21st Century Pony]

Got my Mach E back today. 1.5 days'work in my dealership, and it included a Ford loaner car. Parts were ordered back in mid-December.

The friendly cashier (processed the paperwork, no charges to me) mentioned that she hears across the dealers' network that for this recall, the recall parts stampede and the resulting parts (un)availability are anecdotally already becoming a part of this movie.

 

[mkhuffman]

Sounds good. Since I reset the 12V battery learned values it has behaved much better here sitting above 80% now for awhile since and no more 40's yet. Sits for weeks and at 88% right now.

You reset the LVB BMS because you were getting LVB errors? If your LVB fails early, that might be a significant contributing factor. Personally, I would never do that after reading what Lee posted about the consequences.

 

[Shayne]

You reset the LVB BMS because you were getting LVB errors? If your LVB fails early, that might be a significant contributing factor. Personally, I would never do that after reading what Lee posted about the consequences.

No errors with regard to the car providing them. I was trying to recondition the 12V and the charger kept erroring out at around 80%. I reset the car and then it charged to 100% on the charger and the car. Since then the car has been keeping the 12V at a much higher SOC. It is always closer to 80 90 now not the 45 to 50% that it was before.

If this second 12V fails it would be due to the MME BMS as I do not think the HVBJB is killing this second one. I do not worry about resetting the 12V just like I do not worry about resetting the engine oil life. If it was a real problem it would not be there.

 

[ChasingCoral]

5% of a 91 kWh battery is 4.5 kWh. You want your car to consume 23 kW of power just sitting in an airport parking lot for 5 days doing nothing while you travel? That's a lot of energy for no good reason. I would hate that. And I would hate parking my car with 50% charge at the airport and worrying that I won't be able to drive it when I get back because the HVB is dead, or too low to make it home.

I would MUCH rather replace the LVB every two years. Without a doubt.

The reason I mention this is because Rivian is experiencing just this problem. Pick your poison. I pick zero vampire drain.

Vampire drain is a big issue for Teslas too.

 

[RickMachE]

To me, the design of the 12v battery system is flawed. With our PHEV Fusion, we were under the understanding that after completing charging the HVB, it would kick into 12v battery charging mode.

There is ZERO REASON that the Mach-E, and Lightning, don't charge the 12v battery to "full" (whatever full should be considered) before ending the charging session. Irrelevant if it charges while the HVB is charging. If the HVB has reached its target, then the programming should say "complete charging of the 12v battery (however that happens is irrelevant to the customer).

This is just poor design IMO.

And yes, if that meant it charged to 90% (my target), then dropped to 87% while charging the 12v, then charged to 90%, that would be fine with me. Just provide messaging (HA!) telling me that.

Like the messaging that says "Preparing for Drive" when it fact it should say "I'm warming the HVB you dummy".

 

[Shayne]

To me, the design of the 12v battery system is flawed. With our PHEV Fusion, we were under the understanding that after completing charging the HVB, it would kick into 12v battery charging mode.

There is ZERO REASON that the Mach-E, and Lightning, don't charge the 12v battery to "full" (whatever full should be considered) before ending the charging session. Irrelevant if it charges while the HVB is charging. If the HVB has reached its target, then the programming should say "complete charging of the 12v battery (however that happens is irrelevant to the customer).

This is just poor design IMO.

And yes, if that meant it charged to 90% (my target), then dropped to 87% while charging the 12v, then charged to 90%, that would be fine with me. Just provide messaging (HA!) telling me that.

Like the messaging that says "Preparing for Drive" when it fact it should say "I'm warming the HVB you dummy".

Just a small 35 Ah battery and the car should be smart enough to manage it. Mine sits around a lot but as of today (below) it is still working well after the relearn/recondition. I think that 15 to 20 minutes auto preconditioning in the cold may help? Let it sleep and don't play with the app to wake it up helps that vampire drain a bit also I think.

 

[Ottuso]

Mine (2021 premium ER AWD) never failed, but it was recently replaced.

 

[mkhuffman]

I finally scheduled mine. Still no failure after 2+ years of daily WOTs.

The dealer confirmed they received the new part, not the reman part. It took them about two days to get the part, so it is strange others are taking so much longer.

They said it will take two days to do the replacement and they will be giving me a loaner car along with Ford points.

This is proof Ford knows how to do it right. And my local dealer is one of the good ones. They have always been great, actually.

I am MUCH more likely to buy another Ford because of how they are handling this recall. I know it took a long time to get here, but I am very impressed.

Sponsored