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How to properly charge a battery with the BMS systems.

4K views 12 replies 4 participants last post by  Bluegrass 
#1 ·
#2 ·
Here is another good video from MAKULOCO on how to properly charge your battery with the BMS systems from ford authority. This keeps the BMS updated of batteries state of charge without the need to sit for 8 plus hours isle.

Ford Battery Monitoring System Explained In Depth By Technician (fordauthority.com)

BD
Since I retired I end up mostly taking short trips. Some weeks only to the grocery store and back, 3 miles round trip. I was shocked, but after I thought about it for a minute it made sense, after getting the prompt for the system shutting down the infotainment screen as I started the car that my battery, not even a year old was slowing being drained from the cold and not being driven much, or for long. Took 6 hours on a 4amp trickle to bring it back fully. I had turned off the phone app features and monitors after I bought the car back in January to save battery power. Now I'm just gonna trickle charge the car every few weeks and leave the plastic batter box lid off over the winter for quick access (and to keep from dropping one or more of those pesky plastic hold downs into the engine bay). I might even turn the FordPass monitoring back on, but I hate the idea of my car monitoring itself (or me).
 
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#3 ·
I have a battery tender style quick connecter on my battery positive terminal and the ground on the right strut tower that has the old-style current monitor around it so I can leave the battery cover on and just connect trickle charger to the quick connect for maintenance charging. Mine is actually on trickle now since I am in the same category as you and drive very little and mostly short trips as well. I use the ford pass app to alert me to when the battery is getting low and needs to be put on charge since it gives a message in bold red stating that the system is in conservation mode.

Ring Terminal Accessory Cable

Most motorcycle shops and parts houses will have them for sale.

BD
 
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#4 ·
I have a battery tender style quick connecter on my battery positive terminal and the ground on the right strut tower that has the old-style current monitor around it so I can leave the battery cover on and just connect trickle charger to the quick connect for maintenance charging. Mine is actually on trickle now since I am in the same category as you and drive very little and mostly short trips as well. I use the ford pass app to alert me to when the battery is getting low and needs to be put on charge since it gives a message in bold red stating that the system is in conservation mode.

Ring Terminal Accessory Cable

Most motorcycle shops and parts houses will have them for sale.

BD
I've looked at them recently. I might just end up getting one for my baby so I can put the lid back on and make life even easier.
 
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#8 ·
So I skimmed that video instead of just reading the article and it looks like he’s talking about a sensor on the battery terminal so the truck can tell that it’s being charged by an outside charger.

My 16 doesn’t seem to have that sensor on the battery, is it on 2016 cars? I have seen the “system off to save battery” warning and getting 2010 bings and bongs before I hooked up this tender after it seems to be fine.

maybe I’m just not understanding how This sensor wouldn’t be able to tell there Is a current going into the battery. For the system to work it would have to monitor the battery voltage, amperage and charge level. If that increases it should be able to tell regardless of where you grounded off as long as it’s a good solid ground.

I should also mention that it’s the freezing rain part of winter where I live and we’re heading into cold as fuck -25 to -45 part of winter and the car has been parked for the majority of winter so far. Only being taken out for 4 days while I was waiting for an alternator to come in the mail for my daily driver. I usually start it once every 2 weeks or so just to move the oil around, make sure the fuel pump doesn’t seize, etc but other than that the car doesn’t do anything. In the summer it’s not connected to this system
 
#9 ·
Your car has the old style band type sensors he shows in the video at the 5.00 minute mark when he goes out to his 2016 truck, it is the black round donut looking thing around the battery cable. Our ecos have one around the negative cable about 3" from where the ground cable attaches to the right strut tower and one around the positive cable just below where it connects to the under-hood fuse box, it's the center cable if you remove the fuse box lid.

With the ground ring terminal connected the way you have it now to the battery post the current is not going thru the sensor on the ground cable so the BMS system is not seeing that the battery is being kept fully charged, if you move it to the strut tower ground cable connection point then the sensor will see the current going thru the cable and therefore the sensor will sense the battery is being kept fully charged. Don't concentrate on the info about his 2021 truck but rather what he shows on his 2016 truck in the video that's out in the parking lot.

The way you have it connected now will still charge the battery and keep it fully charged it just does not allow the BMS module to recognize you are keeping it charged. I hope that clears it up and makes it easier to understand.

BD
 
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#11 ·
i understand that part and that the car doesnt know its connected to a battery maintainer i just dont understand why it would need too. it should be monitoring battery voltage the entire time the vehicle is on. and even if it didnt know it was being charged while parked it should clue in fairly quickly after the engine is started that the battery is almost full.
I agree but I believe the only way it monitors the battery state of charge is with those current sensors on the main battery cables not the battery voltage itself. It's how it knows if the alternator is working correctly or not by the current the sensors are measuring. The new system does monitor right at the battery itself but not the old style like on out ecos. I am just going by what the video shows and had mine hooked the same as you do at first and even with the battery fully charged when I would drive the car fresh off the charger it would be charging at 15 volts for several miles before it dropped. Now it starts at 14.5 max before it drops.

BD
 
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#12 ·
I agree but I believe the only way it monitors the battery state of charge is with those current sensors on the main battery cables not the battery voltage itself. It's how it knows if the alternator is working correctly or not by the current the sensors are measuring. The new system does monitor right at the battery itself but not the old style like on out ecos. I am just going by what the video shows and had mine hooked the same as you do at first and even with the battery fully charged when I would drive the car fresh off the charger it would be charging at 15 volts for several miles before it dropped. Now it starts at 14.5 max before it drops.

BD
ok makes sense, thanks
 
#13 ·
For all that wonder why chassis ground must be used.
The Neg Battery cable is a special cable made with a calibrated Resistance.
The Sensor has a Micro Processor that monitor the voltage drop across the ground cable calibrated resistance.
The charge currant passes through this resistance and is measured by the Sensor and sent to the BMS program in the Body Control Module so the BMS adjust it's control actions.
 
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