UPDATE: Failed 12v Battery....

[Adventureboy]

Do you know if Ford's AGM battery is a deep cycle?

I expect it is, and a deep cycle AGM will still age significantly faster when discharged below 50% SOC, especially if it sits that way for any period of time. I have been running deep cycle AGM batteries on my boat for years and can say this with certainty - AGMs need to be charged to 100% SOC daily and be kept above 50% SOC or they die.
Lithium batteries are happy at any SOC between 20%-90% and will be happy for years sitting at that SOC. I replaced the AGM on my boat with LiFePo4 5 years ago and the problems ALL went away.
All of the problems we see with the 12V battery would go away if Ford replaced that miserable little AGM with a small Lithium pack.

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[Adventureboy]

I’ve wondered about putting the MME on the 120V always and have it cycle through a departure time daily. Keep HVB at 80% but cycle HVAC, etc. even if car isn’t used. Weird trickle charger?

Interesting idea. I'm going to try this and see what happens to the LVB. The problem will still exist in the cases where you aren't plugged in for longer periods of time and want to conserve HVB.

The 5 days in the shop meant your 12V battery sat in a discharged state for 3-4 days - that's really hard on AGM batteries so not surprised you are seeing the messages now. The 90-mile daily commute would have kept it very healthy.

 

[John Becker]

I expect it is, and a deep cycle AGM will still age significantly faster when discharged below 50% SOC, especially if it sits that way for any period of time. I have been running deep cycle AGM batteries on my boat for years and can say this with certainty - AGMs need to be charged to 100% SOC daily and be kept above 50% SOC or they die.
Lithium batteries are happy at any SOC between 20%-90% and will be happy for years sitting at that SOC. I replaced the AGM on my boat with LiFePo4 5 years ago and the problems ALL went away.
All of the problems we see with the 12V battery would go away if Ford replaced that miserable little AGM with a small Lithium pack.

I've been wondering what the best way might be to deal with the 12 volt battery problem after I take delivery. I'm thinking that every time I plug in the high voltage battery to recharge, I should hook up the 12 volt charger too. What are your thoughts on that?

 

[Adventureboy]

I've been wondering what the best way might be to deal with the 12 volt battery problem after I take delivery. I'm thinking that every time I plug in the high voltage battery to recharge, I should hook up the 12 volt charger too. What are your thoughts on that?

My understanding is if you charge your HVB daily, you shouldn't need to charge the 12-volt battery separately unless you make only short runs and only use a short charge cycle. (I think they updated this with the major update a couple of months ago). I haven't verified this but I think it only charges the LVB when the HVB is actively charging. I might test this tonight to see if that is the case.

Putting a trickle charger on the AGM will keep it healthy but Ford should fix this. It seems really silly to have to put a $30 charger on a $100k truck to keep it happy when the truck is such a powerhouse. It means we have to unplug it twice before we can drive away, not to mention opening the frunk and putting the covers back in place.

 

[The Weatherman]

My understanding is if you charge your HVB daily, you shouldn't need to charge the 12-volt battery separately unless you make only short runs and only use a short charge cycle. (I think they updated this with the major update a couple of months ago). I haven't verified this but I think it only charges the LVB when the HVB is actively charging. I might test this tonight to see if that is the case.

Putting a trickle charger on the AGM will keep it healthy but Ford should fix this. It seems really silly to have to put a $30 charger on a $100k truck to keep it happy when the truck is such a powerhouse. It means we have to unplug it twice before we can drive away, not to mention opening the frunk and putting the covers back in place.

I believe you are correct. I have put a battery monitoring module on the 12V and it shows that it is charge when the HVB is being charged as well as when the truck is being driven.

My utilization is low so my truck may sit for 2, 3, or 4 days at a time. During that time it is charged to 90% so the LVB does drop off.

 

[Adventureboy]

My utilization is low so my truck may sit for 2, 3, or 4 days at a time. During that time it is charged to 90% so the LVB does drop off.

Out of curiosity, do you leave it plugged in for the down days or do you disconnect it from the EVSE?
I don't leave mine plugged in daily most of the year - I do in the colder winter months since I precondition the truck before leaving but not from April through October.

 

[gj00101]

Got this message yesterday.
“Electrical System Drain Service Required”

 

[The Weatherman]

Out of curiosity, do you leave it plugged in for the down days or do you disconnect it from the EVSE?
I don't leave mine plugged in daily most of the year - I do in the colder winter months since I precondition the truck before leaving but not from April through October.

I generally do not leave it plugged in. I usually remove the charger line within a day or so of charging it overnight.

If U find the 1v has dropped below 80% or so I will put the trickle charger on it and leave it until I make my next drive.

 

[Adventureboy]

In case anyone is interested, I tracked my 12V battery for several days and I only saw it charge in 2 scenarios:
1) While the truck in "ON"
2) While the HVB is being charged on Level 2 station.

Even with the truck plugged in, the 12V battery would drop once the HVB charge cycle ended. From Sept. 14th-15th the truck was plugged in however the 12v battery drained to 60% in about 30 hours. from Sept. 16th-17th it drained to less than 50% in about 36 hours and it was plugged in for the first 12 hours of that. There was a notable drop right about the time the truck was unplugged.

The graph is from the battery monitor, the Plug and HVB chaging status are from my charge logs in FordPass.

What did I learn? If the truck is not used for two days, the 12v Battery will deplete itself to catastrphic levels for the AGM even if plugged in. My next test (when able) I will let the truck sit for 2-3 days plugged in and for 2-3 days not plugged in to see if there is a safety mechanism built into our smart trucks when the 12v AGM drops below 50%. My challenge will be to find 3 days in a row where I won't need the truck so it could take a while for the results.

 

[The Weatherman]

In case anyone is interested, I tracked my 12V battery for several days and I only saw it charge in 2 scenarios:
1) While the truck in "ON"
2) While the HVB is being charged on Level 2 station.

Even with the truck plugged in, the 12V battery would drop once the HVB charge cycle ended. From Sept. 14th-15th the truck was plugged in however the 12v battery drained to 60% in about 30 hours. from Sept. 16th-17th it drained to less than 50% in about 36 hours and it was plugged in for the first 12 hours of that. There was a notable drop right about the time the truck was unplugged.

The graph is from the battery monitor, the Plug and HVB chaging status are from my charge logs in FordPass.

What did I learn? If the truck is not used for two days, the 12v Battery will deplete itself to catastrphic levels for the AGM even if plugged in. My next test (when able) I will let the truck sit for 2-3 days plugged in and for 2-3 days not plugged in to see if there is a safety mechanism built into our smart trucks when the 12v AGM drops below 50%. My challenge will be to find 3 days in a row where I won't need the truck so it could take a while for the results.

I concur with those findings.

 

[Adventureboy]

Update to above. My truck has been unplugged for 2 days now. In less than 48 hours, the 12V battery dropped to 50%. I got two messages on my FordPass, and shortly thereafter, the truck charged the 12V battery to full.

Some notable items:
1) HVB climbed from 85% (my set charge level) to 86% while not plugged in. Magic power I guess. I expect this is because the truck has shut down modules and it is taking a best guess just before shutting down connected services. It will be interesting to see what it says in the truck when I drive later today.
2) FordPass is not able to connect to the truck. Lock/unlock functions are not working and my last SOC update in FordPass was at the time of the message above. I can only guess that the truck has shut down the associated modules for a long-term deep sleep nap.

So it appears that Ford has some parameters to charge the 12V battery from the HVB when necessary even when unplugged. This is really good news.

The messages could be better, however, it could be that Ford simply hasn't gotten to that part yet, and due to the apparent shutdown of the communications modules, the truck isn't able to send messages until they are reactivated by vehicle entry. If not plugged in, it would be good a message before shutting down to say something like "Your 12-volt accessory battery has low voltage. It will be charged using your HVB and the truck will enter deep sleep mode to preserve energy" - at least then you would know not to expect FordPass to work.

I will try a similar 3-day scenario with it plugged in to see how it reacts.

I hope Ford is keeping an eye on the forums for continuous improvement ;-)

[Edit] One day later, FordPass is still not working. I went out and touched the door to unlock it (PAAK worked). Waited a few minutes and still no FordPass connectivity. I entered the truck and turned on the Accessories and a few seconds later, FordPass lit up. I expect it will stay active until the 12V battery runs down to 50% again.

 

[Adventureboy]

Final Unplugged results:

Summary: The truck charges the 12V battery from the HVB when it falls to 50% and goes into deep sleep mode. Once it enters deep sleep mode, the truck will no longer respond to FordPass as I expect it shuts down the modem module among others. The first time it did this after being unplugged, it sent two messages before shutting down the modem.

The second time (and I suspect subsequent charges) it did not send any messages but rather just went quietly into deep sleep. I suppose it can keep this up for months (maybe years) with a decent SOC to start with. My charge was set to 85% SOC at the beginning of this test and on the first 12v charge cycle, Fordpass reported 86% after being unplugged for 2 days just before it went into deep sleep. I activated the truck by turning on accessories for a few seconds so Fordpass was active for days 3-4 and after 4 days (just before deep sleep) it reported 85% SOC.

In my case, I get 2 days on the cycle before it enters deep sleep. I'm hoping it is because my 12v AGM is weak and it would normally be 5-7 days with a healthy battery. I also think the "Electrical System Drain Service Required" message is a result of the battery draining faster than expected due to its weak state and not due to an aftermarket device (which I do not have).

Recommendation to Ford: update the messages to indicate the truck is going into deep sleep mode so folks will know Fordpass won't work instead of getting frustrated and blaming it on glitches in the software.

In short: The truck protects the 12v battery. Communication with Fordpass users could be better.

I will try again plugged in when I can and see if the result is the same.

 

[TaxmanHog]

Awesome research and recommendations!!

Recommendation to Ford: update the messages to indicate the truck is going into deep sleep mode so folks will know Fordpass won't work instead of getting frustrated and blaming it on glitches in the software.

In short: The truck protects the 12v battery. Communication with Fordpass users could be better.

I will try again plugged in when I can and see if the result is the same.

 

[greenne]

In case anyone is interested, I tracked my 12V battery for several days and I only saw it charge in 2 scenarios:
1) While the truck in "ON"
2) While the HVB is being charged on Level 2 station.

Even with the truck plugged in, the 12V battery would drop once the HVB charge cycle ended. From Sept. 14th-15th the truck was plugged in however the 12v battery drained to 60% in about 30 hours. from Sept. 16th-17th it drained to less than 50% in about 36 hours and it was plugged in for the first 12 hours of that. There was a notable drop right about the time the truck was unplugged.

The graph is from the battery monitor, the Plug and HVB chaging status are from my charge logs in FordPass.

What did I learn? If the truck is not used for two days, the 12v Battery will deplete itself to catastrphic levels for the AGM even if plugged in. My next test (when able) I will let the truck sit for 2-3 days plugged in and for 2-3 days not plugged in to see if there is a safety mechanism built into our smart trucks when the 12v AGM drops below 50%. My challenge will be to find 3 days in a row where I won't need the truck so it could take a while for the results.

So looking at this.....can we conclude the LVB is charged(plugged in) ONLY when the HVB is actively charging? Would it then charge anytime the LVB is below 100%--charging it up to full?

It seems then, like a method to charge the LVB before it gets too low is to put the HVB in charging mode more often.

EDIT: I guess I'm looking to confirm there are two things that charge the LVB.... 1. Drive the truck, 2. Charge the HVB (not simply plugged in, but charging)

Under extreme circumstances the truck will charge the LVB from the HVB to keep it from failing(not plugged in, not charging)-- but this only kicks in below 50% and then puts the truck into deep sleep mode-- so we should avoid this if possible.

Am I getting this right?

 

[Adventureboy]

So looking at this.....can we conclude the LVB is charged(plugged in) ONLY when the HVB is actively charging? Would it then charge anytime the LVB is below 100%--charging it up to full?

It seems then, like a method to charge the LVB before it gets too low is to put the HVB in charging mode more often.

Correct. It charges in 3 scenarios that I've tracked so far:
1) When ON
2) When plugged in and only when the HVB is charging
3) When the failsafe for the 12v battery is reached (50%) - In this case the truck charges the 12v to 100% and goes into deep sleep mode. This test was only done with the truck unplugged so it could be different with the truck plugged in.

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