Battery voltage driving me crazy

doubletap

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That is normal. May I suggest monitoring a different screen. I like to monitor my gas mileage for some weird reason.
Agreed. Too many people are monitoring their voltage, and are freaking out because they don't understand what's happening. Relax, you're fine. Probably why they deleted Off Road Pages... TMI >>> Obsession Overload. Lol.
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WranglerMan

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Will, you really have to start to listen to your Wife's advice!
Bill,

You are quite correct, maybe I need to buy a Taser JL to give my mind something to do

That is normal. May I suggest monitoring a different screen. I like to monitor my gas mileage for some weird reason.
I look at the mileage as well.


I honestly think my mind goes into overload with all the information we have displayed in these new modern vehicles, things seemed simpler back in the day when you had a CEL indicator and battery and coolant temp analog gage.

Thanks for the replies gents !!!!!!
 

Moto_21

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Does anyone elses voltage read this high with normal driving? I feel like my alternator is pumping out too much. And it never drops below this from start up to shut down. After turning off my battery voltage sits around 12.5. Should i get battery and alternator tested?

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Jkohler

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Mine has been running from 14.3 to 14.7. I’ve even had it in the battery tender.
 

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Does anyone elses voltage read this high with normal driving? I feel like my alternator is pumping out too much. And it never drops below this from start up to shut down. After turning off my battery voltage sits around 12.5. Should i get battery and alternator tested?

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Except for a brief period of about 3 days, mine has been reading that high for several months. The only thing it hurts is lower voltage is supposed to be better for battery life. When I asked the dealer, I was told 14.7 is OK, but above that should be looked at. Mine is now frequently 14.8, so I will be trying to get it into the dealer when convenient.
 

Moto_21

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Except for a brief period of about 3 days, mine has been reading that high for several months. The only thing it hurts is lower voltage is supposed to be better for battery life. When I asked the dealer, I was told 14.7 is OK, but above that should be looked at. Mine is now frequently 14.8, so I will be trying to get it into the dealer when convenient.
Alright at least im not alone lol. Im curious to know what they say when you do take it. I probably wont take mine till its either hard to start or it gets up to 14.8 like yours
 

Greg H

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Mine fluctuates between 14.1 and 14.7. But is usually 14.2 to 14.4. I only drive 7 miles round trip to work each day during the week and around 50 miles over the weekend so I'm not sure if it's driven enough to fully charge.
 
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WranglerMan

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This has been discussed in several posts and in short the voltage is supposed to float from 12.7-14.5 and it can display anything in between, when mine showed 14.5 all the time and ESS did not work as it said battery charging it was due to the main battery going bad but it never failed to start.

My current voltage usually runs 13.5 on startup then after driving for about and hour or so it drops to 12.8 and when I slow down by braking the voltage ramps up over 14 then back down to the 12.8, I very seldomly see above 14 unless I use ESS a lot which my Smart Stop/Start module keeps it off unless I choose to use it
 

Jayjay9228

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This has been discussed in several posts and in short the voltage is supposed to float from 12.7-14.5 and it can display anything in between, when mine showed 14.5 all the time and ESS did not work as it said battery charging it was due to the main battery going bad but it never failed to start.

My current voltage usually runs 13.5 on startup then after driving for about and hour or so it drops to 12.8 and when I slow down by braking the voltage ramps up over 14 then back down to the 12.8, I very seldomly see above 14 unless I use ESS a lot which my Smart Stop/Start module keeps it off unless I choose to use it

So your dealer said that was normal? Because I’m going through that and I have 2 batteries plus that little battery. I’m not use to those readings of 12.7 then going up when I brake. I’m use to running 14.1v on my jku because I have a huge sound system.
 

FirstF80InSpace

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So when I still had the stock batteries, my voltage would constantly be reading between 14.2V and 14.5V. Then after 2 weeks from when I purchased the Jeep, the aux. battery took a dump and I couldn't start the Jeep. I have since replaced the batteries with the Genesis dual battery system, and now my voltage reads between 12.8V and 13.2V.

If I leave the Jeep for a week, it will initially start at 14.2V, but after around 15-20 mins of driving, it drops down to around 13.8V. If I use a battery tender, when I start the Jeep, it runs around 12.9V.
 

moodywizard

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So when I still had the stock batteries, my voltage would constantly be reading between 14.2V and 14.5V. Then after 2 weeks from when I purchased the Jeep, the aux. battery took a dump and I couldn't start the Jeep. I have since replaced the batteries with the Genesis dual battery system, and now my voltage reads between 12.8V and 13.2V.

If I leave the Jeep for a week, it will initially start at 14.2V, but after around 15-20 mins of driving, it drops down to around 13.8V. If I use a battery tender, when I start the Jeep, it runs around 12.9V.

If you have the genesis dual battery system you will want your charging system to stay above the 13.1V threshold so that the 2nd battery charges while running. Just an FYI I also have the genesis dual battery system with a fridge full time etc. I found that by simply disconnecting the IBS sensor on the battery ground cable my alternator voltage is constant 14V+. Might want to go that route if the 2nd battery is not charging sufficiently for you.
 

FirstF80InSpace

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If you have the genesis dual battery system you will want your charging system to stay above the 13.1V threshold so that the 2nd battery charges while running. Just an FYI I also have the genesis dual battery system with a fridge full time etc. I found that by simply disconnecting the IBS sensor on the battery ground cable my alternator voltage is constant 14V+. Might want to go that route if the 2nd battery is not charging sufficiently for you.
Good to know. Thanks!
 

SRQgunner

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As the title states the battery voltage displayed is driving me crazy trying to figure it out, when I first got my JLU a few months ago the voltage displayed would run 12.7-12.9 going down the road with everything on and as I would slow down it would increase and then once stopped and idle it would drop back down to the 12.7-12.9 and I was told this was normal as its designed to charge only when needed but now I am seeing it display 13.7-13.8 all the time except when ESS kicks in at a stop if I forget to turn it off and then once it shuts down at a light with everything on it drops to 12.2-12.3 and once it starts up again it goes back up to the 13.7-13.8.

I have never had any issues starting as in a dead battery and no error messages or warnings displayed so with all my rambling what’s up with it and do I have possible issue.
I have a 2018 Sport. Purchased as certified pre owned in Nov last year with 7k miles.

My volt meter always ran at 14-14.2. On Saturday I had a EVIC message that my aux switches were unavailable as battery was charging. The dealership got me in. Turns out both batteries failed their testing. Both batteries replaced under warranty. After picking the Jeep up the volt meter was again at 14-14.2. Yesterday and today it’s at 12.7-12.9v

was curious as to why the difference from one day to the next. but being both batteries were replaced I assume this is the normal.
 
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ongxaVOTINH

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Which battery is monitor by the odometer screen? Cuzz my jeep won't start and only about 8 voltage.
 

Gee-pah

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Which battery is monitor by the odometer screen? Cuzz my jeep won't start and only about 8 voltage.
Hi David:

In the 3.6L JL, the voltage you see on the odometer screen is best reviewed by pressing the start button twice on a resting jeep, with no foot on the pedal and then examining the voltage with no alternator running. Make sure to press the start button one more time to turn the vehicle off afterwards.

That voltage you see will be, unless you changed the factory wiring, a composite voltage of both batteries.

When the vehicle is on that reading will be those composite voltages along with the alternator; not very reliable.

To get the voltage of only the ESS/Aux battery, remove all cables from the negative post of the main battery and then check the reading when the vehicle is parked as per the procedure above. Make sure to put those cables back on the main battery's negative post when done.

To get the voltage of only the main battery, remove the negative cable on the main battery that is closer to the passenger's side of the vehicle. That is the cable that leads away from the negative post of the ESS/Aux battery. (The other cable is a body ground). Test voltage inside the vehicle and make sure to put that cable back on immediately afterwards.
 
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