Battery issue common 2026 still?

[Rwfish]

I have a 2026 with 1900 miles. Having the battery drain issues. Dealer keeps telling me I'm not driving far enough to charge the batteries, which I have a hard time believing. 4-5 days a week i drive 10 miles one way, 5-6 is on highway, then home. Once a week I drive 16 miles one way all highway. I bought a noco genius 10amp tender. Have charged the truck several times for almost 24 hrs. Unplug charger, get in truck the next morning, batteries down to 12.1-11.3 range. I've read everything from low quality batteries from factory, to the recalled trailer light/brake wiring causing it, (dealer has ordered the recall part) as well as the key fob being too close,( stored about 25ft away)as well as the ram app causing it(uninstalled from phone). As well as various other theories. Seems like ram/stellantis doesn't have a fix for this and are beating around the bush. I really like this truck other than the battery issue. I realize these rigs have a ton of electronics, but my 07.5 never had issues with the mileage I drive, only bought a new truck because that truck had accelerator pedal position sensor issues, took it in multiple times to a shop, then the dealer, couldn't find an answer, until I took it to a different shop and he found the problem after a couple hours and bought the truck from me. Sighhhhhhhh....

 

[Adub]

That volt range is indicative of failing battery. I’d replace, or have them replace if they will, and you should be gtg.

 

[rpr]

I have a 2026 with 1900 miles. Having the battery drain issues. Dealer keeps telling me I'm not driving far enough to charge the batteries, which I have a hard time believing. 4-5 days a week i drive 10 miles one way, 5-6 is on highway, then home. Once a week I drive 16 miles one way all highway. I bought a noco genius 10amp tender. Have charged the truck several times for almost 24 hrs. Unplug charger, get in truck the next morning, batteries down to 12.1-11.3 range. I've read everything from low quality batteries from factory, to the recalled trailer light/brake wiring causing it, (dealer has ordered the recall part) as well as the key fob being too close,( stored about 25ft away)as well as the ram app causing it(uninstalled from phone). As well as various other theories. Seems like ram/stellantis doesn't have a fix for this and are beating around the bush. I really like this truck other than the battery issue. I realize these rigs have a ton of electronics, but my 07.5 never had issues with the mileage I drive, only bought a new truck because that truck had accelerator pedal position sensor issues, took it in multiple times to a shop, then the dealer, couldn't find an answer, until I took it to a different shop and he found the problem after a couple hours and bought the truck from me. Sighhhhhhhh....

Measure the battery voltages of each battery with a multimeter after you start it. They both should show ~13.6V. If either is significantly lower than that then that battery(ies) is not getting a charge from the alternator, likely due to a relay stuck open in the PCM. I’m betting your main battery is not charging but your Aux battery is. That will result in both batteries getting discharged.

That’s the issue I’m currently having. I had to run a battery cable from the Aux positive to the Main positive so they both get a charge. That temp fix has been working for me for the past week until I get back in town and my dealer can get me in.

If both batteries show ~13.6V with the truck running, then it might just be bad batteries.

Good luck.

 

[Rwfish]

Measure the battery voltages of each battery with a multimeter after you start it. They both should show ~13.6V. If either is significantly lower than that then that battery(ies) is not getting a charge from the alternator, likely due to a relay stuck open in the PCM. I’m betting your main battery is not charging but your Aux battery is. That will result in both batteries getting discharged.

That’s the issue I’m currently having. I had to run a battery cable from the Aux positive to the Main positive so they both get a charge. That temp fix has been working for me for the past week until I get back in town and my dealer can get me in.

If both batteries show ~13.6V with the truck running, then it might just be bad batteries.

Good luck.

I've yet to test them with a meter. The dealer charged and tested them and said they were good. After I start the truck, they charge up to 14.2-14.5 according to the trucks battery level screen, not sure how accurate it is though. Which battery is considered the aux and which is the main? Thanks

 

[rpr]

The aux is the smaller one

 

[Rwfish]

The aux is the smaller one

I guess I assumed they were both the same size like my last truck

 

[eltaco]

This also weighed on me as I went forward with my 2025 purchase. I do travel quite a bit with mine and sometimes well off of the beaten path. At the time I purchased, battery issues were very prevalent.

I just rolled past 20k miles and haven’t had a battery related issue yet on my 2025. From what I’ve seen, it’s specific to the individual vehicle. Some 25s and 26s had the issue… some are bad batteries and others are parasitic drains. You really won’t know until you roll the dice.

 

[John-117]

I have a 2026 with 1900 miles. Having the battery drain issues. Dealer keeps telling me I'm not driving far enough to charge the batteries, which I have a hard time believing. 4-5 days a week i drive 10 miles one way, 5-6 is on highway, then home. Once a week I drive 16 miles one way all highway. I bought a noco genius 10amp tender. Have charged the truck several times for almost 24 hrs. Unplug charger, get in truck the next morning, batteries down to 12.1-11.3 range. I've read everything from low quality batteries from factory, to the recalled trailer light/brake wiring causing it, (dealer has ordered the recall part) as well as the key fob being too close,( stored about 25ft away)as well as the ram app causing it(uninstalled from phone). As well as various other theories. Seems like ram/stellantis doesn't have a fix for this and are beating around the bush. I really like this truck other than the battery issue. I realize these rigs have a ton of electronics, but my 07.5 never had issues with the mileage I drive, only bought a new truck because that truck had accelerator pedal position sensor issues, took it in multiple times to a shop, then the dealer, couldn't find an answer, until I took it to a different shop and he found the problem after a couple hours and bought the truck from me. Sighhhhhhhh....

Have the dealer replace both batteries. Change the sensitivity to the lowest settings so the key fob is not turning on lights and unlocking when you get close. Set it so you have to grab the door handle to unlock the truck. Have everything shut off immediately after shutting truck off.

 

[John-117]

I have a 2026 with 1900 miles. Having the battery drain issues. Dealer keeps telling me I'm not driving far enough to charge the batteries, which I have a hard time believing. 4-5 days a week i drive 10 miles one way, 5-6 is on highway, then home. Once a week I drive 16 miles one way all highway. I bought a noco genius 10amp tender. Have charged the truck several times for almost 24 hrs. Unplug charger, get in truck the next morning, batteries down to 12.1-11.3 range. I've read everything from low quality batteries from factory, to the recalled trailer light/brake wiring causing it, (dealer has ordered the recall part) as well as the key fob being too close,( stored about 25ft away)as well as the ram app causing it(uninstalled from phone). As well as various other theories. Seems like ram/stellantis doesn't have a fix for this and are beating around the bush. I really like this truck other than the battery issue. I realize these rigs have a ton of electronics, but my 07.5 never had issues with the mileage I drive, only bought a new truck because that truck had accelerator pedal position sensor issues, took it in multiple times to a shop, then the dealer, couldn't find an answer, until I took it to a different shop and he found the problem after a couple hours and bought the truck from me. Sighhhhhhhh....

It may also be what one of fellow members calls a parasitic draw/ drain that is causing the problem. The point is to not accept the dealer trying to tell you you are not driving enough!

 

[StuntRDRHO]

Anyone have recommendations if we were to replace our stock batteries? Would you need to replace both?

I replaced my main with a FVP 94 main and new aux haven’t had any issues since

 

[lazerbeak]

Are you guys just skipping the dealership to replace main & aux batteries with higher-quality units?

Makes sense. I guess if the dealer will only reinstall another OEM battery(ies) that will again fail in time, the problem is not solved.

I'd rather fix it & have some peace of mind rather than just kick the can down the road...

 

[lazerbeak]

Measure the battery voltages of each battery with a multimeter after you start it. They both should show ~13.6V. If either is significantly lower than that then that battery(ies) is not getting a charge from the alternator, likely due to a relay stuck open in the PCM. I’m betting your main battery is not charging but your Aux battery is. That will result in both batteries getting discharged.

That’s the issue I’m currently having. I had to run a battery cable from the Aux positive to the Main positive so they both get a charge. That temp fix has been working for me for the past week until I get back in town and my dealer can get me in.

If both batteries show ~13.6V with the truck running, then it might just be bad batteries.

Good luck.

Any resolution to your issue yet? Just wanted to follow up since it seems I may be having the same problem...

Thanks for sharing your experience & info! Your posts are why forums are such a valuable resource!

 

[John-117]

Are you guys just skipping the dealership to replace main & aux batteries with higher-quality units?

Makes sense. I guess if the dealer will only reinstall another OEM battery(ies) that will again fail in time, the problem is not solved.

I'd rather fix it & have some peace of mind rather than just kick the can down the road...

I can go either way on this. I replaced with factory batteries under warranty. I was skeptical that my truck was finally fixed but so far so good. I decided to 1st give the dealership a chance to fix the problem. I can certainly see fellow members replacing their batteries with better AGM batteries out of convenience coupled with the OEM batteries rep.

 

[lazerbeak]

I agree.

I will give my local dealership a chance to fix it.

If it is an underlying code/battery not being charged, no need on spending ~$500 of my own money on better batteries just to have them die as well in a year or so.

Not sure if a better battery would charge better than OEM part/s - not sure how that works, I'm not an engineer!

Hoping for the best! RHO is a great truck, in the end I think I'd rather have this issue than something I'd have no chance of addressing myself. We shall see...

 

[RHODRIVER]

Looked under the hood of my truck, which was built less than a month ago. How long have the rho’s been coming with agm batteries?

 

[ROCKO]

Looking at the 2026 rho, seeing all these common battery drain issues. Is it still common in the 2026 like the 2025 models? Is the fix as simple as turning off proximity and keeping the fob and card in a faraday bag? Or is it more complex?

I would not stress to much my truck’s previous owner had the battery swapped and I’ve never had issues in that area knocking on wood!!!

 

[rpr]

Any resolution to your issue yet? Just wanted to follow up since it seems I may be having the same problem...

Since this thread was resurrected I noticed I never replied to the above. In my case it was a blown 150A fuse array that sits under the PDC. Apparently the only thing that 150A fuse affects is the charging circuit from the alternator to the main battery. No issues since. There’s a few other threads that also mention a blown fuse that caused dead batteries, I’m guessing it’s the same one.

 

[Bobcat Sig]

It’s seldom one thing. Driving ten miles after drawing down the battery likely isn’t enough to recharge one or both batteries, especially if it’s highway. You want load to drive RPMs which will charge your batteries. I don’t know the output of the Hurricane HO, so more driving is better.

Another likely cause is that one or more cells or cell groups have failed or were malformed during battery assembly. So no manner of driving will fix that.

I had this happen with a few motorcycle batteries where they employed lots of electronics. Voltage looked good, if high at times, while running, but the voltage reading plummeted immediately after stopping the engine. The culprit were bad cells in the OEM batteries. New batteries fix this in both cases.

 

[rpr]

Ram did have a bunch of bad batteries with these trucks but that was not my issue. My truck died while on a road trip and new batteries got me to destination but I had the same issues the following day.

I also didn’t have any parasitic drain while the truck was sitting, the drain was occurring while driving since the blown fuse was preventing the main battery from getting a charge.

But yes, we don’t all have the same issues. It’s very easy to check the voltage on the batteries with the truck running. If you show 13.6V+ on the aux battery and 12.6- on the main battery, your 150A fuse array is likely blown, but that doesn’t necessarily mean you don’t also have parasitic drain or a bad battery.

For me, the root cause was the blown fuse…the $450 out of pocket for 2 new batteries did get me to destination but that didn’t address my issue.

 

[Ryand15]

As the person who began this thread, I purchased a RHO around 3 weeks ago. Loving every minute on it! Thanks guys for all the input.