Watch Your Battery Voltage

[Calm horse]

@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!!!

I've had the sliders for almost 2 years now and notice if I didn't drive for about 4 or 5 days my battery was doing same thing....then about a year ago someone was saying same thing you were and then everyone with the problem all had 1 thing in common...the sliders......I still need to call rse and get whatever it is that helps it...also need to order new passenger side motor

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[ksdon]

I looked at their site and did not readily see anything for the fix so I left them a message on the "ask a question" on one of the pull down.

My sliders are connected so I can remove them from my battery power very easily. I just never though about it before a long trip. Maybe their solution will be even easier.

Wished I'd been born smart and not just so pretty.

 

[Rydfree]

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.

Yes , my 2020 Ranger was the same way if I just drove to work and back during the week. These vehicles have so many things still powered when they are just sitting there that cars of a few years ago didn't have its ridiculous. I've only put 4 batteries in my 1991 Ranger over the years but those days are gone,lol.

 

[gwp]

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.

I’ve already had to have the battery replaced on my 22 2.3L with 24K miles. I typically drive only every other day or so, and very short (1-2 mile) distances unless I’m doing a long road trip. It started with an app error saying I needed to drive more to charge my battery. The error message actually noted I typically drive short distances. I then put some miles on and noticed the gauge stayed at 15V the whole time.

My dealer did a load test and dropped in a new battery. They also noted that the dashboard display reads about .6V higher than actual charging voltage they measured. They updated the digital dash display software. (Yeah, that’s a thing I guess). After update they say it still reads .6V higher than actual.

With the new battery and update, I still usually still see ~15V charge rates. After driving for 30 miles or so it sometimes drops down to 14ish. We’ll see what happens I guess.

I do have a Garmin mini dash cam that typically stays on when I’m parked in the garage for a few days, but the draw is supposed to very low, and it will turn off if it sits too long and battery charge drops. I’m tempted to move that to a switched circuit to see if it helps.

 

[ksdon]

My Ford replacement battery showed it is made in Germany. I could not see very much info on the original factory battery. Other than them being the same ID number (size code) there was not much more. I do not know what brands are made in Germany but hopefully this one will be of good quality. My F150 has a Sears Diehard AGM that is 9 years old. I bought it at a Sears store. It started this last winter on days we stayed below zero.

I am thankful the Bronco's battery died while in the 36 month warranty. And died in the garage instead of on top of some isolated place.

 

[HP11]

I’ve already had to have the battery replaced on my 22 2.3L with 24K miles. I typically drive only every other day or so, and very short (1-2 mile) distances unless I’m doing a long road trip. It started with an app error saying I needed to drive more to charge my battery. The error message actually noted I typically drive short distances. I then put some miles on and noticed the gauge stayed at 15V the whole time.

My dealer did a load test and dropped in a new battery. They also noted that the dashboard display reads about .6V higher than actual charging voltage they measured. They updated the digital dash display software. (Yeah, that’s a thing I guess). After update they say it still reads .6V higher than actual.

With the new battery and update, I still usually still see ~15V charge rates. After driving for 30 miles or so it sometimes drops down to 14ish. We’ll see what happens I guess.

I do have a Garmin mini dash cam that typically stays on when I’m parked in the garage for a few days, but the draw is supposed to very low, and it will turn off if it sits too long and battery charge drops. I’m tempted to move that to a switched circuit to see if it helps.

I also have the dash cam mini and observed the same behavior while connected to the rear passenger side cigarette lighter adapter. Dashcam would remain on for up to 90-minutes after vehicle shutdown and overnight resting battery voltage would drop to 12.3-volts; not ideal resting voltage for an AGM battery that should be around 12.7-volts.

I installed a dual USB port beside the rear passenger side cigarette lighter adapter but tapped into the aux wiring now running off aux switch #6. Because the auxiliary wiring is not powered after vehicle shutdown, dash cam shuts down immediately and I no longer get that drain, albeit minimal, for the 90-minutes after shutdown. If you make many short trips, that 90-minute draw will add up and will negatively affect resting voltage.

 

[JediMcMuffin]

I recently had an issue where the vehicle wouldn’t start despite the voltage being plenty high enough (12.6). The dash would simply reboot the starter would not fire. Ford could not reproduce it and the battery tested clean until they tested it a few times so it did get replaced. The battery issues also revealed some issues with some other module that prevented control of the transfer case. That module (awd) also got replaced.

I will say after all that my voltage while driving went from high 14s to mid 13s and now prior to starting it rests at 12.7.

 

[ksdon]

Rock Slide said they do not have a relay or other fix that will limit battery draw. If Bronco is sitting for 2 weeks plus, they recommend unpluging.

A good battery maintainer, even a more expensive one, is 1/3 or less the cost of a new battery.

 

[Lcubed]

Rock Slide said they do not have a relay or other fix that will limit battery draw. If Bronco is sitting for 2 weeks plus, they recommend unpluging.

A good battery maintainer, even a more expensive one, is 1/3 or less the cost of a new battery.

did they say how much draw to expect for the resting state?

 

[BadmansSAS]

A good 100% charged battery will read 12.6v at rest. The charging system is a smart system and will provide extra voltage to maintain your battery charge as well as supplement voltage as needed as demand goes up. if you are pegged at 14.5+ or more all the time, that means you might have a bad battery and the charging system is compensating.

When its sitting around the mid 13vs then you are good. Thats about normal for electronics on and driving. If voltage from the battery dips, the charging system will ramp up to compensate. At vehicle off, you should see 12.6-12.7. If you see less than that at vehicle off, then you have a bad battery or low battery.

 

[ksdon]

RSE did not say how much draw is on going, but I did not ask.

Most likely their set up is just a contributor to battery drain and not the cause.

 

[cbrenthus]

Rock Slide said they do not have a relay or other fix that will limit battery draw. If Bronco is sitting for 2 weeks plus, they recommend unpluging.

A good battery maintainer, even a more expensive one, is 1/3 or less the cost of a new battery.

What?!?! Why not just pop a relay on the main power that gets its signal from say, a parking light or something that comes on when you open the door?


Also, someone mentioned the alternator is smart and charges more when the battery needs this. I know Jeeps have Intelligent Battery Sensors (IBS) that sense the charge state of the battery and change the voltage of the alternator. You'd see higher voltage when the battery needs to be charged, and lower once it is. I've seen high 14s to mid 12s when driving.

The point of this is that, if the Bronco is the same and I suspect it is, if you are constantly seeing high voltage that means your battery is never reaching a fully charged state, and is probably going to die soon. But who knows, I drove around in my JLUR for something like a year or 2 where Automatic Start Stop (ASS) wouldn't work because "The battery is not fully charged". Then, after a 90 minute each way trip, it worked again for a day or 2. Then, 3 months later it wouldn't start or return my calls then I sweared ^$*# if I find that jeep I'm cutting off..." one morning. Spent something like $250 on a good battery because, even though my Bronco was built, I had no info on when it would ship. Got the call that evening that it was delivered! Oh well, hope the new owner of my JLUR is getting good battery life!


One major not about these electrical systems is that if you have issues with your IBS, it will create issues with your ASS!

 

[Brian_B]

The Bronco does have a battery management system. This video is from an F150, but the Bronco does almost the exact same thing, and does a decent job of talking about how the BMS works for those that are curious.

It tracks all the amps going into and out of the battery, not just voltage -- so be careful when you charge it that you don't go straight on the negative terminal of the battery - that will bypass the BMS and the bronco won't "see" the charge. This is part of how it determines when to disable ASS and when to go into Deep Sleep mode.

Also, lots of short trips - it's very possible that you are overall draining the battery. I don't have a magic number to say what a short trip is versus any other trip, but I know on my WIfe's sport - she mostly runs to kid to the bus stop and back. A couple weeks of that and her Bronco will go into Deep Sleep because a 2 mile trip done frequently isn't enough to put any meaningful charge back into the battery.

The BMS is also part of how the Bronco determines how to run the alternator. It's normal to see periods up around the low 15V's, and it's normal to see voltages in the upper 12V's while out and driving - and everything in between. The Bronco tries to do the bulk of it's charging when it won't pull excess fuel (i.e. coasting, engine braking, etc).

The first sign that your battery is being overly taxed (too many short trips) or getting old and in need of replacement is that ASS will just stop. That is kind of hard to notice though, since it isn't a big red "Check Engine" light or anything. The second is the Deep Sleep notification.

So if you get Deep Sleep - it may just be low and need a bit of help, get your battery fully charged on a maintainer (being mindful the BMS needs to see the amps in). If it keeps doing it - time for a new battery.

 

[Karl_in_Chicago]

One major not about these electrical systems is that if you have issues with your IBS, it will create issues with your ASS!

I suffered from IBS for a brief time and I can say this is absolutely true.

 

[Mattwings]

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.

I have seen my voltage readings elevated for the past few months. I checked it with a meter and OBD2 scanner and found the gauge reads about .5v high. I still think the battery is failing, as it’s a similar condition where the voltage runs consistently high, regardless of time to charge. It’s going in for the rear seal on the transfer case next week and I am going to have the dealer get a look.

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