Ford BMS Battery Monitoring System: How it Works and How to Properly Charge Your Battery!

AzScorpion

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Found this video explains the BMS system. It shows how you should jump start and charge it too. So many have never had this system (myself included) and there's always questions about what to do with these. Overall a good helpful video but the guy does get a little repetitive towards the end.

Yes, this probably qualifies for the longest thread title on here. 😜


 

Trigganometry

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Good video Dave. I didn’t realize that Forscan had this feature. My Ctek charger is with remote hookup is on the frame and positive terminal. Might change the ground location on the negative side as shown here. Just make for a more efficient system.

As a note to others on here. Our factory settings in the BCM have the charge capacity set to 70% of total capacity from factory. Probably done to give longevity to the battery. The negative side of that is at full charge less than 75% of capacity is available. I changed mine to 90% not long after I got the truck almost 2 years ago. Doesn’t seem to of had a negative effect on the battery doing that.
 
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AzScorpion

AzScorpion

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Good video Dave. I didn’t realize that Forscan had this feature. My Ctek charger is with remote hookup is on the frame and positive terminal. Might change the ground location on the negative side as shown here. Just make for a more efficient system.

As a note to others on here. Our factory settings in the BCM have the charge capacity set to 70% of total capacity from factory. Probably done to give longevity to the battery. The negative side of that is at full charge less than 75% of capacity is available. I changed mine to 90% not long after I got the truck almost 2 years ago. Doesn’t seem to of had a negative effect on the battery doing that.
IIRC Rick the directions on the Ctek specifically say to mount the ground to the frame. That's where mine has been for the past 2 years and I haven't had any issues....yet. :wink:
 

KJRR

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I have to say this is probably the most useful post you've made. And you have made quite a few. Useful posts that is.:like:
Having just dealt with having my battery replaced, and the bms, this gives a good understanding of how the system operates.
 

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Great info and video Dave !!! Explains it very well if you take the time to view the entire video. Did not realize how much parasitic draw there was !!!
Just got a nice trickle charger to throw on the Ranger if it sits for more than a few days, and now I know how to hook it up properly. :like:
 


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18 amp draw for a shut down vehicle seems high but would explain a lot. Makes you wonder if a battery maintainer is enough to keep the battery alive. Assuming the screen he was viewing is not something we can see in Forscan?
 

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It also looks like, at least on short trips, the auto stop/start draws a LOT of power from the battery without the system being able to replace it.
Haven't run into that problem cause the stop/start delete button is the first thing I hit after starting.
Even my wife has gotten into the habit of hitting it when she drives it (very very occasionally)
 

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It also looks like, at least on short trips, the auto stop/start draws a LOT of power from the battery without the system being able to replace it.
Haven't run into that problem cause the stop/start delete button is the first thing I hit after starting.
Even my wife has gotten into the habit of hitting it when she drives it (very very occasionally)
Yes I'm sure it takes a lot driving in town. The gas savings from ASS is really just a trade for loss of charge and battery life.
 
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AzScorpion

AzScorpion

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Great info and video Dave !!! Explains it very well if you take the time to view the entire video. Did not realize how much parasitic draw there was !!!

Just got a nice trickle charger to throw on the Ranger if it sits for more than a few days, and now I know how to hook it up properly. :like:
I've been doing that since my original battery died after 18 months. I never knew this about the BMS and this was my first vehicle with this much tech. When I first started using the Ctek it took a good 24+ hours to fully charge. Now it'll recharge a lot quicker (4-6 hours) since I hook it up several days a week.

My Ranger has been parked since Saturday afternoon and I knew I wasn't going to be going out for a few days so I plugged it in. Went out this morning and took it off life support and everything was good. :wink:
 

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I've been doing that since my original battery died after 18 months. I never knew this about the BMS and this was my first vehicle with this much tech. When I first started using the Ctek it took a good 24+ hours to fully charge. Now it'll recharge a lot quicker (4-6 hours) since I hook it up several days a week.

My Ranger has been parked since Saturday afternoon and I knew I wasn't going to be going out for a few days so I plugged it in. Went out this morning and took it off life support and everything was good. :wink:
I picked up a NOCO Genius 10 from Amazon, and is rated for all battery types.
For info, where do you attach your ground to ?
 
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AzScorpion

AzScorpion

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I picked up a NOCO Genius 10 from Amazon, and is rated for all battery types.
For info, where do you attach your ground to ?
Those are really good too. I got mine with my Ford points so it was free. 🤑

I have pictures here where I grounded mine. It's a very tight area and a real PITA to get the bolt out but it can be done....Don't drop it. lol
 

moorejl57

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For those with the CTEK, can I mount the charger in the engine compartment and have the AC plug dangle out the front grill? I have to park outside and don't want the charger in the rain.
 
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AzScorpion

AzScorpion

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For those with the CTEK, can I mount the charger in the engine compartment and have the AC plug dangle out the front grill? I have to park outside and don't want the charger in the rain.
I'm not sure what the heat rating is for it or if it will get damaged from the vibration. Do you have a garage or a porch close by? You could get the longer lead and have that come out the grille and then the charger could be protected undercover and run the extension cord from there.

I ran mine down to the lower front tow hook. This way I can tuck it in the rubber boot when I'm not using it.

https://www.ranger5g.com/forum/threads/fordpass-app-message.20787/#post-447866
 

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Those are really good too. I got mine with my Ford points so it was free. 🤑

I have pictures here where I grounded mine. It's a very tight area and a real PITA to get the bolt out but it can be done....Don't drop it. lol
I think I just saw your dirty underwear🤢

Is that really a pic of under your hood?!
 
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AzScorpion

AzScorpion

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I think I just saw your dirty underwear🤢

Is that really a pic of under your hood?!
I'm still waiting for 303 to come out with an engine cleaner. Being loyal can be tough sometimes. 🤦‍♂️

PS...I don't wear any! :shock::surprised:
 

 
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