2026 1500 Limited 3.0 HO battery not recharging

[HemiSam]

The truck is several months old and has less than 3k miles. I began receiving a message on the dash: Battery Saver on Some Systems May Have Reduced Power. There is also a check engine light on the dash. I borrowed a code reader from AutoZone and P2AF5 (Starter Relay "C" Stuck On) is the only code.

If I pull up the PID's on the dash it shows the battery voltage at 15.X while I'm on the throttle. Drops into the 14's off throttle...looks normal.

I hooked up my Optima smart charger to check the state of the batteries. On the main/large battery it was down to 25% and I charged it overnight...fully charges the main battery, desulfites it...does a nice job on all my vehicles over the years. I hook it up to the small auxiliary battery and it charges and conditions it as well.

The CEL does not go away, but the "Battery Saver" message does go away. Several days later the same message pops up...the battery is not being recharged during operation.

Any thoughts on what is going on? Trying to avoid taking it to the dealer if possible.

HS

 

[jasonw]

From what I read, that code typically means a bad auxiliary battery, which is fairly common on these trucks. A bad one of those can also drain the main battery down. Batteries are such a crap shoot anymore, especially since COVID. Even the really good names are not as reliable as they once were.

If you want to avoid the dealership, you could just replace your batteries with good brand name ones. Worst case, you're preventing a future issue, and you still take the truck to the dealer. Best case, it resolves your issues. Might be doing the "parts cannon" type of thing, but I always replace my OEM batteries after two years or less. Call me paranoid, but I just do not trust them anymore.

 

[mikeru]

It's kind of ironic your username is HemiSam but you bought a Hurricane equipped truck. Perhaps a name change is in order?

You might try load testing both batteries. Pick up an old style "toaster" type battery tester, like this...

https://www.amazon.com/TOPDC-Battery-100-1000-Automotive-Motorcycles/dp/B0DT9MXRR2/ref=sr_1_10?crid=161QL58OYBUII&dib=eyJ2IjoiMSJ9.FYHW5-mp7GmBatbyTIwVWSTu-NOSJJHLv6DXzSe9GF1cagUhTq01F_xW_ONTP3kXlEu7LESFMATTYzi6vJefK7cuKKukHq0F2yZh4L0h6Rq5fdiYXtkpc2FcFD2yQSeCFGc5MZQpjehw1-ZIAPxpKzZUdG8xzQcH-ik5aOtuvqed68DnIvwo15wvEv_hstOdww9qLfuq3sI2zKvs6FD_UvO-3h-OpObZpBs5f-ArO5phzpW-5fEudRDSzbYL-vVJRnKckhFn6-fu3UpIdPOrCWlGy7X9FsTkKpU4P5_HIvE.kn0TmHdyW7JVgTuTQKUGcNOpdEo7AXTq8KnAOzRh_24&dib_tag=se&keywords=battery%2Bload%2Btester&qid=1774819029&sprefix=battery%2Bload%2Btester%2Caps%2C168&sr=8-10&th=1

 

[HemiSam]

@jasonw @mikeru thank you for the responses, gents!

I ordered the old school battery tester. Could likely have borrowed one like that from my father, but a G.A.M. needs his own...LOL.

HS

 

[1999 White C5 Coupe]

I’m not sure why you want to avoid the dealer to diagnose and repair your vehicle under warranty?

Your self-diagnosis and repair may cause other issues, or not resolve your issue. That may open the door for the dealer to refuse to repair your vehicle under warranty.

Another issue is that you may have multiple defects with your vehicle, which could lead to a lemon-law action.

 

[HemiSam]

@1999 White C5 Coupe -thank you for your post.

I own and have owned several modern MOPARs. The dealers near me have proven an awful experience over the years. I try to avoid them when I can, and I enjoy being able to diagnose what is happening so I better understand what is going on.

I will most likely have to take my 26 in for service, but when I do I will be better informed in case they toss the usual BS at me.

HS

 

[HemiSam]

I was able to confirm it is the charging system for the auxiliary battery that is the issue. The auxiliary battery is draining, then it leans on the primary battery, eventually draining it as well.

The first image is with the truck running and putting the charging system under load for a few seconds. Should be 13.5 - 15.X volts and it's just under 11.

The second image is also with the truck running and the tester hooked up to the auxiliary battery, but no load from the tester. The voltage is the same on the auxiliary battery without the truck running / not turned on.

I hope this is of use to someone else.

BIG thank you to the contributors!

HS

 

[HemiSam]

I dropped off my 2026 1500 at a local dealer for the charging issues and a recall on June 23. Long story short, they are replacing both batteries, a pig tail from the PCM and now they are replacing the PCM.

A bit of a run around on when it will be ready, but a call to customer service at least helped with them responding to my questions on when I'll have her back.

The truck has 4 and 5k miles at this point. I wish the JD Power survey had not shown up before the drama...

HS