Battery question

[Lee144]

My truck sat for a few months while I was out of country. the battery was completely dead and needed to be jumped when I picked it up. I put it on the charger and got it from 60% charged to a full charge (according to my charger). I have noticed though when I stop for lights the idle sits around 500rpms and sounds rough. No cels or battery lights or anything just a little rough idle. Today I double checked terminals and grounds and put it back on the charger and it’s back at 60%. I know when I watch the volt gauge on the display it bounces from 12-14 volts but based off of what I’ve read here that can be the alternator or the battery and I think those readings are normal no? I’m goosetuned with stage 2 mods and tcm tune. It’s a 2019 with 30k. No prior issues at this point but I’m leaning towards battery. Am I missing anything?

 

[Stroked out]

Maybe a bms reset would help but yeah probably your battery.

 

[jabroni619]

I don't think the idle is battery related personally. Once the vehicle is on, it's your alternator providing the power. A healthy battery is still important for the voltage regulator to do it's job efficiently, but I don't think a running engine with a 60% battery would affect actual engine performance. I think a more likely cause for that would be old fuel.

 

[W0n70n]

The battery does affect idle if the alternator is being put under a lot of load trying to re-charge the damaged/dead battery so it could cause what you're describing. Being tuned it will more sensitive to old fuel and other gunk that accumulated while you were oconus, I would revert to stock tune if possible, run a few tanks of clean fuel through then change back and see if it's that.

 

[Bracamonte]

My spousal unit borrowed my Raptor for over a week while out of town. Left the lights on entire time and drained the battery. I reset electronics (which had crapped out due to truck trying to cut off everything to get a cycle to start) by pulling the terminals off the battery and letting it sit for over 10 mins. Once reconnected, it started idling rough. Also rode a little rough at first. These trucks are so electronic-heavy, it controls everything. You need to drive the truck for a bit and see if it adjusts the idle/trim levels. Stuff will start coming back. Also needs to keep a good charge overnight while not been driven. If you can't nurse that battery back to health with the charger, time for a new one, or you will keep going through this repeatedly.