[RxSummit16]

Control module voltage (V) = 14.388
Input voltage read by the scan tool (V) = 15 - 15.2

I just noticed that the voltage reading on the dash was staying a little high so I logged some info through the ODB and got the above readings. These were steady after about 4 minutes of driving and didn't change until I parked.

Something to be concerned about?

[arpad_m]

TL;DR: no, it's most likely not a problem.

The charging system uses different voltage levels depending on the state and condition of the battery, and as long as the voltage drops after an amount of normal driving, everything is fine. The gauge automatically displays the system voltage that fluctuates between 12.5V and 15.5V.

Neither a short trip nor idling the engine is enough to properly charge the battery, you need to drive the car a while for the battery to be completely charged and the associated state to kick in; see full details below.

[RxSummit16]

Thanks! I haven't been driving often or far because I've been working from home. I think I just noticed it because I had an unrelated CEL recently and have been hypervigilant about the gauges...

[ember1205]

As mentioned, "after a normal amount of driving" the readings should drop off. 4 minutes is generally nowhere near long enough to fit that description, though.

Given that your car is 4 years or so old, it's possible that the battery is starting to show its age. While I wouldn't be worried about it, I would try and make it a point to notice where that gauge is at various times to see if it's trending towards staying at the higher voltage output areas. You could also try connecting a tender and seeing what happens with that, too.

[RxSummit16]

Took it out today, drove for about 15 min. Once it got up to around 15..it stayed there until I turned off the car. Should it have been coming down in that time frame..or does it still need longer?

[parish8]

I say stop looking at the gauge unless you have a problem. When it reads low it kinda drives me nuts

[indyz]

Originally Posted by RxSummit16

Took it out today, drove for about 15 min. Once it got up to around 15..it stayed there until I turned off the car. Should it have been coming down in that time frame..or does it still need longer?

I do a lot of short trips, running errands. Sometimes I go days without driving the car.

I see the voltage at 14.5 after such instances, and after a nice long cruise (25 min+), it will drop back to the 12.5 range.

I know heat soak is an issue but it only affects me when I haven't driven for many days and then do multiple stops and starts, while running errands. If I get the voltage readout to the 12.5 range, I never experience the "heat soak" weak start.

Just go for a nice long cruise.... enjoy the car.

Or get a battery tender.

[Jeb114]

Its an Intelligent charging system. Adjusts as needed.

[ember1205]

Originally Posted by RxSummit16

Took it out today, drove for about 15 min. Once it got up to around 15..it stayed there until I turned off the car. Should it have been coming down in that time frame..or does it still need longer?

I've had mine drop down to 12.5 right after starting it up and I've also had it float around 14.5 - 15 for what I felt were lengthy periods of time. If you do a lot of short trip stuff, it's feasible that it will need to stay on the higher side for charging more. Try connecting a tender to see how long it takes to top the battery off. It should fully recover on a 1.5A charger/tender in a few hours or so.

Once it's topped off, see if taking it out for a longer drive (I'd say at least 20 minutes) allows the charging system to top the battery back off so the charge voltage drops back down. If it doesn't drop after driving it that long, try shutting it off and restarting it a minute later to see if there's a change. The charging system on these cars is fairly complex, and I personally don't know if that gauge is reading voltage at the alternator (which could be charging the battery as well as driving components), at the battery, or somewhere else in the system.