Battery Voltage creeps up on long trip

[AustinKalb]

I’m driving from SoCal to Alaska solo so I have a lot of time to stare at gauges (maybe too much time).

It’s a diesel with the tow option including the heavy duty alternator. In back I have a couple 1000aHr batteries running a flat mounted starlink while I’m driving. The battery manager is part of the RedArc RedVision box. Oh there is solar also atop the Alucab.

My battery voltage gauge is at around 13.5 v after starting and slowly during my drive it creeps up to 14.6-14.7. For clarity I mean each start. It does that every time. AI says below 15 is pretty normal.

Should I be worried?

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[ShadowsPapa]

I’m driving from SoCal to Alaska solo so I have a lot of time to stare at gauges (maybe too much time).

It’s a diesel with the tow option including the heavy duty alternator. In back I have a couple 1000aHr batteries running a flat mounted starlink while I’m driving. The battery manager is part of the RedArc RedVision box. Oh there is solar also atop the Alucab.

My battery voltage gauge is at around 13.5 v after starting and slowly during my drive it creeps up to 14.6-14.7. For clarity I mean each start. It does that every time. AI says below 15 is pretty normal.

Should I be worried?

Ignore AI on stuff like this. It's pulling from forums and fakebook and other places and is too generic.

Depending on your equipment and how things are wired and configured, it could be causing a problem.

NORMAL is for the voltage to drop on LONG drives, say, over an hour, IF your batteries (main and aux) are fully charged.
Higher voltage means it's seeing the batteries need a charge.
Not knowing how you have things wired it, it's really hard to say what's going on. I can only speak to a stock, normal system.
For example, if the stock truck batteries are fully charged, on a long drive, I've seen voltage drop to 12.6 heading back from Colorado Springs to Iowa.
Mine drops to the low 13s otherwise after some drive time.
If your truck's two batteries are fully charged and IN GOOD CONDITION, voltage that high could heat and overcharge them.

How do you have your other things tied in? Are you connecting the ground for your other stuff at the top of the IBS?
Never connect anything below the IBS directly to the battery's negative post, aways to the studs on top.

 

[AustinKalb]

There is a single wire powering the RedArc directly from the plus battery terminal. I’m pretty sure everything is grounded to chassis ground, I’ll check. I guess I could pull the marine fuse to the RedArc to take that out of the equation (it can run on its own solar).

Also I failed to mention a garmin power switch as well as some factory installed lights connected through the Aux Switches. Factory winch. CB direct to battery. CB linear direct to battery. Also an electric PTO for a compressor. If I think for a while, there’s maybe more.

There’s a lot going on and plenty of opportunities for miswiring. The truck is 2.5 years old and after the battery died once it stays on a battery maintainer.

 

[ShadowsPapa]

There is a single wire powering the RedArc directly from the plus battery terminal. I’m pretty sure everything is grounded to chassis ground, I’ll check. I guess I could pull the marine fuse to the RedArc to take that out of the equation (it can run on its own solar).

Also I failed to mention a garmin power switch as well as some factory installed lights connected through the Aux Switches. Factory winch. CB direct to battery. CB linear direct to battery. Also an electric PTO for a compressor. If I think for a while, there’s maybe more.

There’s a lot going on and plenty of opportunities for miswiring. The truck is 2.5 years old and after the battery died once it stays on a battery maintainer.

If you aren't using the ground points on the right fender area, or other Jeep ground points, make sure you ground to the top of the IBS - the top of this -
Otherwise, use of the ground studs is fine for most things that don't require massive amperage.

You mentioned a great troubleshooting step - take something out of the equation and see what happens. Process of elimination. Could be you have another issue, but you have the right idea, IMO.

 

[Hunter#1]

Mine starts at 14.5 when first started, then as I make my stops it drops to 14.4 then next stop 14.2 . I took it to the dealer for a battery check, I left the Glad overnight for them, they said the batteries are good and charging properly. They fixed some other things also. I feel they may be BSing me. Truck starts good, winter time it may drop to 13.5 in real cold weather. I'm picking up a charger today. I can't use a bettery tender because I can't leave it pluged in overnight.

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