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

Bsthroop

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I have watched this video several times and visited the dealer for a battery health check which tested very good. Thus I am using this charger and considering diconnecting the bms if problematic going forward. https://www.amazon.com/Automotive-Maintainer-Desulfator-Temperature-Compensation/dp/B098JVY4B9/ref=sr_1_4?crid=32N3K53TI9XRA&keywords=6+amp+car+battery+charger&qid=1672758867&s=automotive&sprefix=6+amp+battery+charger,automotive,138&sr=1-4
That charger should work fine, may want to consider one that allows quick connection without opening the hood. If you get Forscan working I would leave BMS working and just up the target %.
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Caliope

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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
Here is how I handled wiring for my trickle charger. Where I park in the garage, I have a hook on the wall to hang the trickle charger on. I was able to pressure fit the SAE connecter in one of the holes in the grill. It has a cover I can snap over it when not in use.

20230116_154541.jpg


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20230116_154512.jpg
 
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AzScorpion

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Here is how I handled wiring for my trickle charger. Where I park in the garage, I have a hook on the wall to hang the trickle charger on. I was able to pressure fit the SAE connecter in one of the holes in the grill. It has a cover I can snap over it when not in use.

20230116_154541.jpg


20230116_154525.jpg


20230116_154512.jpg
That's a great location too! I have to pull all the way forward so I can lower my tailgate. There's not much rom up front so I had to run mine down low by the tow hook for the best and easiest access.
 

Caliope

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That's a great location too! I have to pull all the way forward so I can lower my tailgate. There's not much rom up front so I had to run mine down low by the tow hook for the best and easiest access.
Thanks. Now if I can only find away to install this set up on my '22 Bronco Sport as I am having the same battery issues on it. The grill is not as easy to access from the engine compartment as the Ranger's. I am going to have to really study how that grill and front clip are attached to find a good route and attachment point.
 

gtyates

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It baffles me that many feel there is a need to place a charger on a modern vehicle. Like many have done, I used Forscan to up max charge to 90%. The factory setting of 75% is ridiculous. Since I changed mine I have had zero issues with screens shutting down, proximity sensors not working, and I can go on but you get the picture. On my wife's Explorer, which is a 2017, we recently put battery #3 in it. I also upped the charge percentage on hers from the factory 80% to 90%. Just like I see on my Ranger, we are no longer seeing screen shutdowns, loss of proximity sensors, etc. I have no doubt that Ford set the charge so low to minimize charging, in theory helping fuel mileage. I am seeing the opposite. Since increasing the max charge percentage our fuel mileage has actually improved. Just my $.02 worth. :)
 


Metal Geezer

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Hope someone can clear up my confusion….
It seems you are all charging the primary battery, but isn’t it the aux battery that runs all the background systems when the truck is shut off?
Therefore is it not the aux battery that is being depleted?
IF that is the case and, as the service manual states, the battery isolator disconnects the primary battery when the truck is off, how does charging it resolve the aux battery low voltage issue?
o_O
 

RangerBill

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Hope someone can clear up my confusion….
It seems you are all charging the primary battery, but isn’t it the aux battery that runs all the background systems when the truck is shut off?
Therefore is it not the aux battery that is being depleted?
IF that is the case and, as the service manual states, the battery isolator disconnects the primary battery when the truck is off, how does charging it resolve the aux battery low voltage issue?
o_O
There is no auxiliary battery in US Rangers, at least as standard equipment. Does your truck have one?
 
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SigOris

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Thanks. Now if I can only find away to install this set up on my '22 Bronco Sport as I am having the same battery issues on it. The grill is not as easy to access from the engine compartment as the Ranger's. I am going to have to really study how that grill and front clip are attached to find a good route and attachment point.
On my wife’s BS I ran the leads up the cowl just to the side of wiper. Easy to get the leads there.
 
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AzScorpion

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Hope someone can clear up my confusion….
It seems you are all charging the primary battery, but isn’t it the aux battery that runs all the background systems when the truck is shut off?
Therefore is it not the aux battery that is being depleted?
IF that is the case and, as the service manual states, the battery isolator disconnects the primary battery when the truck is off, how does charging it resolve the aux battery low voltage issue?
o_O
You're probably thinking of the Jeep. They (not all) have an aux battery which runs the A/S/S and what's worse is it controls the main battery. So when that small aux battery dies soon after your main one will. That's why many on the JL forums delete that aux battery.
 

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That would explain a lot. Maybe I should check my service manual version :facepalm:
I have found that even though something is described in the service manual doesn't mean that we have it in the North American Rangers. This is also true of the owner's manual.
 

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True enough. It is a global manual. Good thing I keep checking in here for answers. :)
 

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Thanks. Now if I can only find away to install this set up on my '22 Bronco Sport as I am having the same battery issues on it. The grill is not as easy to access from the engine compartment as the Ranger's. I am going to have to really study how that grill and front clip are attached to find a good route and attachment point.
Here’s a view on our BS. I went with the CTEK charger.

EA72D3CF-7B16-41AD-BE56-64E62D96A7E7.jpeg
 

Caliope

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@SigOris Thanks for the photo. I had thought about that route.
 

SigOris

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@SigOris Thanks for the photo. I had thought about that route.
Truth be told I didn’t look for a grill location as I was afraid of out of sight my wife would drive off without disconnecting ?
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