Watch Your Battery Voltage

[ksdon]

November 21 Bronco went into service, 2.7 engine

Like many on this site I have been receiving Ford Pass notices of Battery Saver Mode etc. This has been going on for many months and I never had trouble starting. Some months ago I noticed that my dashboard Voltage reading was always up in the mid 14. something to 15. something even after all day driving. For those past months I just drove or re-charged with a charger but did NOT keep on a maintainer.

We were going to be gone about 20 days so I fully charged battery before leaving. Returned and on the 22nd day I went out and could not unlock the Bronco with the FOB. Nothing worked...completely dead.

Ford replaced my battery under warranty yesterday. Fully charged the battery and drove around today. From start up until I got home the on dash Volt reading was 13.2 to 13.9. So I am thinking that my continual high voltage reading of past months was a warning that the battery could not be fully charged even after being on a charger and being driven. I will watch my voltage as the new battery ages and I will get a new modern battery maintainer to keep on the battery if not being drive everyday.

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[FleshTuxedo]

Mine is usually at 14.3 and I haven't had an issue yet.

 

[ksdon]

I admit I'm shooting in the dark!!
I do not know that high voltage is a bad thing. It is just that I noticed mine always ran high and never went down even after long charging times. Then after getting a good battery, my voltage gauge shows charging at a much lower voltage.

 

[Ducati1098]

Voltage readings up to ~15.2 can be completely normal depending on certain criteria. Also if you’re going to manually charge your battery, just be sure you’re using an AGM compatible charger otherwise you could damage the battery.

 

[Rydfree]

I put my Bronco on a maintainer when it is going to sit for a couple of days. When I drive after being on the maintainer the voltage gage reads in the 13v range. After a few days of driving to work, which is a short trip, I can see it creeping up into the high 14v range also.

 

[Calm horse]

I admit I'm shooting in the dark!!
I do not know that high voltage is a bad thing. It is just that I noticed mine always ran high and never went down even after long charging times. Then after getting a good battery, my voltage gauge shows charging at a much lower voltage.

Ok...I'm taking a wild guess and you installed rse powered sliders..if I'm right and you did ..this is your problem!...the rse drains the battery ...supposedly they have corrected this problem, but you need to call them for some relay or something...if I'm guessing wrong and you don't have these ill shut my mouth and move on.

 

[Calm horse]

I admit I'm shooting in the dark!!
I do not know that high voltage is a bad thing. It is just that I noticed mine always ran high and never went down even after long charging times. Then after getting a good battery, my voltage gauge shows charging at a much lower voltage.

Ahh yes ....I am right ...i just looked at your profile pick of your bronco!....
If your Bronco sits for a few days without driving you must pull the fuse of the rse sliders...and no you don't just shut the kill swicth off...the board still gets and voltage and drains the battery..

 

[BAUS67]

Ok I'll try to keep this short, kinda hard on this subject. I pay attention to mine as well. My Bronc has set for extended periods of time as well, up to 3 weeks at one time. One note I will make here is do NOT leave the fob in the Bronc while it is not being used, it thinks you are getting ready to start it. It will stay in "ready" mode. if you take the key fob away it will go to sleep. After one of those stints it would be around the 14.7 to 15.2. I started to drive the Bronc everyday for a couple of weeks. It took about a week to get the voltage back down to the 13.2 to 13.6 range. When I say drove it for a week my routine is......

Start the Bronc 10 to 15 mins before I need to leave, helps put a charge in the battery. While I'm in the store, leave the Bronc run. If I go to my cabin, I let it run while there. Sometimes this could be as long as 30 to 45 mins, maybe even an hour. For those that don't know this, about 20 to 30 mins of idle time the Bronc will shut off if you are not paying attention. A prompt will come across the screen. "do you wish to continue to run?". If you do not answer it, it shuts the Bronc off. When idling, it is best to turn off the radio and the heat/ac, unplug your phone, etc, helps put the charge back into the battery instead of running all the accessories.

This is NOT just a problem in the Bronc it is the way ALL new cars are. They have far too many electrical do-dads that take the power made by the alternator and it does not leave anything to "charge" the battery. I see it EVERY day. If you only take short trips it is not enough to put a charge back into the Bronc. If you drive it short trips it needs to run like I described above.


I've seen some others have posted about charging. Just remember cars have a battery sensor on them. Either disconnect the negative battery cable to charge or only hook the red (positive) lead to the battery. The black(negative) lead should go to the frame of the Bronc, NOT the negative of the battery. The sensor cannot "see" the voltage going through the system.


Trying not to get too techy on everyone, my wife hates it and then she doesn't listen. So I'm sure someone will chime in to say that's not right. I'm just trying to speak from experience and to help "dumb it down" so the average Joe can understand. I'm not ASE certified nor am I some super automotive technician, but I do work in a garage and have been in the automotive aftermarket world for over 20 years, I've seen a few things.

I find it funny when customers come in the shop and I explain the above scenario they look at me like I have 4 heads. But then a week or two later that same customer comes back in and says. "I gotta admit I thought you were nuts but DAMN I have not had the issue anymore".



edit: I did not know about the RSE sliders but THAT will definitely cause you problems. Any constant draw is a death nail for a battery.

 

[Shazamalingo]

I put my Bronco on a maintainer when it is going to sit for a couple of days. When I drive after being on the maintainer the voltage gage reads in the 13v range. After a few days of driving to work, which is a short trip, I can see it creeping up into the high 14v range also.

Hmmm…even just for a couple days? Honestly, some of my cars (all 2016 or newer) will sometimes go 1-2 weeks without driving and I’ve not yet had a battery issue. I don’t do anything special as far as I can tell. Heck, our 2016 has an 8 year old original battery in it and I’m just waiting for it to die one day.

 

[Techun]

The alternator is smart and your voltage reading while driving will constantly change.

Usually when accelerating the alternator isn't doing anything. Usually when coasting it is, and V will be 14+.

Just fyi, it's going to bounce around a lot while driving.

 

[BAUS67]

Hmmm…even just for a couple days? Honestly, some of my cars (all 2016 or newer) will sometimes go 1-2 weeks without driving and I’ve not yet had a battery issue. I don’t do anything special as far as I can tell. Heck, our 2016 has an 8 year old original battery in it and I’m just waiting for it to die one day.

When you do drive it you probably drive it a lot, like 20 miles, not just 2 miles and turn it off. Drive time will charge the battery it just takes awhile. I had a 98 Taurus that had a battery that was 15 years old, then I left the lights on one day, It was done. That car did not have the electrical draw that these new ones do. Right now I have an 08 F150 and again, not a lot of draw but that battery is 7/8 years old and no issues and that only gets driven every few weeks as well.

 

[Shazamalingo]

When you do drive it you probably drive it a lot, like 20 miles, not just 2 miles and turn it off. Drive time will charge the battery it just takes awhile. I had a 98 Taurus that had a battery that was 15 years old, then I left the lights on one day, It was done. That car did not have the electrical draw that these new ones do. Right now I have an 08 F150 and again, not a lot of draw but that battery is 7/8 years old and no issues and that only gets driven every few weeks as well.

That’s is true. When I drive them, many times it’s for a half hour. And there are definitely decent road trips thrown in there too…

 

[BAUS67]

That’s is true. When I drive them, many times it’s for a half hour. And there are definitely decent road trips thrown in there too…

It really does make a difference. A good running electrical system helps as well. Just like the RSE steps mentioned here I've seen some wonderous stereo installs that just boggle the mind.


Customer had a Ford Escort. Customers complaint was when driving, at times, the car would hit a bump it would shut off. Turns out it was not the bumps in the road that made it shut off. It was the subwoofer tied into the power wire for the fuel pump. Once that bass hit THUUUUUUUUMP!!! no power to the pump. No lie!!!! people don't think when they do stuff.

 

[Brockdog12]

My 2006 Focus voltage runs from 13.9 to 14.3 typically.

 

[ksdon]

@Calm horse you are very correct about the sliders. To make it worse, I read a post a couple weeks (months?) ago about this drain and completely forgot about!!!
This could be the issue that ended up killing my battery.

Good news is, I am now smarter than I was yesterday!!!!

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