Addition of Second House Battery

[2xred]

2023 Thor Tiburon 24FB MB Sprinter 3500 chassis

The unit was deliver with 1 house battery and I would like to add a second for more capacity. Any advice on installation or issues with the same?

[Chateau_Nomad]

Caveat:
IF lead acid (flooded, sealed or AGM)...
AND no factory solar on the roof...

If your existing battery is original from the dealer lot, have it load tested BEFORE "dropping in" a companion battery. Dealers have a habit of draining batteries dead... which means they're DOA if not replaced at sale of the rig. IF there's solar, the battery SHOULD be okay. I'd test anyway.

Simplest plan...
If you need to replace the battery, get two identical 12volt batteries. Wire them in parallel. Done. Nothing else to change. You can add as many 12volt batteries in parallel as you have room for and budget and weight allows.

If you have LiFePO4, OR want to switch, that's a different animal beyond this discussion.

[The Gritz Carlton]

I've seen a few of them with 2 batteries. You should have room to just drop another in. Run (+) to (+) and (-) to (-) with two more cables as long as its a 12v battery. You can buy the cables at any battery store or marine retailer. As advised, start this project with 2, new matched batteries. Donate your current battery to the first smoking Camaro you see.

[Scubawise]

Originally Posted by The Gritz Carlton

I've seen a few of them with 2 batteries. You should have room to just drop another in. Run (+) to (+) and (-) to (-) with two more cables as long as its a 12v battery. You can buy the cables at any battery store or marine retailer. As advised, start this project with 2, new matched batteries. Donate your current battery to the first smoking Camaro you see.

We sold both our LFA 🔋 batteries for a good price

[ducksface]

I've read your prior posts.
Due to the skill level you have;
Go to a place that specializes in such.
The nuances involved require tools and ability.

The potentials for disaster are great.

[dkoldman]

Originally Posted by ducksface

I've read your prior posts.
Due to the skill level you have;
Go to a place that specializes in such.
The nuances involved require tools and ability.

The potentials for disaster are great.

[ducksface]

I meant it as a stark warning.
Batteries are much harder to figure out than a curtain surrounding a bed.

I haven't tackled my battery upgrade yet and you've all seen my shop and tools.
They sit, I plan,
I buy the shunt
I plan/read
I buy the colored cables
I plan/read/modify
I buy the BIM
I plan/read/modify/do a fitment
I move the chassis battery
I Plan/read/modify/do a fitment/make a cut
I build a cubby that holds 1500lbs, and add heat pads
I plan/read/modify/do a fitment/make a cut/do the job.

But most importantly;
I read what the op typed, what he didn't type, fill it in, shake it out
And
Make a
Determination
Not
A blanket statement.

I always have.

[2xred]

Originally Posted by ducksface

I meant it as a stark warning.
Batteries are much harder to figure out than a curtain surrounding a bed.

I haven't tackled my battery upgrade yet and you've all seen my shop and tools.
They sit, I plan,
I buy the shunt
I plan/read
I buy the colored cables
I plan/read/modify
I buy the BIM
I plan/read/modify/do a fitment
I move the chassis battery
I Plan/read/modify/do a fitment/make a cut
I build a cubby that holds 1500lbs, and add heat pads
I plan/read/modify/do a fitment/make a cut/do the job.

But most importantly;
I read what the op typed, what he didn't type, fill it in, shake it out
And
Make a
Determination
Not
A blanket statement.

I always have.

I am not offended in the least. I know there are much more talented experienced folks out there than me. I like this forum because it is filled with those folks and I can learn from them and save time and money and agony. I actually have a very good electrical shop that works on RV’s 3 miles from my home so I am very fortunate, and I know I would let them do the work. I know these house batteries are charged in at least three different ways and that not all batteries are made a like or use the same technology or charging or discharging profiles. So I posted the thread to get as much knowledge as I could before scheduling the appointment for the work to add any information I learned from the forum when discussing the work. What I have learned so far is that the batteries need to be identical and of the same type that is already installed and not to try and save money by keeping the original instead of installing two identical new ones.

Now just to defend myself a bit I grew up on a farm and my father was a master craftsman mechanist working in the steel industry I joined the Navy and was trained as a Electronic Technician and afterwards used my GI bill to obtain my electrical Engineering degree, while working as a State Trooper. Then working for Cummins Engine Company programming NC equipment to machine engine blocks and heads etc. I switched to line management and retired as the CEO of a medium sized company. I still have and live on the family farm. I am an avid motorcyclist. Of course I do a lot of maintenance both corrective and preventative on the farm equipment and motorcycles and all things related to the property. I am relatively new to RV’s and find them to be built less robust than most equipment I am accustomed to and most of the equipment is sensitive to deal with without causing more damage when trying to repair or modify the same. This is a picture of my man cave.

Many thanks to all that contributed to this thread it is appreciated

[dkoldman]

Originally Posted by 2xred

I am not offended in the least. I know there are much more talented experienced folks out there than me. I like this forum because it is filled with those folks and I can learn from them and save time and money and agony. I actually have a very good electrical shop that works on RV’s 3 miles from my home so I am very fortunate, and I know I would let them do the work. I know these house batteries are charged in at least three different ways and that not all batteries are made a like or use the same technology or charging or discharging profiles. So I posted the thread to get as much knowledge as I could before scheduling the appointment for the work to add any information I learned from the forum when discussing the work. What I have learned so far is that the batteries need to be identical and of the same type that is already installed and not to try and save money by keeping the original instead of installing two identical new ones.

Now just to defend myself a bit I grew up on a farm and my father was a master craftsman mechanist working in the steel industry I joined the Navy and was trained as a Electronic Technician and afterwards used my GI bill to obtain my electrical Engineering degree, while working as a State Trooper. Then working for Cummins Engine Company programming NC equipment to machine engine blocks and heads etc. I switched to line management and retired as the CEO of a medium sized company. I still have and live on the family farm. I am an avid motorcyclist. Of course I do a lot of maintenance both corrective and preventative on the farm equipment and motorcycles and all things related to the property. I am relatively new to RV’s and find them to be built less robust than most equipment I am accustomed to and most of the equipment is sensitive to deal with without causing more damage when trying to repair or modify the same. This is a picture of my man cave.

Many thanks to all that contributed to this thread it is appreciated
Attachment 44128
Attachment 44129

Well played sir

[Scubawise]

Originally Posted by ducksface

I meant it as a stark warning.
Batteries are much harder to figure out than a curtain surrounding a bed.

I haven't tackled my battery upgrade yet and you've all seen my shop and tools.
They sit, I plan,
I buy the shunt
I plan/read
I buy the colored cables
I plan/read/modify
I buy the BIM
I plan/read/modify/do a fitment
I move the chassis battery
I Plan/read/modify/do a fitment/make a cut
I build a cubby that holds 1500lbs, and add heat pads
I plan/read/modify/do a fitment/make a cut/do the job.

But most importantly;
I read what the op typed, what he didn't type, fill it in, shake it out
And
Make a
Determination
Not
A blanket statement.

I always have.

Well you and others helped me who knows hardly anything about motorhomes.
You had me take pictures & tape all wires.
Installed new AGMs worked the 1st time.
Thanks my Thor friend

[JimOIB]

Lots of Navy ETs on the forum with similar career paths...self-included.

Whatever path you take...take a picture of the current installation and mark your cables. Thor has a habit of using red 2/0 for everything in the battery compartment including the ground cable. And, the terminal lugs are red as well. The only thing that clued me in on my ground cable was a few turns of black electrical tape on them. Good luck.

[Scubawise]

Originally Posted by 2xred

I am not offended in the least. I know there are much more talented experienced folks out there than me. I like this forum because it is filled with those folks and I can learn from them and save time and money and agony. I actually have a very good electrical shop that works on RV’s 3 miles from my home so I am very fortunate, and I know I would let them do the work. I know these house batteries are charged in at least three different ways and that not all batteries are made a like or use the same technology or charging or discharging profiles. So I posted the thread to get as much knowledge as I could before scheduling the appointment for the work to add any information I learned from the forum when discussing the work. What I have learned so far is that the batteries need to be identical and of the same type that is already installed and not to try and save money by keeping the original instead of installing two identical new ones.

Now just to defend myself a bit I grew up on a farm and my father was a master craftsman mechanist working in the steel industry I joined the Navy and was trained as a Electronic Technician and afterwards used my GI bill to obtain my electrical Engineering degree, while working as a State Trooper. Then working for Cummins Engine Company programming NC equipment to machine engine blocks and heads etc. I switched to line management and retired as the CEO of a medium sized company. I still have and live on the family farm. I am an avid motorcyclist. Of course I do a lot of maintenance both corrective and preventative on the farm equipment and motorcycles and all things related to the property. I am relatively new to RV’s and find them to be built less robust than most equipment I am accustomed to and most of the equipment is sensitive to deal with without causing more damage when trying to repair or modify the same. This is a picture of my man cave.

Many thanks to all that contributed to this thread it is appreciated
Attachment 44128
Attachment 44129

Welcome to the forum.
Impressive setup.
I rode all kinds of BMW Motorcycles.
Thanks for your service.
Enjoy life

[Chateau_Nomad]

When you take the DIY path (which I find fulfilling), you are forced to learn how a system works (which I also find fulfilling).

When that DIY system breaks, you already understand how it works, so troubleshooting is MUCH easier.

Those who choose the third party route on things they are easily capable of doing themselves are at the mercy of the third party.

The phrase "I told you so" comes to mind.

[Scubawise]

Originally Posted by Chateau_Nomad

When you take the DIY path (which I find fulfilling), you are forced to learn how a system works (which I also find fulfilling).

When that DIY system breaks, you already understand how it works, so troubleshooting is MUCH easier.

Those who choose the third party route on things they are easily capable of doing themselves are at the mercy of the third party.

The phrase "I told you so" comes to mind.

Well I will never attempt lithium after watching this:

https://www.youtube.com/watch?v=OdKPa3sr79M

[The Gritz Carlton]

Just in case...the "+" is positive and the "-" is negative.

[macdaddy1111]

Lithium batteries and solar rock! Power from god!

Installing 400 watt solar and 400 amp batteries thus weekend if inverter shows up today!

[Scubawise]

Originally Posted by The Gritz Carlton

Just in case...the "+" is positive and the "-" is negative.

Are you serious!

Just joking

[Scubawise]

Originally Posted by macdaddy1111

Lithium batteries and solar rock! Power from god!

Installing 400 watt solar and 400 amp batteries thus weekend if inverter shows up today!

Geez I wish I was not poor

[dkoldman]

Originally Posted by The Gritz Carlton

Just in case...the "+" is positive and the "-" is negative.

Originally Posted by Scubawise

Are you serious!

Just joking

No joke, I still have to pause a bit when the Doctor says my result came out negative. I believe one day when I am old enough I may die from a heart attack induced by own induced fears of a false negative, when it reality it was a true positive. If I test positive + that ain't good, so I guess the goal is to shoot for negative results.

[2xred]

Originally Posted by dkoldman

No joke, I still have to pause a bit when the Doctor says my result came out negative. I believe one day when I am old enough I may die from a heart attack induced by own induced fears of a false negative, when it reality it was a true positive. If I test positive + that ain't good, so I guess the goal is to shoot for negative results.

There really is such a thing as a positive ground.