Sponsored

Low Battery Voltage on RR AGM 12v Battery ?

ratedz

Member
Joined
Jun 30, 2025
Threads
3
Messages
12
Reaction score
11
Location
GA
Vehicle(s)
25 Ranger Raptor
So I have been monitoring my battery voltage since I noticed that once in a while when I open the doors, all the usual entry lights and screens dont come on. So From what I read online, an AGM 12v battery should be like 12.6 to 12.8 V for a healthy battery. Mine sits around 12.47 after a couple days and after about 4 days it goes way down to 12.01 V. That is way too low. So I brought it to ford and they "checked" it and said it was fine. I told them I dont see how thats possible , but at least I Have registered a complaint about it , so when it does die early hopefully they cover it. I would love for some members to measure their voltage after a few days and post them here so I can see if its just me or its all of us ?

Thanks in advance.
Sponsored

 

hand-filer

Well-Known Member
First Name
Fred
Joined
May 16, 2024
Threads
10
Messages
631
Reaction score
1,013
Location
Manitoba, Canada
Vehicle(s)
2024 Ranger Lariat FX4
I'll disconnect my maintenance charger this evening and provide a follow up mid next week with a voltage reading.
 
OP
OP

ratedz

Member
Joined
Jun 30, 2025
Threads
3
Messages
12
Reaction score
11
Location
GA
Vehicle(s)
25 Ranger Raptor
appreciated
 

stemplar

Well-Known Member
Joined
Sep 7, 2023
Threads
19
Messages
680
Reaction score
959
Location
Pennsylvania
Vehicle(s)
2025 Ranger Lariat 2.7
Mine was weak and borderline since new and I just put an odyssey in it. The cost was below my threshold for spending the time and effort going to the dealer to get another marginal battery. I learned a long time ago not to skimp on snow tires or batteries.
 

Ice.candi

Active Member
Joined
Apr 10, 2024
Threads
1
Messages
30
Reaction score
39
Location
North Carolina, US
Vehicle(s)
2024 Ranger Raptor/2005 Dodge Durango
Mine is pretty much exactly the same as yours and always going into "sleep mode" to preserve battery. Had the dealer test it and they said it was fine and I'd have to leave it for a few days if I wanted it tested for a drain on the battery. I haven't had time for that yet, but it seems like my Battery never goes over about 12.3ish. It's been like that since around November.
 

Sponsored

Hande

Well-Known Member
First Name
Hannu
Joined
Oct 15, 2025
Threads
5
Messages
93
Reaction score
47
Location
Estonia
Vehicle(s)
2025 Ford Ranger Raptor Diesel
Occupation
Business Owner
Exactly like my RR before Ford replaced the battery under warranty.
You need a new battery.
 

patc890

Well-Known Member
First Name
Patrick
Joined
Jun 5, 2024
Threads
6
Messages
182
Reaction score
76
Location
Rockville, MD
Vehicle(s)
2024 Ranger Raptor
Occupation
Retired
So I have been monitoring my battery voltage since I noticed that once in a while when I open the doors, all the usual entry lights and screens dont come on. So From what I read online, an AGM 12v battery should be like 12.6 to 12.8 V for a healthy battery. Mine sits around 12.47 after a couple days and after about 4 days it goes way down to 12.01 V. That is way too low. So I brought it to ford and they "checked" it and said it was fine. I told them I dont see how thats possible , but at least I Have registered a complaint about it , so when it does die early hopefully they cover it. I would love for some members to measure their voltage after a few days and post them here so I can see if its just me or its all of us ?

Thanks in advance.
I got my RR in June 24. I've had battery problems since that. Many times when I just turn the ignition on without starting my battery will read 11.5 Volts but never had a problem starting it. Many times while driving the voltage will read 13 to 13.5 volts. I've had it back to the dealer at least 4 times about this and they never find any problem. They had it for 3 day once to test everything. So I'm living with it but like you said I have registered a complaint.
 

hand-filer

Well-Known Member
First Name
Fred
Joined
May 16, 2024
Threads
10
Messages
631
Reaction score
1,013
Location
Manitoba, Canada
Vehicle(s)
2024 Ranger Lariat FX4
I'll disconnect my maintenance charger this evening and provide a follow up mid next week with a voltage reading.
Here's the update on the battery voltage with the maintenance charger disconnected for 3 days.
The truck is currently in storage. Temperature in the garage is 12C.
March 07, 10:11 PM
Ford Ranger Low Battery Voltage on RR AGM 12v Battery ? 20260307_221122

March 10, 1:56 PM
Ford Ranger Low Battery Voltage on RR AGM 12v Battery ? 20260310_135639


0.01 volt drop.
 

bigb

Well-Known Member
First Name
Brian
Joined
Aug 6, 2025
Threads
57
Messages
700
Reaction score
738
Location
Tucson
Vehicle(s)
2025 Ranger 2.7
So I have been monitoring my battery voltage since I noticed that once in a while when I open the doors, all the usual entry lights and screens dont come on. So From what I read online, an AGM 12v battery should be like 12.6 to 12.8 V for a healthy battery. Mine sits around 12.47 after a couple days and after about 4 days it goes way down to 12.01 V. That is way too low. So I brought it to ford and they "checked" it and said it was fine. I told them I dont see how thats possible , but at least I Have registered a complaint about it , so when it does die early hopefully they cover it. I would love for some members to measure their voltage after a few days and post them here so I can see if its just me or its all of us ?

Thanks in advance.

Are your drive cycles long enough to fully charge the battery? I would start by putting a charger on it for 24 hours (not a trickle charger but a good 6-10 amp charger) so you'll have a starting point. Could be that your battery hasn't been allowed to fully charge and if you are driving short distances and sitting a lot you are losing ground.
 
OP
OP

ratedz

Member
Joined
Jun 30, 2025
Threads
3
Messages
12
Reaction score
11
Location
GA
Vehicle(s)
25 Ranger Raptor
Here's the update on the battery voltage with the maintenance charger disconnected for 3 days.
The truck is currently in storage. Temperature in the garage is 12C.
March 07, 10:11 PM
20260307_221122.webp

March 10, 1:56 PM


0.01 volt drop.
Thanks for the update
 

Sponsored
OP
OP

ratedz

Member
Joined
Jun 30, 2025
Threads
3
Messages
12
Reaction score
11
Location
GA
Vehicle(s)
25 Ranger Raptor
Are your drive cycles long enough to fully charge the battery? I would start by putting a charger on it for 24 hours (not a trickle charger but a good 6-10 amp charger) so you'll have a starting point. Could be that your battery hasn't been allowed to fully charge and if you are driving short distances and sitting a lot you are losing ground.
I put it on an AGM charger till full, took about 6 hours one day, but still no better. It will charge up to 12.8 after a long drive , but if it sits for a few days it drops below where it should be. For now I will just have to live with it and hope it hangs on.

Here is what it looks like since last night... was at 12.81 when i got home its now 12.70 so not too bad after about 12 hrs
Ford Ranger Low Battery Voltage on RR AGM 12v Battery ? 1773243536085-kc
 
Last edited:

TBone4Eva

Well-Known Member
First Name
Tyrone
Joined
Nov 9, 2024
Threads
1
Messages
45
Reaction score
72
Location
Maryland (DC Metro)
Vehicle(s)
2024 Ranger Raptor
Occupation
IT
Here's the update on the battery voltage with the maintenance charger disconnected for 3 days.
The truck is currently in storage. Temperature in the garage is 12C.
March 07, 10:11 PM
20260307_221122.webp

March 10, 1:56 PM
20260310_135639.webp


0.01 volt drop.
Question: How long has your truck been in storage and did you actually turn the truck on at all during the time you monitored the voltage? I ask because after 14 consecutive days of being inactive, the truck puts itself into a deep sleep mode and this would affect your readings and not be as accurate as someone who is driving their truck more regularly.


Why does my Ford vehicle enter Deep Sleep mode?
Deep Sleep mode is designed to conserve your vehicle's battery power. This setting is activated when your vehicle falls under the following conditions:
  • Vehicle inactivity for 14 consecutive days
  • The battery voltage drops below 9.5 volts
  • Extremely cold/hot weather conditions
https://www.ford.com.au/support/how...hy-does-my-ford-vehicle-enter-deep-sleep-mode

I drive very low miles since I commute to the subway station that is only a few miles away to go into DC for work. I know my battery is draining and not getting a full recharge because eventually after about a week or so the auto start/stop will stop functioning (not mad at that, lol). That is usually my clue that it's time to plug it up to a charger.
 
Last edited:

superj

Well-Known Member
First Name
Jason
Joined
Feb 8, 2025
Threads
40
Messages
3,485
Reaction score
3,203
Location
Corpus christi texas
Vehicle(s)
2004 ford ranger, 2024 ford ranger
Occupation
Aircraft examiner
i hooked up the laptop and changed the setting on the battery charge system to 93 or 95% so the truck lets it actually charge the battery fully. i think it was set at something dumb like 80 or 85% from the factory.

mine always seemed to read 11.x when i turn the key to run just to see waht it says. now it says 12.x
 

hand-filer

Well-Known Member
First Name
Fred
Joined
May 16, 2024
Threads
10
Messages
631
Reaction score
1,013
Location
Manitoba, Canada
Vehicle(s)
2024 Ranger Lariat FX4
Question: How long has your truck been in storage and did you actually turn the truck on at all during the time you monitored the voltage? I ask because after 14 consecutive days of being inactive, the truck puts itself into a deep sleep mode and this would affect your readings and not be as accurate as someone who is driving their truck more regularly.


Why does my Ford vehicle enter Deep Sleep mode?
Deep Sleep mode is designed to conserve your vehicle's battery power. This setting is activated when your vehicle falls under the following conditions:
  • Vehicle inactivity for 14 consecutive days
  • The battery voltage drops below 9.5 volts
  • Extremely cold/hot weather conditions
https://www.ford.com.au/support/how...hy-does-my-ford-vehicle-enter-deep-sleep-mode

I drive very low miles since I commute to the subway station that is only a few miles away to go into DC for work. I know my battery is draining and not getting a full recharge because eventually after about a week or so the auto start/stop will stop functioning (not mad at that, lol). That is usually my clue that it's time to plug it up to a charger.
I wake the system up soon after it goes into sleep mode; primarily to be able to monitor the vehicle from the app. I don't start the truck, I just put it in accessory mode for a few seconds to wake up the system. It's a bit annoying that the system isn't able to monitor battery voltage as a determining factor for going into sleep mode.
I agree that my situation is not the same as someone that uses their vehicle on a regular or semi regular basis. If anything, this recent exercise gave me proof that there is no major current draw on the electrical system.
 
Last edited:

dajo

Well-Known Member
First Name
Dave
Joined
Aug 27, 2025
Threads
2
Messages
52
Reaction score
32
Location
Indiana
Vehicle(s)
2025 Ranger Raptor
Occupation
retired
My RR is at home in the garage. Jan 28th connected to trickle charger and went into sleep mode (two Weeks) Feb 11th. March 9th came out of sleep mode and is back on line. Truck has not been touched since Jan 28th. WTH
My 2020 Edge ST will sit all winter with trickle charger on it and never go into sleep mode. Looks like in 2020 there was not the two week requirement.
Sponsored

 
 







Top