Question Replacing house batteries

[lostinfla]

Looking forward, I am considering replacements for the house batteries. Current setup is 8 flooded 6v. We don't really ever dry camp and usually only use the inverter when driving to keep everything running. Not sure if Lithium is in my future although it is an option. I was thinking of going with only 4 AGM batteries to save weight. (I understand lithium would be much less weight, but cost is an issue over AGM) I'm thinking they should run the fridge and other components for the 6 or so hours on the road. Has anyone cut back on the house bank, and if so, any issues?

 

[Richpatty]

It might be an option to go Lithium, but with less of them as well. I bet you could get away with only 200-300 amp hours and be fine. You would save a lot of weight.

Will be curious what others think.

 

[Sealyn]

Your alternator will charge as you
drive, but I would replace all 6 with AGMs.

 

[Neal]

I would only buy LiFePO4 going forward. Here is your homework assignment.

What is your amp hour requirement?

What is your cost per usable amp hour?

How long will the battery last and how long is the warranty?

Available aH - AGM you get 50%. LiFePO4 90%.

 

[lostinfla]

Yes, I'm aware the LiFePO4 has more useable energy compared to flooded or AGM, but the fact that:
1. I really don't want/need to go with solar
2. At this point, not sure just how long I'll be keeping the coach, so cost vs return is an issue.
3. I know going either Lithium or cutting the bank in half will save a lot of weight.
4. I really don't know the actual amp hour requirements for our type of camping. The standard battery setup will run our load on the inverter for over a day, but as stated, the only time I really need inverter power is while driving down the road, so I'd like to loose a little weight (the coach, that is)

Any tips on Lithium or AGM units, as far as dependability and price are appreciated. Thanks!

 

[lostinfla]

This seems to get good reviews.

 

[BGMAC]

When I replaced mine last year I went with LiFePO4. I went from 4 lead acid 100 ah each to 1 400ah. The cost was about the same or even less depending on the battery you by. I think mine was about $800. We don’t boon dock much either, but in my mind give a better resale value of the motorhome.

 

[Neal]

People need to stop associating LiFePO4 with solar, there is NO connection. My airplane has LiFePO4 because it's a better battery, lasts at least twice as long, therefore more cost effective, charges much faster, on and on.

As the battery will likely last 10+ years, that needs to be weighed into the cost (you'll likely replace your AGM's twice in the lifetime of the Lithium), however, yeah, you may not keep the coach that long. I'd say it may help in resale but there is no money to be made in resale of coaches, it's a gonner.

There is more labor involved in the first switch to LiFePO4 as you have to seal the battery bay and you have to be temperature aware.

You not only save weight but once your battery bay is "renovated" you now gain a ton of storage too.

 

[BGMAC]

People need to stop associating LiFePO4 with solar, there is NO connection. My airplane has LiFePO4 because it's a better battery, lasts at least twice as long, therefore more cost effective, charges much faster, on and on.

As the battery will likely last 10+ years, that needs to be weighed into the cost (you'll likely replace your AGM's twice in the lifetime of the Lithium), however, yeah, you may not keep the coach that long. I'd say it may help in resale but there is no money to be made in resale of coaches, it's a gonner.

There is more labor involved in the first switch to LiFePO4 as you have to seal the battery bay and you have to be temperature aware.

You not only save weight but once your battery bay is "renovated" you now gain a ton of storage too.

True, I do not have solar. My reason to change was longer life, less maintenance.

 

[Neal]

AGM's can boil off and have a short life, they can die due to discharge too low, LiFePO4 have a BMS that prevents that. They are more fool proof as well.

 

[newmarokie]

Neal,
What kind of aircraft do you have? With all the "yellow tag" stuff and approvals, was the LiFePo battery replacement a logbook concern?

 

[Neal]

Neal,
What kind of aircraft do you have? With all the "yellow tag" stuff and approvals, was the LiFePo battery replacement a logbook concern?

Experimental so I can do anything I want. Carbon Cub FX-3. But the EarthX batteries are certified as well.

 

[newmarokie]

gotcha

 

[lostinfla]

People need to stop associating LiFePO4 with solar, there is NO connection. My airplane has LiFePO4 because it's a better battery, lasts at least twice as long, therefore more cost effective, charges much faster, on and on.


There is more labor involved in the first switch to LiFePO4 as you have to seal the battery bay and you have to be temperature aware.

You not only save weight but once your battery bay is "renovated" you now gain a ton of storage too.

I am aware there is no connection with solar, but most that I have seen go Lithium with solar panels for off grid camping. I just want to loose some weight on the drivers side of the coach and have power without having to worry about going below 60% SOC. I think I'm sold on LiFePO4, but just what is involved with sealing the battery bay? How have those who have lithium done this? I'm sure I could figure it out, but best to learn from those who have.

 

[Richpatty]

Here was my conversion….

Move to Lithium

So as I get ready for my Lithium project, I began to think about the best way to wire them. I will have 8 100ah GC2 sized battleborns. I know many of you use the wiring method on the left (see below). I have seen articles that say the diagram on the right pulls power from the batteries...

rvforums.com

Go to the last page for the steps on enclosing it.
Hope it helps
Rich

 

[lostinfla]

Thx Rich, I'll check it out

 

[BGMAC]

I am aware there is no connection with solar, but most that I have seen go Lithium with solar panels for off grid camping. I just want to loose some weight on the drivers side of the coach and have power without having to worry about going below 60% SOC. I think I'm sold on LiFePO4, but just what is involved with sealing the battery bay? How have those who have lithium done this? I'm sure I could figure it out, but best to learn from those who have.

I’m not sure if you really half to seal it unless you’re going to use the Rv in extreme temps or the battery compartment is vulnerable to debris. I did do mine with thin metal sheets I could bend by hand and self tapping sheet metal screws.

 

[Neal]

Good point, I'm not sure where the "seal the bay" comes from, I don't think it's required other than for temps. But you can take the opportunity to make it a great bay for storage, etc. as I gained a lot of storage space in mine. You could get creative and build a battery box, etc. I believe and that would work which is what ended up happening with mine simply to enclose them as they don't need to be vented like AGM/FLA require.

 

[MarkMaxPayne]

Good point, I'm not sure where the "seal the bay" comes from, I don't think it's required other than for temps. But you can take the opportunity to make it a great bay for storage, etc. as I gained a lot of storage space in mine. You could get creative and build a battery box, etc. I believe and that would work which is what ended up happening with mine simply to enclose them as they don't need to be vented like AGM/FLA require.

Agree. In my prior rig I installed BattleBorn as drop in replacements and didn't seal where they were located. I didn't intend on using the rig in extreme weather and the internal bms built into each of the batteries would have protected them anyways if I had tried. If they come with an internal bms and/or heater built in (or you install a battery heating pad) I also don't see a "requirement" or need to seal the bay. Even an external bms should have a temp sensor to protect trying to charge them in extreme cold.

-Mark

 

[redbaron]

This is a really tempting battery. 2 of these would replace the 8 I have now due under 2k

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