Aux Battery Swap for H8 Main Battery

[frogjbm]

Hey I just saw a post on the FB forum regarding an Aux battery and swapping it over for an H8 main battery?

First - is the guy that posted that on FB on this forum? Dusty Waterfall?
Second - very interested to understand what you intend to do and your reasoning. I'm assuming because clearly the batteries coming from the factory suck balls.

Thank you

 

[gram10]

Curious myself

 

[Irongoats]

I'm assuming because clearly the batteries coming from the factory suck balls.

^^This!

 

[MurphNH]

Wonder how he did the delete? In my wrangler you just take out a fuse and can then you can disconnect the battery. As a bonus taking out the fuse kills start stop so one less button to push every time.

 

[405Forged]

You can swap them out. Done it on the last three trucks I’ve owned. It’s the same battery location as the hemi and with the etorque. I probably have around 120k miles between three trucks in the last 4 years and they all get swapped. I plan on doing it to this truck when I get it home next week.

Modifications:
You will lose the little wedge piece that is on the side of the battery because the H8 battery is about 2inches longer maybe at lost(never measured). But it still gets secured in the tray just fine with the hold down bolt and clip on the front of the battery.

FYI: people that still want a battery cover, Ram makes them and you can order them from the dealership or eBay either one.

As far as batteries go, there is I think 3 major battery manufactures in the world. So go for the one with the best warranty. Last I checked the Walmart Platinum AGM H8 900CCA batteries still had the 3 year replacement promise. Cost for the battery with core will be about 200 bucks depending on which Walmart you live near. Make sure you look for the battery with the newest (freshest) manufacture date on it.

 

[frogjbm]

You can swap them out. Done it on the last three trucks I’ve owned. It’s the same battery location as the hemi and with the etorque. I probably have around 120k miles between three trucks in the last 4 years and they all get swapped. I plan on doing it to this truck when I get it home next week.

Modifications:
You will lose the little wedge piece that is on the side of the battery because the H8 battery is about 2inches longer maybe at lost(never measured). But it still gets secured in the tray just fine with the hold down bolt and clip on the front of the battery.

FYI: people that still want a battery cover, Ram makes them and you can order them from the dealership or eBay either one.

As far as batteries go, there is I think 3 major battery manufactures in the world. So go for the one with the best warranty. Last I checked the Walmart Platinum AGM H8 900CCA batteries still had the 3 year replacement promise. Cost for the battery with core will be about 200 bucks depending on which Walmart you live near. Make sure you look for the battery with the newest (freshest) manufacture date on it.

Super helpful thanks for the write up!

 

[moparfiend]

Since my truck is being a POS with electrical at the moment, I'd like some additional details on this and don't know anything about battery's other then we have 2 in the RHO and they are generally considered garbage.

H8 appears to be a battery size
So that will fit in the factory location for the tiny aux battery, but the cover or tray will need cut/modified ?

You mentioned a battery cover that will fit from mopar, do you have the part number for that?

Does this impact the charging system at all? Or does it just work to keep both battery's at peak?

 

[gram10]

From FB

 

[moparfiend]

Ohhh, i see, it's a larger primary battery that takes it from 2 batteries to 1. Now that's making more sense to me.

 

[TheBarBack]

Someone do this and report back before I have another dead battery!

 

[ah64aviator]

Ohhh, i see, it's a larger primary battery that takes it from 2 batteries to 1. Now that's making more sense to me.

I didn't get that part myself at first blush. You're not alone.

 

[Banger]

For me, the questions are:

What is the advantage of replacing 2 batteries with one H8?
What is the downside to it?

I understand the factory batteries suck. But what's the advantage of the new configuration? Why not just upgrade the two?
Not being a contrarian, just seriously curious as to why.

 

[Eighty]

What size(s) are the factory RHO batteries?
Previous trucks (my TRX included) shipped with an H7 battery. I upgraded mine to an Odyssey H8. Despite what people said, it fit perfectly in the tray and the blanket didn’t need to be replaced. It was a straight swap with no parts/mods required.

 

[gram10]

Aux battery size: https://www.autozone.com/batteries-...y-bci-group-size-400-200-cca-aux14/755654_0_0
Main battery size:

Duralast Platinum AGM Battery BCI Group Size 94R 850 CCA H7-AGM

Shop for Duralast Platinum AGM Battery BCI Group Size 94R 850 CCA H7-AGM with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

From what I read in various places, mostly jeep gladiator related, the auxillary batteries seem to die easily and then drain the main battery fairly quickly, i guess the idea here is a bigger battery to take the place of the two our truck came with and I guess the less complex way seems to come with less battery issues

I may give it a try, I'll see if I have any time in the near future

 

[eltaco]

Such a strange issue with the current trucks as I’ve never encountered a new battery failing so rapidly. With those who have had batteries replaced on their new RHO, are the new batteries working out better?

 

[Banger]

Aux battery size: https://www.autozone.com/batteries-...y-bci-group-size-400-200-cca-aux14/755654_0_0
Main battery size:

Duralast Platinum AGM Battery BCI Group Size 94R 850 CCA H7-AGM

Shop for Duralast Platinum AGM Battery BCI Group Size 94R 850 CCA H7-AGM with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

From what I read in various places, mostly jeep gladiator related, the auxillary batteries seem to die easily and then drain the main battery fairly quickly, i guess the idea here is a bigger battery to take the place of the two our truck came with and I guess the less complex way seems to come with less battery issues

I may give it a try, I'll see if I have any time in the near future

That makes sense. Also makes me wonder why they just don’t put a bigger one in at the factory instead of two smaller ones.

 

[jb37]

prolly cuz one big AGM battery is $$$ vs a smaller AGM and standard battery

 

[Woga]

Aux battery size: https://www.autozone.com/batteries-...y-bci-group-size-400-200-cca-aux14/755654_0_0
Main battery size:

Duralast Platinum AGM Battery BCI Group Size 94R 850 CCA H7-AGM

Shop for Duralast Platinum AGM Battery BCI Group Size 94R 850 CCA H7-AGM with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

From what I read in various places, mostly jeep gladiator related, the auxillary batteries seem to die easily and then drain the main battery fairly quickly, i guess the idea here is a bigger battery to take the place of the two our truck came with and I guess the less complex way seems to come with less battery issues

I may give it a try, I'll see if I have any time in the near future

We were one of the early gladiator victims with a 2020 delivered in 2019. One morning all lights in the cab and dash for flickering and wouldn’t start. Couldn’t jump it - Dealer came and picked it up. Had 2 tries - first the main battery then the aux. 5+ years later and all batteries still going strong. More than happy with outcome

I think as someone said above one battery draining the other compounded with a long ride of no activity pre delivery.

 

[MattH89]

Why would you remove the aux battery in this case? Even if you upgraded the main battery, wouldn't it still be better to also have the aux vs not having it?

 

[MurphNH]

Why would you remove the aux battery in this case? Even if you upgraded the main battery, wouldn't it still be better to also have the aux vs not having it?

When the aux battery dies it drains the main battery in a lot of cases leaving you with two dead batteries. Would be nice if they set it up so it would isolate the battery when it dips below 11 volts but that is not the case. With the RHO it seems to be two fold issue. 1 there are a bunch of guys who just got bad batteries. 2 Something in the system does not turn off or randomly turns on and kills what would be a good set of batteries. Option 2 happened to me last week when the truck decided to turn itself on at 10pm until it killed my batteries a little after 2am. Both batteries were down to 4 volts but took a charge in the morning and I have had zero issues since.