li fe po4 battery upgrade?

Mr Wizard,

KJINTF has a single 12 volt 200 amp-hour battery, so there are not the internal balancing problems of multiple jars.

I plan to do a LOT more research before opening my wallet. I don't need to have anything installed until late November.
Don-thanks for the link it fits well with my line of thinking which provides a level of comfort.

While I was in Quartzsite I stopped in to a couple of solar installers to discuss lithium batteries. One shop has no plans to handle them till the price drops a lot. The other shop carries Relion batteries. While I was talking to them 2 customers came in and bought Li. They were selling the 100 Ah for $1250 and the 300 Ah for $3100. The big one is in a 8D case.

MrWizard wrote:
but as 2oldman can attest in doing his research, that is not what he was told

In going to 48v I was advised it's best to have a single battery pack. With a 12v system a series or parallel arrangement is "not a problem."

Phil

i would like to agree with you, it seems it should be that way

but as 2oldman can attest in doing his research, that is not what he was told

it seems it is not just a matter of recharge
but also a matter of controlling output in a balanced manner
the BMS in hybrid/electric vehicles or a power wall is complicated afair

it would be interesting IF "KJINTF" came back and post a few pictures of his batteries and the BMS involved

I thought I saw 100 ah batteries somewhere near Ontario or the San Gabriel Valley in CA for about $500 each, from China. do a search to find them, save yourself a bunch of money.

N8GS wrote:
I am thinking of using the StarkPower batteries but there are other options. Stark is running a special on the 100 Ah units at $899 each.

Ok, I see those are the cheapest out there. Be careful, when spending this kind of bucks I wouldn't be going for the cheapest I could find.

KJINTF wrote:
Going on two years now added four 200amp/hr LiFeMnPO4 Prismatic cells
They have been wonderful to say the very least
Contrary to popular belief they are not difficult to charge properly
Suggest you look at the Prismatic cells as compared to the "Drop In Replacements" which are made of dozens of smaller cells in a series / parallel configuration
Check out the Boating forums lots of good hands on info available

Tell us more about your prismatic cells. I believe my VW e-Golf has the exact same battery chemistry as what you are mentioning, with prismatic cells. 24.2 kwh of capacity, about 22kwh usable.

I guess I fail to understand why that, intrinsically, multiple Li standalone, drop-in type Lithium based batteries (i.e. batteries with built-in charge management circuitry) can't be ganged together - in a BALANCED configuration - just like lead acid batteries can be and should be.

It seems like the Li battery's built-in charge management circuirty should not care about, or know about, other batteries around it if they are all seeing identical external loads, as they do if hooked up in a balanced way. "Hooking up in a balanced way" is merely a matter of maintaining - among all the batteries - equal current path resistance (i.e. equal cable lengths) to the loads whenever multiple batteries of the same voltage are interconnected in a parallel configuration. This assumes that all of the drop-in type Li batteries in a multiple battery bank are the same age of the same model from the same manufacturer.

KJINTF wrote:
Going on two years now added four 200amp/hr LiFeMnPO4 Prismatic cells
They have been wonderful to say the very least
Contrary to popular belief they are not difficult to charge properly
Suggest you look at the Prismatic cells as compared to the "Drop In Replacements" which are made of dozens of smaller cells in a series / parallel configuration
Check out the Boating forums lots of good hands on info available

Wasn't that you, that had a complete new install designed by your son the solar power design engineer ?

Or was that somebody else ?

Lithium sales people have been touting drop in REPLACEMENT for over 5 years
But does not seem to be a reality, in anything more than a one off REPLACEMENT..

When you get into Banks of batteries, it is harder to use single drop ins and have them work together with out problems appearing

I am the OP
To answer some of the questions and comments.
I like to dry camp, just got back from Quartzsite, AZ. We spent 8 weeks dry camping at Q.
I currently have 600 Ah on board. thats 4 Trojan T1275 batteries.
I can easily reconfigure my Outback charge controller for use with LiFePO4.
The batteries I am looking at do have BMS. I am thinking of using the StarkPower batteries but there are other options. Stark is running a special on the 100 Ah units at $899 each.
I have looked at the PD charger/converter and it is also the recommended by StarkPower.
As some of you know I do a lot of research before committing to a final solution.
Pin weight reduction on my FW is also an issue that I am addressing.