Not the use of ProPower I expected… charging 12v battery

[Ragman]

Sorry Ford these 12v issues are becoming a PIA - truck was sitting on charger at 100% state of charge with departure set for 8:20 - at 8:24 truck alarm goes nuts with a frunk opened message in FordPass.

Truck won’t respond to anything and gives every error under sun. Now it’s completely dead…. They should not fail this “hard”.

Stuck a 25 amp booster on it, truck goes click and hop in truck powers right up. Disconnect and cycle truck again and no issues starts fine. I did not recharge the battery in 15 seconds on charger.

Change the software…. Recharge at 50% not 30% and get rid of the 48 hour logic…

This is our third truck with 12v issues.

 

[CD4TNF]

Weird. I left my lights on and I got a bunch of messages on FordPass letting me know the 12V was dangerously low. I was at an event so it took me over 2 hrs to get back to the truck. Basically the truck was begging me to plug it in and let it charge up the 12V. I was very nervous because the last message on FordPass basically made it sound like the 12V was done for.


Headlights were on. Got in the truck and it started just fine. No issue. I was pleasantly surprised at the number of notifications I got warning of the 12V battery drain.

Sorry your 12V is bricking itself so suddenly. It's just so different than what I experienced.

 

[Ragman]

I’m curious what year/build date is yours? That warning notice makes complete sense we’ve never gotten one 12v warning. This truck is 03/23 build date.

 

[GoodSam]

Do you have the new Battery Monitoring Sensor on the 12V battery Negative post? CSP 23B70 . That seems to have helped a lot of folks.
https://www.f150lightningforum.com/...-150-lightnings-bms-sensor-replacement.17900/

 

[RickLightning]

You are not charging that battery properly. You need to put the negative cable on a ground screw or the negative jump post. In fact, put both cables on the jump post.

What you are doing is bypassing the BMS and therefore the truck will not know the proper state of charge of the 12v battery, and will not maintain it properly.

 

[Stephen8810]

From another forum posting

 

[MaintGrl]

From another forum posting

Thank you for that reminder, I have NOT had the need to Jump my truck, and my mechanical intuition would have told me to hook up straight to the battery posts, but I guess the Truck would not know power is returning to the 12v battery...

 

[RickLightning]

Thank you for that reminder, I have NOT had the need to Jump my truck, and my mechanical intuition would have told me to hook up straight to the battery posts, but I guess the Truck would not know power is returning to the 12v battery...

Use the jump posts under the passenger side panel, that's what they are for.

 

[Ragman]

Yep I did catch that and used the posts after taking pictures, interestingly I put it on charger overnight and only showing 60% after 12+ hours at 5 amps. The voltage pre-boosting (dead truck) was 5 volts - immediately after was 14.8 with truck “running” then 13.6 “off w/o charger”.

Tentatively booked into Ford in two weeks to do recall and check battery. All I can find locally are H4 batteries no one stocks the small H3s…

 

[PrimeRisk]

Use the jump posts under the passenger side panel, that's what they are for.

Yeah, removing the passenger side panel is a PITA. I popped off the bottom half of two of the twist connectors the first time I removed it and had to go fishing for one of them in the void for 5 minutes. In reverse, it took about 5 minutes of jiggling them around to get them in the right position to put it all back together.

Not a very user friendly access. I opted to put D-Ring connectors on the correct positions after the BMS sensor to have a quick-connect solution by just pulling off the battery door. It worked perfectly to put it on a BatteryMinder while we went to Europe for 2+ weeks. Came back to a fully charged 12v and a software update.

 

[Runaway Tractor]

How is this not just actual negligence on Ford's software dev team?? There's 130kwh of power in the HVB. There's a DC-DC converter to keep the LVB charged. Battery low, hmmm, maybe now would be a good time to turn the DC-DC on and recharge?? NAH. Let's let it die and just throw senseless error codes, that sounds cool.

 

[Ragman]

Even had they gone with an H4 or H5 battery - space really isn't an issue in that area the tray is massive with this little "lawn mower" sized battery to power everything. I'm very tempted to stick in a 50 Ah H4 and see what it does... Apparently the tray (at least in Mach-E) actually has holes for the tie downs to secure an H4 to replace the H3.

I suspect the root of this is during "Departure Conditioning" the truck is in a special state - not on but not off - so that the 30% must charge now override isn't available in Ford's programming. The LVB was likely at <40% say 31% (for less than 48 hours) when pre-conditioning started it took the truck well below 30% to a point the truck was "dead". Anyone stuck a scanner on the truck and measured before/after LVB on a pre-condition (warm cabin w/seats and heated wheel on).

 

[TaxmanHog]

Even had they gone with an H4 or H5 battery - space really isn't an issue in that area the tray is massive with this little "lawn mower" sized battery to power everything. I'm very tempted to stick in a 50 Ah H4 and see what it does... Apparently the tray (at least in Mach-E) actually has holes for the tie downs to secure an H4 to replace the H3.

I suspect the root of this is during "Departure Conditioning" the truck is in a special state - not on but not off - so that the 30% must charge now override isn't available in Ford's programming. The LVB was likely at <40% say 31% (for less than 48 hours) when pre-conditioning started it took the truck well below 30% to a point the truck was "dead". Anyone stuck a scanner on the truck and measured before/after LVB on a pre-condition (warm cabin w/seats and heated wheel on).

IIRC, the DC/DC inverter does activate during departure timed start and remote climate start.

I observed this on the FORD.COM account status page back when we could see the LVB SOC, {can't see it there anymore}

 

[bmwhitetx]

Tentatively booked into Ford in two weeks to do recall and check battery. All I can find locally are H4 batteries no one stocks the small H3s…

Try the Quick Lane at your dealer. When I had an issue I took it to the Quick Lane and they checked it right then and there.

 

[Runaway Tractor]

The topic of a larger capacity LVB has come up before. Several here suggest it will not work properly because the LVB has that little BMS to monitor state of charge. IF the LVB BMS is monitoring amps out vs amps in, and knows what that small LVB capacity is supposed to be, that may be a problem. Really depends how Ford programmed all that and I don't think anyone here knows for sure. Just speculation as far as I know.

If you try it, please do let us know how it goes.

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