It is time...for new house batteries! Likely LiFePO4 - calling all DIYers

[Rich W.]

For reference only, @Richpatty's thread:

Move to Lithium

Probably 2/0 then…. :) You can never go to heavy…

rvforums.com

Thats a great thread on a really nice upgrade. I keep a link to it for reference.

 

[Neal]

I'm in a dilemma in how to properly size the battery capacity for LifePO4. My current house batteries (lead acid) are 900 ah (8 x 6V FLA's) and I think we all in general don't go below I'm guessing 70% SOC or anywhere near the min of 50%. So let's call it 300 ah is what we typically have available?

I can certainly go big and all in and put 3 x GC3's in which is 3 x 270 ah capacity. Even just one of these GC3's gives me about the usability capacity I've had for nearly 7 years. Or am I thinking about this wrong?

With that said, is 3 x GC3's overkill? I don't plan to run AC's or anything like that, it's simply boondocking with solar recharging during the day, or gen if no PV (sun) is available. Would 2 x GC3's be the more correct start with what I believe is a very easy expansion later of adding another if desired? I don't want to just throw away $2500 for a GC3 (on sale?) for something I will never really need or use?

My initial plan is leaning towards 2 x GC3's.

So how do you size your battery needs? What is a realistic expectation of LifePO4 capacity for a motorhome?

 

[Richpatty]

Hmmm…. I do think, based on your passed usage and comments, that two units should suffice for 80% of scenarios. It would give you about 100ah more than you have now (based on 50% LA discharged). A third one would just give you more time when the sun does not shine or during late fall/ winter months when the sun does not shine as high or long. Also, you are only one person…and probably not running hair dryers, etc. Also, if you ran down, they charge really quick with the genny as you can run the Magnum charger full tilt and they will take every amp thrown at them. Not like LA which take power at a slower rate….

I figure you could buy two, leave room for a third and decide if you need one more after 6 to 12 months of trying it out…

I will keep thinking about it….
Rich

 

[Neal]

The computer stuff I use is heavy on the power and when boondocking I typically keep the home theater stuff off. High consumers.

 

[Richpatty]

Good point….especially considering the business you are in. That could tip you into a third unit. I guess it also depends on how much you will be off grid.

After having my lithiums for a year and a half (time flies), I like having the extra capacity, but don‘t have any better argument for the third box than that…. And I know they are pricey.

 

[Joe Dutchstar]

We had two 320 ish LiFePo in the CanyonStar, used without air conditioning, were fine for Boondocking. We spent several days on a fireroad In November at 7000' never wanted for power.
The new bus has 960 amps. Went larger due to all electric utilities of Bus, no propane. Using the Gen for power to recharge for now.

 

[Kevin D Pem]

Off grid installations generally have you with enough battery capacity for a week worth of demand!!!

That said, a couple of days storage is likely all you really need at best.

In the past when reservations were not a thing, you could just pull into a resort, if you were inclined. Your posts from the past say you don't rely on solar much anyway. Fuel, is a form of battery, if you want to look at it that way.

My response to this really is for those that are serious about Off grid capacity... if you were one of those people!!! You would also need to consider life cycles, and replacement cost, for a big bank, and that might influence your question the most.

For an example, I am off grid, because of my locational preference, two(2) days worth of power is sufficient. I would need to consider inconvenience that a smaller bank might present when a large storm came through. However a fuel powered generator for backup, would reduce both initial investment, as well as replacement costs.

Really it just translates into bragging rights! Plain and simple!!!

 

[Neal]

We had two 320 ish LiFePo in the CanyonStar, used without air conditioning, were fine for Boondocking. We spent several days on a fireroad In November at 7000' never wanted for power.
The new bus has 960 amps. Went larger due to all electric utilities of Bus, no propane. Using the Gen for power to recharge for now.

Good point in that if it’s in for service it buys you more time.

 

[BGMAC]

While looking into the Lithium myself I came across this company. Seems their prices are cheap, but I don't know much about batteries. Redodo Power—Lithium solar batteries and RV batteries!
They do have one battery that will replace all 4 of my lead acid ones.

Redodo 12V 410Ah (400Ah) Lithium LiFePO4 Deep Cycle Battery

The 400 amp hour lithium battery offers 3200W power and Group 8D size. The actual rated capacity can reach 410Ah. Ideal for solar, boats, RVs, and home backup.

www.redodopower.com

 

[Kevin D Pem]

While looking into the Lithium myself I came across this company. Seems their prices are cheap, but I don't know much about batteries. Redodo Power—Lithium solar batteries and RV batteries!
They do have one battery that will replace all 4 of my lead acid ones.

Redodo 12V 410Ah (400Ah) Lithium LiFePO4 Deep Cycle Battery

The 400 amp hour lithium battery offers 3200W power and Group 8D size. The actual rated capacity can reach 410Ah. Ideal for solar, boats, RVs, and home backup.

www.redodopower.com

re-dodo?

 

[Ddmo]

Neal.

Sorry I'm late to the party, I've been out in the wild a week.

I did build my own Lithium battery bank in 2016. At that time, not much available in 12V already built packages, so I bought Calb cells (16 of them) bus bars, BMS (very rudimentary), heating pad, etc... Built a 720ah pack. I removed old 6 volt AGM's (6 of them) and installed in same bay. The bay was open to fresh air. I did not modify the bay or insulate. I installed remote monitoring temperature alarms (both high and low). Never went off and I never had an issue with temperature, got close a few times, but never an issue. I took the coach to Newfoundland, Alaska, Southwest desert, etc. Never an issue. So I think enclosing the bay completely might not be required in my experience.

All that being said, if I were to do it again today, I'd buy an already built lithium battery pack no lower than 700ah. The 720ah battery I had in my 2014 would last me 2+ days, depending on clouds (I had 960 watts of solar). I had propane stove, so the only drain was the microwave when cooking. Did not set it up for A/C. I know you have all electric, so cooking stove will have a bigger impact on you during boondocking. Only reason I would opt to build again would be for cost savings. Building is not hard and never had warranty issues or any reason to need support, so to me it would come down to cost.

I plan on transitioning my current coach to Lithium after 1 year warranty is up. Very interested in the server rack versions (like the 400ah 12v EG4 LL from Signature Solar).

If you decide to build, more than happy to advise/help out.

DDMO

 

[Rich W.]

re-dodo?

Sometimes the subtleties of a loose translation are lost on certain nonoccidentals.

 

[Neal]

I plan on transitioning my current coach to Lithium after 1 year warranty is up. Very interested in the server rack versions (like the 400ah 12v EG4 LL from Signature Solar).

Interesting options...

Shop All - Batteries - EG4-LL - Signature Solar

signaturesolar.com

 

[Neal]

In chatting with Steve U. that's running Newmar Hoots which I'm at presently he mentioned taking a look at this company:

SOK Battery

SK12V100,SK12V206,SK12V206H,SK24V100,SK48V100

www.us.sokbattery.com

One of the concerns and something to look into is the BMS, internal vs. external and how it plays with Magnum, etc.

 

[Kevin D Pem]

In chatting with Steve U. that's running Newmar Hoots which I'm at presently he mentioned taking a look at this company:

SOK Battery

SK12V100,SK12V206,SK12V206H,SK24V100,SK48V100

www.us.sokbattery.com

One of the concerns and something to look into is the BMS, internal vs. external and how it plays with Magnum, etc.

I agree, I have had to jump start some lithium batteries to get the charge controller to start the charge cycle.