Recommended 12V Battery SOC to Receive Updates?

[Jimrpa]

What is the recommended 12V battery SOC to receive updates? My 12V battery SOC seems to be around 60% - 65%. I went on a “charge the 12V battery drive” to get the SOC to 70%. When I went into Starbucks for 5 minutes, the SOC dropped to 68%, but I was able to get it back to 71% before pulling in my garage?
Related question: if I leave the car “running” in my garage, AND plug in my L2 charger (FCCS), will that fully charge the 12V battery AND keep the HVB charged?

Sponsored

 

[YunniorO]

What is the recommended 12V battery SOC to receive updates? My 12V battery SOC seems to be around 60% - 65%. I went on a “charge the 12V battery drive” to get the SOC to 70%. When I went into Starbucks for 5 minutes, the SOC dropped to 68%, but I was able to get it back to 71% before pulling in my garage?
Related question: if I leave the car “running” in my garage, AND plug in my L2 charger (FCCS), will that fully charge the 12V battery AND keep the HVB charged?

Most OTAs require the 12V battery to be above 75% SoC (state-of-charge), and sometimes up to 95%.

https://www.macheforum.com/how-to-get-failed-otas-to-install/

 

[Mach-Lee]

What is the recommended 12V battery SOC to receive updates? My 12V battery SOC seems to be around 60% - 65%. I went on a “charge the 12V battery drive” to get the SOC to 70%. When I went into Starbucks for 5 minutes, the SOC dropped to 68%, but I was able to get it back to 71% before pulling in my garage?

It depends on the update, some require more than others. 6.6.0 and 6.8.0 require higher 12V levels. I would recommend 80% or higher to get those to install. In some cases 80% may not be enough if your battery capacity is degraded. The actual threshold % is dependent on battery aging and is not the same from vehicle to vehicle.

Related question: if I leave the car “running” in my garage, AND plug in my L2 charger (FCCS), will that fully charge the 12V battery AND keep the HVB charged?

Yes, although it can take 12+ hours to fully charge the 12V battery. The car must be on. Plugging in the car is not enough.

If you are experiencing difficulties getting OTAs to install, I strongly recommend you follow the steps in my guide which covers all this: How To Get Failed OTAs To Install

 

[Jimrpa]

It depends on the update, some require more than others. 6.6.0 and 6.8.0 require higher 12V levels. I would recommend 80% or higher to get those to install. In some cases 80% may not be enough if your battery capacity is degraded. The actual threshold % is dependent on battery aging and is not the same from vehicle to vehicle.



Yes, although it can take 12+ hours to fully charge the 12V battery. The car must be on. Plugging in the car is not enough.

Sigh. So I’ll have to spend all day driving around at random just to get the stupid 12V battery to the right level? I’ve had the car on the charger to recharge it after driving it around to get it to 70%. I now have the HVB at about 80% and the stupid 12V battery is only at 76%? Sigh.

 

[Mach-Lee]

Sigh. So I’ll have to spend all day driving around at random just to get the stupid 12V battery to the right level? I’ve had the car on the charger to recharge it after driving it around to get it to 70%. I now have the HVB at about 80% and the stupid 12V battery is only at 76%? Sigh.

Yes, 12V is extremely slow to charge at the top end. Takes many hours.

 

[RickMachE]

Why I am setting up both EVs for a Battery Tender.

 

[Rt1AWD]

Why when the car is driving LVB is charging, but when the car is updating - the LVB is not charging.
It looks like a design flow.

 

[Mach-Lee]

Why when the car is driving LVB is charging, but when the car is updating - the LVB is not charging.
It looks like a design flow.

Because during module programming the communication busses have to go silent to give way to the programming traffic. This has been the case for the past two decades of automotive module programming. When the CAN busses are silenced, the PCM cannot control the 12V charging, so everything has to run off 12V battery only until programming is complete.

The bus-sleep programming mode was a limitation of module architecture on the Mach-E. It's not a design flaw per se, but will hopefully be improved upon in future EVs. Just "how it is", but I'm sure improvements are coming that will make future OTAs install easier.

 

[Rt1AWD]

Because during module programming the communication busses have to go silent to give way to the programming traffic. This has been the case for the past two decades of automotive module programming. When the CAN busses are silenced, the PCM cannot control the 12V charging, so everything has to run off 12V battery only until programming is complete.

The bus-sleep programming mode was a limitation of module architecture on the Mach-E. It's not a design flaw per se, but will hopefully be improved upon in future EVs. Just "how it is", but I'm sure improvements are coming that will make future OTAs install easier.

Why it is not implemented as a part of update process then: first the car charges LVB to the safe level and only after that starts an update.

 

[Mach-Lee]

Why it is not implemented as a part of update process then: first the car charges LVB to the safe level and only after that starts an update.

Maybe someday…

 

[Jimrpa]

This is so stupid. While it’s good to know the reasons, I still want someone to explain to me, in bunny rabbit English, why my Mustang Mach-E is the first car I’ve owned in over 30 years that I’m consciously aware of even HAVING a 12V battery ?

 

[generaltso]

Sigh. So I’ll have to spend all day driving around at random just to get the stupid 12V battery to the right level?

You don’t have to be driving. You can just disable the shutdown timer and leave the car on.

 

[Jimrpa]

You don’t have to be driving. You can just disable the shutdown timer and leave the car on.

Can I also leave the car plugged into my EVSE so I don’t drain the HVB?

 

[generaltso]

Can I also leave the car plugged into my EVSE so I don’t drain the HVB?

You can, but I wouldn’t be too concerned about draining the HVB. It won’t draw much. Just make sure the HVAC and headlights are turned off.

 

[jgcom]

In my family's experience with hybrid cars, 12 V battery aging and failure caused almost all of the drama in several otherwise solid and reliable cars. I wonder if we should just replace the darn things every 3 years whether they need it or not.

Sponsored