Resting Battery voltage high -- 12.89V

sajohnson

Badlands
Well-Known Member
Joined
Dec 1, 2021
Threads
17
Messages
1,199
Reaction score
989
Location
MIDDLETOWN, MD
Vehicle(s)
'22 Badlands ordered 12/17/2021 - Arrived 3/25/22
Just curious -- most 12 volt flooded lead-acid batteries settle around 12.67 to 12.70 volts a couple hours after being fully charged.

Has anyone else measured close to 12.9 volts -- after the battery has been off the charger for a few hours?

BTW, that 12.89V was 2 days after disconnecting the Battery Tender.

I've also seen the opposite. After driving the BL several miles -- highway, start/stop turned off -- the next day the voltage was 12.30V. I've seen that a couple times also.

I'm wondering what others have measured.
Sponsored

 

magicbus

Badlands
Well-Known Member
Joined
Aug 11, 2020
Threads
16
Messages
723
Reaction score
1,129
Location
Nantucket
Vehicle(s)
BS BL+BL, Rivian R1T, Sprinter 3500 camper
Never noticed high voltage , but after a week of all short trips I get the “remote features disabled” message on my phone due to low voltage. As I recall, when I had a charger on the battery I noticed a 5 amp draw just opening the door that dropped to 3 for minutes. That’s a pretty good draw from opening the door.
 
OP
OP
sajohnson

sajohnson

Badlands
Well-Known Member
Joined
Dec 1, 2021
Threads
17
Messages
1,199
Reaction score
989
Location
MIDDLETOWN, MD
Vehicle(s)
'22 Badlands ordered 12/17/2021 - Arrived 3/25/22
Never noticed high voltage , but after a week of all short trips I get the “remote features disabled” message on my phone due to low voltage. As I recall, when I had a charger on the battery I noticed a 5 amp draw just opening the door that dropped to 3 for minutes. That’s a pretty good draw from opening the door.
Thanks magicbus, that's helpful.

I took the BL off the Battery Tender last night and then made the 'mistake' of opening the door.

I didn't measure the draw, but I'll check the voltage later.

It seems to either be high -- >12.85V -- or low -- <12.35V. I've never seen ~12.7V.

I know that sometimes even relatively new batteries can have reduced capacity. Just sitting on a shelf there is 'self-discharge' -- especially at higher temperatures. When installed in a vehicle, there is always some parasitic draw.

In older vehicles that is usually just a few mA. The BS seems to be in a whole other category.

My concern is that after leaving the factory, the door(s) are obviously opened and closed at least a few times; the engine is started but only run briefly (so the battery does not get fully recharged) -- then it sits on a train for weeks.

By the time we take delivery, the battery may have already lost capacity. Of course it will almost certainly outlast the warranty.

I'm used to factory batteries lasting longer than the ~5 year average. The battery in our Sprinter van lasted 10 years and was still testing OK. It will be interesting to see how much life BS owners get from the OE battery.
 

Osco

Banned
Base
Banned
First Name
Marty
Joined
Dec 19, 2020
Threads
31
Messages
1,805
Reaction score
3,121
Location
North Carolina
Vehicle(s)
2021 Ford Bronco Sport and 2004 Ford Escape AWD
FWIW,
My 2021 BS Base with 27,000 miles spread over 27 months of ownership.
OEM Battery after a 24 hour sit in 55 degree F weather showed with the headlight Fans RUNNING during the test mind you.
Because I unlocked the door to get at the hood latch,,,
Showed 12.11 VDC
I came back 10 minutes later and the fans were OFF.
I got 12.43 VDC.
To compare:
My 2004 Ford Escape with a four and a half year (54month old) interstate battery at rest showed me 12.11 Volts.
Just useless data right !
 

Osco

Banned
Base
Banned
First Name
Marty
Joined
Dec 19, 2020
Threads
31
Messages
1,805
Reaction score
3,121
Location
North Carolina
Vehicle(s)
2021 Ford Bronco Sport and 2004 Ford Escape AWD
I must Add: my interstate battery that’s @ 12.1 VDC starts my 04’ V-6 3.0L Escape like a new battery. Spins it real fast.
 


OP
OP
sajohnson

sajohnson

Badlands
Well-Known Member
Joined
Dec 1, 2021
Threads
17
Messages
1,199
Reaction score
989
Location
MIDDLETOWN, MD
Vehicle(s)
'22 Badlands ordered 12/17/2021 - Arrived 3/25/22
FWIW,
My 2021 BS Base with 27,000 miles spread over 27 months of ownership.
OEM Battery after a 24 hour sit in 55 degree F weather showed with the headlight Fans RUNNING during the test mind you.
Because I unlocked the door to get at the hood latch,,,
Showed 12.11 VDC
I came back 10 minutes later and the fans were OFF.
I got 12.43 VDC.
To compare:
My 2004 Ford Escape with a four and a half year (54month old) interstate battery at rest showed me 12.11 Volts.
Just useless data right !
Thanks Osco, those seem like ballpark figures.

12.43V after 10 minutes seems OK, but what I noticed is that hours later, after leaving the hood open (or unlatched) so I do not have to open the driver's door -- the voltage is still very low. Unless significantly discharged, the batteries in all of our other vehicles will 'bounce back' to about 12.65-12.7 volts after sitting for a couple hours with no load on them.

My wife put about 80-90 highway miles on the BS yesterday. Currently it's sitting with the hood latched. Since I first noticed the low voltage of the BS BL battery, I've been putting a Battery Tender on it and leaving the hood unlatched. I'll check it in a little while. It should be fully charged after being driven so far. I'll measure the voltage after opening the door (which I expect to be relatively low) and then wait a couple hours and check it again. My guess is that it will still be low (it has been in the past) and if so, I'll put the BT on it.

When I see that a battery does not bounce back to at least ~12.65V after a relative small, short duration load (like opening the door on the BS) I suspect it is getting weak. A brand new battery should not end up at just 12.3 to 12.4V (1-2 hours after a modest load, starting fully charged). It is an indication that the battery was left at a partially discharged state for a significant period of time before the vehicle was delivered.
 

Osco

Banned
Base
Banned
First Name
Marty
Joined
Dec 19, 2020
Threads
31
Messages
1,805
Reaction score
3,121
Location
North Carolina
Vehicle(s)
2021 Ford Bronco Sport and 2004 Ford Escape AWD
FWIW I drove 19 miles to day, three stops, all under fifteen minutes.
Got home, popped the hood. Came back when those stupid head light fans were off.
12.43 vdc
 
OP
OP
sajohnson

sajohnson

Badlands
Well-Known Member
Joined
Dec 1, 2021
Threads
17
Messages
1,199
Reaction score
989
Location
MIDDLETOWN, MD
Vehicle(s)
'22 Badlands ordered 12/17/2021 - Arrived 3/25/22
I must Add: my interstate battery that’s @ 12.1 VDC starts my 04’ V-6 3.0L Escape like a new battery. Spins it real fast.
Yep, that's not surprising. 12.1V is about a 50% charge ("SOC"). Check out this chart:

Ford Bronco Sport Resting Battery voltage high -- 12.89V 1667158100243


My concern is not that the battery will not start the BL, but that its life has been shortened. It may need to be replaced sooner than normal (but outside Ford's warranty).

If that's the case, it isn't the end of the world -- but it's reasonable to expect a new vehicle to have a battery that is in like-new condition.
 
OP
OP
sajohnson

sajohnson

Badlands
Well-Known Member
Joined
Dec 1, 2021
Threads
17
Messages
1,199
Reaction score
989
Location
MIDDLETOWN, MD
Vehicle(s)
'22 Badlands ordered 12/17/2021 - Arrived 3/25/22
FWIW I drove 19 miles to day, three stops, all under fifteen minutes.
Got home, popped the hood. Came back when those stupid head light fans were off.
12.43 vdc
There are a lot of variables, so it's difficult to say with any certainty, but 12.43V might be OK a few minutes after those fans turn off. Hopefully the voltage was still increasing. What's best is to measure the "resting" voltage -- leave the hood open/unlatched (so you don't have to open the door) and re-check the voltage after an hour or two. Then it should be at least 12.65V (dep on temp).

I imagine some people reading our posts are thinking that 12.43V is pretty close to 12.6-12.7V, but the fact is the difference between a fully charged battery (100% SOC) and one that's only half charged is just over half a volt.

If a fully charged battery does not 'rebound' to its original voltage after having a modest load applied for a short time, it is on it's way out.
 

Osco

Banned
Base
Banned
First Name
Marty
Joined
Dec 19, 2020
Threads
31
Messages
1,805
Reaction score
3,121
Location
North Carolina
Vehicle(s)
2021 Ford Bronco Sport and 2004 Ford Escape AWD
Yep, that's not surprising. 12.1V is about a 50% charge ("SOC"). Check out this chart:

Ford Bronco Sport Resting Battery voltage high -- 12.89V 1667158100243


My concern is not that the battery will not start the BL, but that its life has been shortened. It may need to be replaced sooner than normal (but outside Ford's warranty).

If that's the case, it isn't the end of the world -- but it's reasonable to expect a new vehicle to have a battery that is in like-new condition.
Ill give the benefit of doubt to Ford and assume the OEM spec is a 48 month battery. Mine is now two years old so it’s half way done right ?
But what about all these modern bells and whistles eating up our batteries.
LED head lamp cooling fans that turn on when you unlock a door and the headlights have been off for 24 hours ? Cold as they can be.
Ford. Your better than that .
I expect my OEM Battery will get me past my 36 month warranty so no complaints here.
AGM type goes in next.
 


OP
OP
sajohnson

sajohnson

Badlands
Well-Known Member
Joined
Dec 1, 2021
Threads
17
Messages
1,199
Reaction score
989
Location
MIDDLETOWN, MD
Vehicle(s)
'22 Badlands ordered 12/17/2021 - Arrived 3/25/22
Ill give the benefit of doubt to Ford and assume the OEM spec is a 48 month battery. Mine is now two years old so it’s half way done right ?
But what about all these modern bells and whistles eating up our batteries.
LED head lamp cooling fans that turn on when you unlock a door and the headlights have been off for 24 hours ? Cold as they can be.
Ford. Your better than that .
I expect my OEM Battery will get me past my 36 month warranty so no complaints here.
AGM type goes in next.
AGM is a good choice. They typically cost more but last longer. The Sprinter battery I mentioned in post #3 was AGM, as is its replacement. It was 10 years old and still working OK. I probably didn't have to replace it, but tests were inconclusive and I figured we'd gotten our money's worth from it.

We've only had our BL about 7 months, so the battery should be performing well. As it happens, when I checked it earlier it was 12.35V. That was after a long highway drive yesterday but of course I had to open the door to unlatch the hood, which causes some stuff to turn on -- like the LED head lamp cooling fans you mentioned. After waiting about an hour, the voltage had gone up to 12.75V. So maybe it is OK.

When I measured almost 12.9V at rest (see OP) I thought perhaps Ford had installed an AGM battery. Somewhere I saw that there is an optional AGM for the BS. I checked the P/N on our battery but it is the ordinary flooded lead-acid (FLA). So I can't explain the high voltage I saw -- that was really strange. It was 2 days after disconnecting the charger -- not 20 minutes. I've never seen that before.
 
OP
OP
sajohnson

sajohnson

Badlands
Well-Known Member
Joined
Dec 1, 2021
Threads
17
Messages
1,199
Reaction score
989
Location
MIDDLETOWN, MD
Vehicle(s)
'22 Badlands ordered 12/17/2021 - Arrived 3/25/22
Follow-up to post #11:

I had left the hood unlatched so I would not have to open the door, and when I checked a little while ago (2 days later) the voltage had settled at 12.65V, which is normal.

I'm still curious about the 12.9V I measured -- 2 days after disconnecting the charger (see the OP).

BTW -- I just looked through all of my BS bookmarks (over 100) and could not find the battery info. I know I saw it in some Ford materials. It mentioned the standard FLA battery and the AGM. The part numbers were very similar. It bugs me that I can't find it, but in any case, an AGM battery is available, when the time come to replace the OE battery.
 

Glamdring70

Badlands
Well-Known Member
First Name
Tim
Joined
Mar 26, 2021
Threads
18
Messages
1,223
Reaction score
1,910
Location
Oregon
Vehicle(s)
'21 BL+BL
BTW -- I just looked through all of my BS bookmarks (over 100) and could not find the battery info. I know I saw it in some Ford materials. It mentioned the standard FLA battery and the AGM. The part numbers were very similar. It bugs me that I can't find it, but in any case, an AGM battery is available, when the time come to replace the OE battery.
Not 100% sure these are the right numbers, but here's what came up the last time I searched Ford for a replacement battery for BS.
https://www.broncosportforum.com/forum/threads/battery-replaced-after-3-months.5395/post-98872
 
OP
OP
sajohnson

sajohnson

Badlands
Well-Known Member
Joined
Dec 1, 2021
Threads
17
Messages
1,199
Reaction score
989
Location
MIDDLETOWN, MD
Vehicle(s)
'22 Badlands ordered 12/17/2021 - Arrived 3/25/22
Not 100% sure these are the right numbers, but here's what came up the last time I searched Ford for a replacement battery for BS.
https://www.broncosportforum.com/forum/threads/battery-replaced-after-3-months.5395/post-98872
Good info there, thank you!

I went ahead and posted on that thread also. I can't see any reason to get the ordinary FLA battery instead of the AGM. AGM has several advantages and is $25 LESS (MSRP).

One thing to keep in mind -- while AGM is better than FLA, generally speaking -- I suppose it's possible to have an incredibly high quality FLA that's better than a cheap, made in China, AGM. IDK.

Lifeline AGMs were designed for tanks and fighter jets (etc.) but as with other products, I'm sure it's possible to cut corners with AGM manufacturing, so before buying an AGM (or any battery) from an unknown mfr, I'd want to check around and get some feedback.
Sponsored

 
 




Top