$140 dual 12v battery DIY swap

[Giddy89]

Been cruising around for the last 2 months with a service 12v battery error. Finally got around to doing a DIY swap. Total cost for the 2 batteries as well as 2 pairs of SOONISH battery post relocators was $140

I used these batteries which were $38 each at the time

https://ebay.us/m/emkvVF

2 pairs of the soonish battery post relocators, as well as 4x 1/2 inch aluminum spacers to put on top of the mighty max battery posts to get the relocator tabs some clearance

I followed the ohmmu dual 12v swap video. It was a tight fit and I had to reorient the sensors on the negative 12v leads but it works.

Hard reset cleared all codes for me. Better than the $900ish rivian is asking. You’re welcome

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[jplblue]

Thanks! Did you happen to document with pictures?

 

[sherold]

Interesting, thanks for posting . Looks like a solid potential for aftermarket replacements. I am curious how the quality is on these and, how they hold up.

 

[sherold]

Available on Amazon as well...
MightyMax ML18-12int

 

[mudito]

Neat!

 

[Giddy89]

Thanks! Did you happen to document with pictures?

Sorry, I did not snap any pics. Didn’t really think this needed a whole write up but just wanted the community to know it’s an option that exists should you choose to undertake the swap.

I’m really hoping that we begin to see more DIY fixes for the common issues as these trucks get beyond the bumper to bumper warranty.

 

[sherold]

If you get a chance, even a finished product picture of the battery installed would go a long way for members of this group. Some seem to be too familiar with the digital/electronic realm vs. the mechanical ways of the world

 

[FooF]

Available on Amazon as well...
MightyMax ML18-12int

Reviews are terrible for these batteries

 

[sherold]

Reviews are terrible for these batteries

Reviews are also great for these batteries.

 

[CrazyOne]

Rivian OE batteries are deep cycle batteries. This one doesn't seem like it is. AGM deep cycle batteries will be better, but it's great that you were able to replace them.

 

[mkhuffman]

Rivian OE batteries are deep cycle batteries. This one doesn't seem like it is. AGM deep cycle batteries will be better, but it's great that you were able to replace them.

It looks like you are correct:

Feature	Starting AGM	Deep Cycle AGM	Dual-Purpose AGM
Plate Design	Many thin plates	Fewer thick plates	Medium thickness
Primary Strength	High CCA (quick bursts)	High cycle life & reserve	Balanced starting + cycling
Recommended DoD*	Avoid >20–30% regularly	50–80%+ regularly	30–50% regularly
Typical Uses	Car/truck starting, powersports	Solar, RV house, trolling motors	Marine starting + accessories
Cycle Life (approx.)	Lower (fewer deep cycles)	Higher (hundreds to 1000+)	Moderate

(Source: Grok)

These appear to be Starting AGM batteries.

Personally, I would worry about an early failure since the R1 is probably deep cycling the batteries on a regular basis.

 

[CrazyOne]

It looks like you are correct:

Feature	Starting AGM	Deep Cycle AGM	Dual-Purpose AGM
Plate Design	Many thin plates	Fewer thick plates	Medium thickness
Primary Strength	High CCA (quick bursts)	High cycle life & reserve	Balanced starting + cycling
Recommended DoD*	Avoid >20–30% regularly	50–80%+ regularly	30–50% regularly
Typical Uses	Car/truck starting, powersports	Solar, RV house, trolling motors	Marine starting + accessories
Cycle Life (approx.)	Lower (fewer deep cycles)	Higher (hundreds to 1000+)	Moderate

(Source: Grok)

These appear to be Starting AGM batteries.

Personally, I would worry about an early failure since the R1 is probably deep cycling the batteries on a regular basis.

I saw deep cycle batteries for about $20 more on Amazon from the same brand. Not sure if they are the same size. I also haven't heard of the brand before.

Yeu are correct. Non deep cycle battery will fail quickly.

 

[Tim-in-CA]

I recall that Rivian is committing you allowing consumers to purchase the 12V batteries and service themselves. They will most likely still be stupidly expensive.

 

[dradam]

Thank you for posting this. I keep a charged full throttle battery with soonish battery posts attached in my frunk. I have just one 12V. I 3d dprinted a safety cover and spacing shim for installation and have tools in the frunk and trailor hitch to swap my 12V if it dies. good to know the hard reset clears the codes. I have not had to do a swap yet but glad to see that it worked for you and gives me confidence that my setup will work if it is needed.

https://www.printables.com/model/1387546-rivian-shim-and-cover-for-a-backup-replacemant-12v

 

[NY_Rob]

The brand "MightyMax" is okay quality wise. I've used their 7Ah and 9Ah SLA batts (same type as the OP used and linked) as replacements in small UPS's and some of their larger Ah sizes in UPS's that carry a whole building. No issues with any of them, but in a UPS they seldom get used and almost never ever get deeply discharged.

If these batts last more then 2yrs, then they're a bargain.

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