How to Recondition/Service Your 12V Battery

[P. T. Magoo]

Thanks guys. Glad to hear it's not a real common phenomenon now with these cars, and that the later versions of the software seek to better address LVB state of charge. I do wonder if it might be a good idea to hook something similar to this up though when the car first arrives, or after the dealer does software updates.

The other side of the coin for me, is that I have a 5 day/week 20 mile each way commute (so not just short trips), and several times a month a 90 mile each way commute, so if things are functioning as they should while the car is being driven, seems like the driving itself should counteract all that sitting in rail yards within a few weeks or months. Am I correct in thinking that? That's certainly what I would expect if it were an ICE vehicle with an alternator -- or a generator like my first car had.

I just don't want to get stranded by something that simple preventive maintenance would prevent.

Thanks again!

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[dtbaker61]

Thanks guys. Glad to hear it's not a real common phenomenon now with these cars, and that the later versions of the software seek to better address LVB state of charge. I do wonder if it might be a good idea to hook something similar to this up though when the car first arrives, or after the dealer does software updates.

The other side of the coin for me, is that I have a 5 day/week 20 mile each way commute (so not just short trips), and several times a month a 90 mile each way commute, so if things are functioning as they should while the car is being driven, seems like the driving itself should counteract all that sitting in rail yards within a few weeks or months. Am I correct in thinking that? That's certainly what I would expect if it were an ICE vehicle with an alternator -- or a generator like my first car had.

I just don't want to get stranded by something that simple preventive maintenance would prevent.

Thanks again!

I would say that driving 100+ miles per week means that your car is probably 'on' at least 3 hours/week. Since the 12v system comes up to 14.5+ volts when the car is on, if the 12v battery is low it will pick up energy pretty fast at first, and then slow down as battery voltage approaches system voltage.

3 hours 'on' per week *should* be plenty of time to dump a good chunk of energy in to maintain the LVB.

If you REALLY want to top it up before or after sitting for a week without driving.... you might want to turn on the car, disable the auto-off timer setting so it stays on, and leave it on maybe overnight.

 

[P. T. Magoo]

Based on posts in this thread and a lot of head scratching, I ultimately went with this one: BatteryMINDer 2012-AGM. About $100 on Amazon but it's cheap reassurance against a wonky LVB stranding me somewhere. I read recently on the forum that the welcome lights can sense your phone and turn on in the garage -- we spend a lot of time the room next to the garage so I'll be on the lookout for that.

LOL, when my car finally arrives I'll be loaded for bear in terms of information, thanks to this forum. Much obliged, folks!

 

[mkhuffman]

Based on posts in this thread and a lot of head scratching, I ultimately went with this one: BatteryMINDer 2012-AGM. About $100 on Amazon but it's cheap reassurance against a wonky LVB stranding me somewhere. I read recently on the forum that the welcome lights can sense your phone and turn on in the garage -- we spend a lot of time the room next to the garage so I'll be on the lookout for that.

LOL, when my car finally arrives I'll be loaded for bear in terms of information, thanks to this forum. Much obliged, folks!

This is great if it gives you piece of mind, but if the car is working properly, there is zero risk of LVB failure. I have done testing and with the latest software module updates, the car uses the HVB to keep the LVB charged even when the car is disconnected from a charger. Before I received the software updates the car only seemed to regulate the LVB when on or when plugged in, but now it works just as designed when unplugged and off.

You can do your own testing with an OBDII scanner to verify your car is regulating the battery when off. The scanner keeps some of the car's modules running which drains the battery in a few hours. If you let the car sit over night with the scanner monitoring the 12V, it should be enough time to see if the car starts recharging the battery at 40% like it is supposed to.

Here is what it should look like:

You can see that when the 12V battery gets to 40% SOC, the car recharges it back up to around 93%. This should happen if the car is unplugged and off. If it does not, you may need software updates. If it does, you are good to go! No worries!

BTW - your battery will not drain that fast if you don't have a load on it. The scanner puts a significant load on the battery because it causes various modules to stay on even when the car is off. It isn't the scanner draining the battery, it is the result of the scanner interacting with the car and measuring the data in the car. So I personally would not do this test multiple times as I am sure it is not good for the LVB to drain it down to 40% over and over.

 

[dtbaker61]

... I read recently on the forum that the welcome lights can sense your phone and turn on in the garage -- we spend a lot of time the room next to the garage so I'll be on the lookout for that.

my home office is right next to the garage... and I make many trips per day from one end of the house to the other, to office or garage workshop. Each time you leave and come back into BT range, your car will wake up and welcome lights come on. The wakeup and welcome does take a little 12v energy, and it also makes a host of clicks and clunks as contacts open and close in the wake up and back to sleep process.

I usually just shut down BT on my phone when I am home since I don't use BT for anything else from my phone when I'm home, or do a 'force stop' of the FordPass App... and then fire it back up when I am headed out to drive somewhere so PAAK has time to re-connect on approach when I am actually getting ready to drive somewhere.

 

[alangant]

My home office and my den are both within BT range of the garage. When I get my MME, will it be waking up (or staying awake) for hours on end in these conditions?

 

[generaltso]

My home office and my den are both within BT range of the garage. When I get my MME, will it be waking up (or staying awake) for hours on end in these conditions?

My car only wakes up the first few times I go near it. After that, it stops waking up.

 

[Mach-Lee]

Here's my alternative way of battery reconditioning without having to remove the frunk covers or drill holes, I am using an OBD-II memory saver cable. The data link connector (DLC) has constant-on power, so we are able to backfeed the small amount of current needed to recondition through it. You must use a power supply or charger that is limited to 4 Amps max, otherwise you can overload the small wires to the connector. Also be careful to keep the nose of the 12V connector from touching anything once plugged in, if the nose touches metal it will short circuit the 12V. There is a 7.5A fuse inside, but still wise not to make shorts. Keep your positive and negative covered/separated so they can't touch if bumped. I still have some time to go to reach current minimum.

 

[Mach-Lee]

Update: Finally reached current minimum after about 60 hours of charging @ 13.60V, final value around 49 mA. Testing on another BHAGM-H3 battery shows a current min of about 15 mA, so that means the idle draw of the car is around 35 mA, which is normal. My battery should be fully conditioned now, we'll see if I get any 12V errors in the future.

 

[VegStang]

Thanks for the video and writeup, along with the other tips. I initially thought I could connect directly to the battery and avoid taking off the driver side trim panel (lost one of the clips into the black hole from the top panel,) but after referencing this forum I see otherwise.

 

[Mach-Lee]

I've updated this topic with current information on known 12V drain causes, and the recall.

 

[Shayne]

I've updated this topic with current information on known 12V drain causes, and the recall.

Did you add the HVJB pos contact can stick open in the cold and drain/not charge your 12V battery. At that point it is best to recondition it as per your guide and then keep it on a charger/maintainer while parked (some smart lower amp chargers error out due to large battery drains from this vehicle that they view as an error 15amp works fine here). Thinking some problems may not even have hit the boardroom table yet. Hoping this one may be taken into account in the resign but who knows.

 

[KennyPratt42]

I brought this up in its own thread, but here might be a better place.

I was informed by my dealer that my in transit Mach-E is currently stuck at the shipping yard in Kansas City with a 'dead' 12V battery because they can't get it to move. Has this happened very often in transit (it shipped out very quickly after it was built, maybe a day or two) and is the solution that they get a new 12V battery to replace at the shipping yard?

 

[mkhuffman]

I brought this up in its own thread, but here might be a better place.

I was informed by my dealer that my in transit Mach-E is currently stuck at the shipping yard in Kansas City with a 'dead' 12V battery because they can't get it to move. Has this happened very often in transit (it shipped out very quickly after it was built, maybe a day or two) and is the solution that they get a new 12V battery to replace at the shipping yard?

Yes, other forum members have reported this happening. I have not seen a post about that in a few months, but several forum members had to have the 12V battery replaced before (some after) the car arrived at the dealer.

It is rare, but you are not alone.

 

[louibluey]

Update: Finally reached current minimum after about 60 hours of charging @ 13.60V, final value around 49 mA. Testing on another BHAGM-H3 battery shows a current min of about 15 mA, so that means the idle draw of the car is around 35 mA, which is normal. My battery should be fully conditioned now, we'll see if I get any 12V errors in the future.

Just finished conditioning my new spare battery with a final current around 12 mA after a couple of days. BTW, it's for sale https://www.macheforum.com/site/thr...h3-35ah-mach-e-12v-battery.19377/#post-458403 as my GTPE if it happens, is probably a year away.

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