12 Volt battery?

[MustangBarry]

Perhaps I am not understanding. If the HVB tops off the 12V as needed unless the car "goes to Sleep", wouldn't this ensure the 12V would not go dead as long as I have more than the minimum charge in the HVB?

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[Adventureboy]

So if I'm going to be away for more than two weeks couldn't I just do a lock/unlock sequence via Ford Pass every few days to keep the car from "going to sleep"?

My experience is no. If the 12v battery drops to below 50%, the car will charge it from the HVB and go into deep sleep. It shuts down the modem that FordPass uses along with many other modules to conserve energy. To my knowledge, the only way to reactivate the modem (and FordPass) is to get in the car and start it.

 

[generaltso]

The only exception is if you have a very cold snap and your MME tries to keep the HVB battery warm - it will use more HVB SOC then.

That doesn't happen if the car is not plugged in.

 

[Adventureboy]

Perhaps I am not understanding. If the HVB tops off the 12V as needed unless the car "goes to Sleep", wouldn't this ensure the 12V would not go dead as long as I have more than the minimum charge in the HVB?

Actually, the HVB will keep topping up the 12v battery even after the car goes into deep sleep. It retains some modules like the bluetooth module so the keys/PaaK will work when you walk up to the car and this continues to draw on the 12v. I've tracked it and watched it cycle 3 times. The first time it put the car to deep sleep. The 2nd and 3rd time it just topped up the 12v battery because the car was already in deep sleep.

 

[Adventureboy]

That doesn't happen if the car is not plugged in.

You are probably right. Info is sparse on this. I would like to stay up on these things if you have additional sources. The cells are rated to -20ºC and we get colder than that here so it is important to us in the GWN when things get frosty and no plugs are available.

 

[Pmullin7]

If it will be in storage for months, the HVB should be kept closer to 50%. And once the car goes into deep sleep, it's not going to wake up to top off the LVB. So I'm not sure I'd be suggesting that advice over what Ford says to do.

You can access the vehicle via Ford Pass remotely once every few days, drag down on the app to force a refresh. That seems in my experience to prevent deep sleep. I just did this on a two-week vacation and monitored the 12-volt battery as well, The HVB did once recharge the low voltage battery taking it from mid-40s percentage up to mid-80s percentage.

I left the car at 60% charge and returned to find it still at 60. Which makes sense that it would take very little power to recharge the 12 volt battery and run the computers.

 

[TheVirtualTim]

The 12v is monitored and _if_ the state of charge is low, the car will charge it in one of two ways:

1. If you are driving, it will use the HVB to charge the LVB.
2. If you are charging, it will use the AC power to charge the LVB.

If you are not driving or charging then the 12v is not normally charged. But it should switch to "deep sleep" mode if the 12v power dips to low. "deep sleep" disables several modules that are normally left running when the car is off and this lets it reduce how much 12v power is needed.

Charging the 12v is not a fast process ... it can take hours. A quick trip to the local grocery store wont be enough to do much.

The software update list indicates that there was an update that is meant to improve handling of the 12v battery. I do not know the details of what this does.
https://github.com/elmedico27/fordpowerup

 

[Adventureboy]

The 12v is monitored and _if_ the state of charge is low, the car will charge it in one of two ways:

1. If you are driving, it will use the HVB to charge the LVB.
2. If you are charging, it will use the AC power to charge the LVB.

If you are not driving or charging then the 12v is not normally charged. But it should switch to "deep sleep" mode if the 12v power dips to low. "deep sleep" disables several modules that are normally left running when the car is off and this lets it reduce how much 12v power is needed.

Charging the 12v is not a fast process ... it can take hours. A quick trip to the local grocery store wont be enough to do much.

The software update list indicates that there was an update that is meant to improve handling of the 12v battery. I do not know the details of what this does.
https://github.com/elmedico27/fordpowerup

Add 3. If your 12v battery drops below 50% it will charge from the HVB always (plugged in, not plugged in it will do this otherwise the car will be dead after 5-6 days.)

Here is the chart from my independent monitor while not plugged and not used over several days. I think there have been several updates to the charge parameters and deep sleep parameters over the last 18 months so the version you are on might vary slightly for when it charges and when it goes into deep sleep. If will maintain the 12v battery in all versions.

It takes about an hour to charge the 12v from 50% to 100%. No noticeable drop in HVB SOC.

 

[dww]

Add 3. If your 12v battery drops below 50% it will charge from the HVB always (plugged in, not plugged in it will do this otherwise the car will be dead after 5-6 days.)

Here is the chart from my independent monitor while not plugged and not used over several days. I think there have been several updates to the charge parameters and deep sleep parameters over the last 18 months so the version you are on might vary slightly for when it charges and when it goes into deep sleep. If will maintain the 12v battery in all versions.

It takes about an hour to charge the 12v from 50% to 100%. No noticeable drop in HVB SOC.

Hi, I'm the one that started this thread. From the graph above it amazes me that the 12V battery would go down so fast.

Anyway, when we leave our Mach E for 2 months......should we allow it to sleep and have the software handle the time off, or just leave it plugged into our 40Amp circuit so that it never goes to sleep, or lastly should I try and turn it on remotely every week for an hour?

Thanks so much

 

[Teslaeata]

Perhaps I am not understanding. If the HVB tops off the 12V as needed unless the car "goes to Sleep", wouldn't this ensure the 12V would not go dead as long as I have more than the minimum charge in the HVB?

Correct? though even if car “goes to sleep” once 12v drops below 40% DC/DC inverter will soon start to charge 12v battery. If drops to 30% will charge immediately.

 

[Adventureboy]

Yes, when I did this test, my 12v battery was weak. That is why I installed the monitor to track it. It should probably take 4-6 days for the cycle that shows in 2 days in my graph. My battery has been replaced since then.

In your case, for 2-2.5 months, you will likely be ok regardless of which way you do it. If it were mine, I would have the SOC at 30-50%, disconnect the 12v battery (negative terminal), and connect a 12v AGM battery maintainer to the LVB. This will keep the 12v battery in good health and store the HVB in the optimal state for longevity.

The difference is minor however if you leave it plugged in, set the SOC to 50%. This will maintain the HVB without over-energizing it unnecessarily. Adding a 12v AGM battery maintainer to the LVB will keep it from cycling as shown in my graph. This will keep it healthier and overall less wear and tear on it. A 3-10amp maintainer should be adequate for long periods of inactivity. I use a 10 amp.

 

[OrchidMania]

Today I got a notice in my FordPass that a service technician determine my 12 volt battery is low. The last time I was at the dealer was for my HVBJB replace in early February. 3 months ago
What is this??

 

[Space_Pony]

Today I got a notice in my FordPass that a service technician determine my 12 volt battery is low. The last time I was at the dealer was for my HVBJB replace in early February. 3 months ago
What is this??

Did your service tech tell you 3 months ago that your battery was getting weak? If not, I would monitor it and if it drops below 50% regularly and doesn't charge to 90% after driving, have it tested.

 

[OrchidMania]

Did your service tech tell you 3 months ago that your battery was getting weak? If not, I would monitor it and if it drops below 50% regularly and doesn't charge to 90% after driving, have it tested.

The dealer said nothing 3 months ago. How do I monitor the 12v? PS I love this forum. My husband is now going to drill access holes to the 12v. He wants to have the plugs here before drilling

 

[Space_Pony]

The charge level listed is your lvb soc.

https://www.ford.com/myaccount/

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