Monitor your 12Volt battery

[JoeBeach]

I just received my first "Low Battery Warning" with no explanation but "ok" to clear it. I am guessing this must be the LVB since iI have 70% indicated for the HVB. The car sat without charging for a few weeks so I am guessing that is why, but I have driven it a bit since then before the warning came on. Is there some way of seeing the state of the battery without adding meters and monitors? Also, my owners manual is no longer on my main screen . I got a meesage saying CX727 or something like this is not available. I have v3.1.4. These two events are probably not connedcted but I have no idea what is happening. Does the LVB charge while you are charging your HVB?

Sponsored

 

[theriddler]

Whew, looks like some people read this as someone saying we NEEDED to do this to monitor our 12V batteries. I read it as, 'hey, we know there is a flaw with how Ford designed this as it may not be alerting us when there is a 12V issue that may leave you stranded so I am doing this for peace of mind".

OP...as a new owner I appreciate the input and am trying to soak up as much information and heed as much preventive advice as possible to make my enjoyment of this great vehicle continue long term...so thank you.

 

[HuntingPudel]

I just received my first "Low Battery Warning" with no explanation but "ok" to clear it. I am guessing this must be the LVB since iI have 70% indicated for the HVB. The car sat without charging for a few weeks so I am guessing that is why, but I have driven it a bit since then before the warning came on. Is there some way of seeing the state of the battery without adding meters and monitors? Also, my owners manual is no longer on my main screen . I got a meesage saying CX727 or something like this is not available. I have v3.1.4. These two events are probably not connedcted but I have no idea what is happening. Does the LVB charge while you are charging your HVB?

Answering your questions kind of in reverse. ??

No, the LVB does not charge every time the HVB is being charged. It is supposed to charge from the HVB when it is 40% SoC or lower. If you drive the car, the LVB is supposed to charge pretty much the same way. Some people recommend running the car (press brake pedal, tap the On/Off switch) for at least an hour to ensure an adequate amount of time to transfer energy to the LVB. I rarely drive for that long of a period. ?‍?

It does not hurt to occasionally charge your LVB. I hook mine up to a charger once in a while (twice since I got the car in nov ‘21). I hook up to a regulated power supply every time I program the car. ??

You can see the SoC of the LVB if you have an OBD-2 reader. There are several on the market compatible with smartphones. Use the CarScanner app to get information in a readable format. ??

 

[JoeBeach]

Ok a rant that you have all heard before. The idiot engineer of the year award goes to the genius that put the battery under two pieces of plastic. The second place award goes the the guy that designed the plastic pieces designed to almost break before you get them off and the clips designed to stay on the car instead of on the piece it is supposedly holding together. Why in God's name were these designs allowed to appear on $60,000 car? This smacks of Suburu engineering. And then you have an strange U shaped positive terminal post. Maybe it is just me but I have never before seen such a battery post and how do you connect to it other than a clamp? Weld?

 

[DevSecOps]

No, the LVB does not charge every time the HVB is being charged.

I would say this is incorrect. The LVB does charge every time the car is driven or is being charged on L2 or L3 (I have never tested on L1). I have 172 days, 23 hours of data, monitoring and graphing the LVB, which is completely unnecessary by the way.

Either way, unless the 12v discharge message is continual I would disregard it. Unless there's something seriously wrong, your under 12% SOC or you have a major power drain your car will keep the LVB up just fine. They honestly should have worded the message differently and I don't recommend spending money on a 12v monitor.

 

[JoeBeach]

I received a low voltage warning again and checked the battery and it was at 12.8 volts. I decided to charge it and of course hasd to take the car apart and then clamp on to the strange positve pole and the ground and I see with my BattteryMinder that the battery is weak and it is desulfating it wiith charging to follow. So we will see what 12 hours of charging does for it. From what I can see the positive pole of the battery is buried in the battery box and that U shaped thing is just a connection for clamps but defeats putting a BatteryMinder on with normal terminals with out removing the frunk.

 

[Mach-Lee]

I received a low voltage warning again and checked the battery and it was at 12.8 volts. I decided to charge it and of course hasd to take the car apart and then clamp on to the strange positve pole and the ground and I see with my BattteryMinder that the battery is weak and it is desulfating it wiith charging to follow. So we will see what 12 hours of charging does for it. From what I can see the positive pole of the battery is buried in the battery box and that U shaped thing is just a connection for clamps but defeats putting a BatteryMinder on with normal terminals with out removing the frunk.

If the BatteryMinder says it’s low I recommend charging it for 48 hours so it has time to completely clear out the sulfation.

Way more about charging the 12V here: https://www.macheforum.com/site/threads/how-to-recondition-service-your-12v-battery.11069/

 

[Deleted member 5795]

@Sweetwater I cant find that device on Amazon that you got and I would like to get one too. Any chance you could post the link?

 

[DevSecOps]

I received a low voltage warning again and checked the battery and it was at 12.8 volts. I decided to charge it and of course hasd to take the car apart and then clamp on to the strange positve pole and the ground and I see with my BattteryMinder that the battery is weak and it is desulfating it wiith charging to follow. So we will see what 12 hours of charging does for it. From what I can see the positive pole of the battery is buried in the battery box and that U shaped thing is just a connection for clamps but defeats putting a BatteryMinder on with normal terminals with out removing the frunk.

I think you're over thinking this whole thing.

1 - If you haven't charged the car in weeks it's completely normal for the DC/DC inverter to engage to top off the 12v LVB from the HVB. Especially if the drives were just short trips.

2 - The LVB will discharge with accessories connected, OBDII dongles connected or just by walking by the car many times triggering the welcome lighting.

3 - Taking the current voltage really means nothing. The LVB goes through huge swings in voltage throughout a day. At one point in time it really doesn't mean anything. That being said, 12.8v, from my logging, is actually on the high end of normal for an inactive state.

4 - The driver's side panel is all you need to remove. You have both the neg and pos terminals right there, you don't need to get to the actual battery.

5 - If you want easier access to those terminals for less than $5 go here: https://www.macheforum.com/site/threads/guide-better-jump-point-access-battery-access.10976/

6 - The message, in of itself, is actually a good thing if the conditions exist that would cause it to trigger, which it sounds like they exist in your case. This means that the car is doing what it's supposed to do.

Here's an example of the voltage swings in the LVB:

 

[21st Century Pony]

My now fairly older Escort Passport radar detector LED display also lets me monitor the 12V battery state of charge, which btw. seems to vary more than it used to after the latest big APIM software upgrade. It used to just sit there on the 14V .decimal level, and now it shifts often between the high 12V .decimal and the 14V .decimal levels.

I use the Escort all the time in my travels unless I'm back home in Virginia where they are still illegal... back home the OP's cigarette port device would also be useful for me. Thanks for the OP's post.

 

[Old_Norm]

@Sweetwater I cant find that device on Amazon that you got and I would like to get one too. Any chance you could post the link?

https://www.amazon.com/Battery-Charging-Condition-Alternator-Display/dp/B07422ZPT4

It appears that one is out of stock. Here's another one:
https://www.amazon.com/dp/B000EVWDU...comp-feature-scomp-feature-scomp&ref=aa_scomp

 

[Shayne]

My Mach has been sitting just over a week. I went out to check
my 12 v battery and it is 14.43 v. This tool has helped me not to
worry and provides a way to check that LVB issues.
Not much money for pease of mind.

Old but not mentioned.

Your battery is not at 14.4 V that is when it is on and charging it? You need to shut it down open the door and close it to see the 12V voltage. Now I see 15.2 V charging a lot and normally I see it around the 12.3 V when reading the battery after power off on the 12V plug in. You can tell it may be low by how the door pops I have found. An OBD2 is the best tool to read the 12V.

Here's an example of the voltage swings in the LVB:

You can see it go up to 15V to charge the 12V pretty easy on that graph. It should look after itself and we never hear from it. This winter it is surviving ?. New mode that comes on now preparing for drive is shown in ford pass but it is auto. 1 to 2 times a day for 15 20 minutes. Hear the recirc pump and maybe thawing out the contact? It has made a few -30F this winter in which the 12V would not have survived last. Things are improving here. Get departure scheduling working and happy camper.

 

[Deleted member 5795]

https://www.amazon.com/Battery-Charging-Condition-Alternator-Display/dp/B07422ZPT4

It appears that one is out of stock. Here's another one:
https://www.amazon.com/dp/B000EVWDU...comp-feature-scomp-feature-scomp&ref=aa_scomp

Thank you very much @Old_Norm !

 

[DarkStang]

Anyone else feel like the battery drains more than it should? I have no accessories attached, no ODB left in, and have disconnected any third party apps and I still see some major drain overnight.

According to CarScanner, my LVB may be at 75% SOC and a day or 2 later without charging the HVB and it’s down to like 50%. Voltages are still ok and enough to turn on the car, but I’m worried about how much cycling it’s doing and how it could affect its life. Quiescent drain is only 55 mA which I think is normal for a modern car with a lot of electronics.

Disabled welcome lighting and walk away locks in hopes that my phone being too close while at home is waking it up, but seems to make no difference. Is it normal and healthy to have frequent SOC swings on the LVB?

 

[Mach-Lee]

Anyone else feel like the battery drains more than it should? I have no accessories attached, no ODB left in, and have disconnected any third party apps and I still see some major drain overnight.

According to CarScanner, my LVB may be at 75% SOC and a day or 2 later without charging the HVB and it’s down to like 50%. Voltages are still ok and enough to turn on the car, but I’m worried about how much cycling it’s doing and how it could affect its life. Quiescent drain is only 55 mA which I think is normal for a modern car with a lot of electronics.

Disabled welcome lighting and walk away locks in hopes that my phone being too close while at home is waking it up, but seems to make no difference. Is it normal and healthy to have frequent SOC swings on the LVB?

That’s high, my drain is only 23 mA. Anything above 50 is abnormal, something is drawing power or not shutting down.

Sponsored