[sportcoupe]

I should have clarified the lithium type upfront. I am looking at LFP (lifepo4) cells. I have experience building HV packs for golf carts using leaf modules. They are not conducive to 12v usage because of their 2p2s module.

Also, the "expected" $0.85/ AH is for a single cell, not the desired whole pack. With just quick searches, I found 400AH LFP cells between $1/ AH and $1.30/ AH. I don't know shipping for just four cells, it could be high.

I won't use FLA, although cheap they are. I don't want to build a sealed enclosure for the gassing smell and they take up a lot of space.

I considered AGM. No gassing problem and they can be side mounted but space is still needed. If you compare usable AH from AGM to LFP, the LFP wins easily.

Drop-in 12v lithium batteries (battleborn, etc,...) are still very expensive. I bet I can build a LFP pack much cheaper.

Use will be a house battery for a campervan conversion. Sort of RV I guess. Think of a DIY Class B RV. I want power abailable and a 12v 400AH pack would do nicely. 600AH would be even better but it's even more money and cells.

 

[sportcoupe]

I'd need eight CALB 180's and it would be short of 400AH.

The cells I'm looking at are LFP 400AH made by GBSystem. About $1/ AH plus shipping.

I am in Savannah, GA

 

[sportcoupe]

It’s only Class B of built by a RV manufacture and titled Class B. Self conversions are still just vans. 😁

Yes 400AH is large, I can afford it and the power will be used. Heck, one day I may add another 400AH in parallel for super power.

CALB 400AH look to be around $500 each. The GBSystem 400AH are $400 each. Much better deal for same capacity and similar specs. Anyone seen 400AH cells for a better price?

 

[sportcoupe]

In a larger motorhome the battery can go under the floor, but in a van it will likely end up on top of the floor, under the bed. Please enclose and vent it appropriately.

I am converting a small van, under 21 feet length. I still will probably install house battery under the floor. Really depends on the house battery I end up getting.

 

[sportcoupe]

Great if you can do it, but good luck with that. The traditional rear-wheel-drive vans fill much of the underfloor space with propeller shaft, fuel tank, and exhaust system... and the remaining space is broken up by the frame and body structure. In what's left, you would ideally want to mount the fresh water tank, grey waste tank, possibly black waste tank, maybe generator, perhaps furnace and/or water heater... and the battery. The Ram ProMaster (Fiat Ducato) is front-wheel-drive and puts the fuel tank under the front seats, so it's a bit better for usable space underneath. What van are you planning to use?

It's easier to build fluid tanks (fresh and waste water) to conform to the available spaces under the floor than to package large rigid blocks of cells to fit.

You are making a lot of assumptions in my van build. Let's stick to creating a 400AH lifepo4 house battery for this forum.

I'm still looking for the best deal source, most likely direct from China. I can wait months for the house battery as I know it's long lead time due to surface shipping, slow boat from China saying is real this time. I'm still scanning Alibaba and Aliexpress for a distributor that would deal in low quantity orders.

 

[sportcoupe]

Correct, four 400Ah cells in series. Simple. If I used eight 200AH cells (4S2P), it's not redundant, it's just more wiring and additional BMS. If 400AH cells are available, that's what I'll use unless there is a spectacular deal on 200AH cells.

To be redundant, I'd have to add a second house battery that came on line when the first one was drained. I don't know why you'd do that.

 

[sportcoupe]

You do not need a BMS for a 4S system. Would be complete waste of money as is using lithium in your application.

I can see the logic in not using a BMS in a 4S system but it would be easy and ensure pack stays balanced. A BMS that small is cheap.

I respectfully disagree that lithium is a waste of money for a RV house battery. To get the same 400AH capacity, you would need almost 800Ah in FLA and deal with the off gassing, maintenance and smell. I won't even get into the space required for a 800AH FLA 12v system.

 

[sportcoupe]

I contacted a distributor for CALB. They informed me the CALB 400AH cells were discontinued.

GBS 400AH cells are only available direct from China, USA distributors don't stock them.

Any other options for 400AH cells? I don't want to parallel cells to keep it simple.

 

[sportcoupe]

Correct, I do NOT know reliable source from China. I see cheap prices but when you request quote they either can't support you or DOUBLE the price to cover "fees".

Do Winston cells have a reliable source? I suspect they are more expensive...

1000AH? I'd love 4 of those bad boys. $$$$$

 

[sportcoupe]

I have yet to find the rumored $0.85/ Ah except for the very questionable direct from China sites (Alibaba, Ali Express, etc...).

I have found 400AH cells for $1.24/ Ah plus shipping and will probably go with that if prices don't come down.

For the gotta have the biggest folks, Winston has 700Ah cells for the same $1.24/Ah and mighty HUGE 1000Ah cells for even cheaper, $1.19/Ah. Both plus shipping.

 

[sportcoupe]

The BMS will never turn on, last thing you want to do is fully charge a Lithium battery which is required for a BMS to even turn itself on. Just float them at 13.8 volts. and set your Inverter to trip off-line at 11.5 volts. .

That's exactly what I was thinking for a non-BMS 4S pack. Seems to work well for others.

I respectfully disagree that lithium is a waste of money for a RV house battery. To get the same 400AH capacity, you would need almost 800Ah in FLA and deal with the off gassing, maintenance and smell.

I have no clue where you came up with that?

You disagree that FLA's have off-gassing, maintenance and smells?
You can't argue that discharging past 50% will shorten the life of a FLA.

A good higher end FLA like a Trojan Industrial or a Rolls 4000 or 5000 series has the exact same usable capacity of 80% capacity. However will live a lot longer than any Lithium battery.

I just saw the Rolls have a 7 year warranty, that is very impressive. I haven't heard of them till now. I have experience in traditional Trojan 12v FLA and they only provide ~3 years service in golf carts.

While FLA are proven technology, I'd much rather prefer a sealed battery in my camper. I see Trojan has high capacity 250Ah 12v AGM's but they only have a 1 year warranty. Any thoughts on a quality AGM with at least 250Ah size and a great warranty? I could parallel two for a 500Ah pack in the future.

 

[sportcoupe]

.....

Dereck,


Thank you for valuable feedback. I read your posts at LEAST three times so they sink in (that almost sounds like Sunking, LoL).


You have me completely rethinking my plans based on the facts you provide.

 

[sportcoupe]

Just a reminder of the OP topic

Correction. Topic is:

400AH lithium cells? Best price per AH? $0.85/ AH?

Only a few posts addressed the topic.

 

[sportcoupe]

Because the distribution channels for good quality LFP are very limited, no way to get much below the 5-7x premium over lead.

Lower pricing without compromising quality is IMO a matter of luck with a once-off deal, very rare.

And taking chances with unknown makers or dodgy middlemen, again you may get lucky, but you may not really find out for many years.

I have seen the light, there isn't cheap high capacity lifepo4 cells available yet.

I have been looking at industrial 6V AGM's now for my camper van build.

 

[sportcoupe]

But you have people who insist on electric cooking, refrigeration, and the impossible air conditioning requires a lot of power that a 12 volts is just not capable of doing safely, efficiently, and economically.

I agree 12 volts makes the most sense sense for most applications. But when you throw electric cooking, electric refrigeration, and air conditioning into the mix..........

Air conditioning is not impossible on batteries. You are limited in how long you can run it. A simple van doesn't need 16k BTU a/c unit, a 5k BTU cools a small van easily. That's 420 watts for a basic 5k BTU unit. It's a lot, but not impossible.

My 12v fridge runs on 40 watts and it only runs 20 mins an hour tops.

I still have to source an efficient microwave that will still pop popcorn.

 

[sportcoupe]

in the US market, stick to Lifeline, Odyssey and Lifeline.

Maybe Firefly if PSOC abuse is unavoidable.

I've heard Trojan's getting out of AGM (again), Deka's are meh not really deep cycling, Rolls are outsourced.

But we do you think AGM is required?

Much higher cost per AH per year, much easier to murder, need more precise and higher-current charge sources for lingevity.

You said Lifeline twice. What about Full River?

I don't want to deal with messy FLA. I have 140 amps available to charge AGM.

 

[sportcoupe]

I’ve already stated “why” for AGM.

 

[sportcoupe]

There seems to be three choices for batteries. FLA, AGM, and flavors of lithium.

Automakers are already switching to AGM. Lithium isn’t readily available in high capacity cells.

 

[sportcoupe]

What do you want to know?