Future of DIY LiFePO4 looks bleak…

[fafrd]

Cells cost $40ea for 2020 date code unused cells from batteryhookup. Shipping was $6/cell for $736 total. BMS was $150 if I recall. Right now 18650 store has 2023 date code LF105 cells for $45 + ship.

Chances are those OTS batteries are being sold at below cost to move old inventory. It seems that there would be no profit margin at those prices since LFP battery cost from manufacturers is at $100/kWh this year which makes LF105 cost $33.6 / cell to source.

Thanks.

So $196 for 4 cells shipped plus $150 for the BMS, or $346 for a 105Ah 4S battery.

I’m sure the DIY batteries you have built are superior to the 100Ah OTS batteries available on Amazon (especially because of the 250A BMS, which was your primary motivation), but they are also nearly twice as expensive:

$346 / 1344Wh = $0.25744/Wh

$170 / 1280Wh = $0.13281/Wh

You could have spent the same money on 8 OTS batteries to deliver 80% of the peak power rating with 190% the energy capacity…

 

[AntronX]

Cells were $46 shipped * 16 = $736

3.2 * 105 * 16 = 5.376kWh
$736 / 5.376 = $137 / kWh.

I exclude BMS because I don't consider BMS to be consumable item because it can be reused or sold. Can't do that with built in BMS in Amazon batts.

 

[fafrd]

I've got just over $9K into three 304ah batteries with "grade A" cells and a bms that will communicate with my inverter. I don't see how I could do that buying premade batteries. That's over $13K in Signature Solar batteries to do the same. And if I made them today, it would be even less.

Again, special requirements including BMS communication is a different ball-‘o-wax.

But a 304Ah 48V / 16S battery for $3000+ is not particularly cheap ($3000.00 / 15,565Wh = $0.1927/Wh.

The 100Ah 12V OTS batteries on Amazon I referenced are $170 each or $0.1328/Wh.

So 4 x 3 = 12 of them would run you $2040 for 300Ah or Les than 2/3 the cost for nearly the same capacity.

Or you could splash out for 4 x 4 = 16 delivering 131.6% the capacity for $2720, or 90% of the cost…

Again, special requirements such as BMS communication or rackmoumt is a different discussion, but you could easily have delivered 912Ah of 48V LiFePO4 storage for less than $9000 using OTS batteries…

 

[AntronX]

So $196 for 4 cells shipped plus $150 for the BMS, or $346 for a 105Ah 4S battery.

$46 x 4 = $184 for 4 cells shipped. One $150 BMS for all 16 cells. Not one BMS per 4 cells.

 

[fafrd]

Cells were $46 shipped * 16 = $736

3.2 * 105 * 16 = 5.376kWh
$736 / 5.376 = $137 / kWh.

My mistake - I thought those were 4S / 12V batteries from the pictures, not 4S / 12V batteries…

So $736 for the 16 cells + $150 for the BMS would be $886 / 5376Wh = $0.1648 / Wh (124% of the recent Amazon OTS reference).

I exclude BMS because I don't consider BMS to be consumable item because it can be reused or sold. Can't do that with built in BMS in Amazon batts.

If you are really motivated to reuse an old BMS, you can salvage one out of a spent OTS battery but that would almost certainly mean building a DIY battery to reuse it .

 

[fafrd]

$46 x 4 = $184 for 4 cells shipped. One $150 BMS for all 16 cells. Not one BMS per 4 cells.

Yeah, understood my mistake from your previous post.

$0.1648/Wh, not $0.25744/Wh.

 

[AntronX]

If you are really motivated to reuse an old BMS, you can salvage one out of a spent OTS battery but that would almost certainly mean building a DIY battery to reuse it .

Yep and it's not even in the same class of BMS. This one has blutooth monitoring, adjustable cell limits, fuel gauge, lower Rds of MOSFETs, higher amperage and not needing to crack open glued together plastic battery cases.

 

[justgary]

I'll add that my 200 amp JBD BMSs came with 4 gauge copper plated wire. I swapped it out for 2/0 copper welding wire. Who knows what you might get in a factory unit?

 

[fafrd]

Yep and it's not even in the same class of BMS. This one has blutooth monitoring, adjustable cell limits, fuel gauge, lower Rds of MOSFETs, higher amperage and not needing to crack open glued together plastic battery cases.

As I said, specific requirements is a whole different discussion.

The thread is about commodity-level pricing of OTS versus DIY LiFePO4 batteries (or rather, the ever-diminishing gap between the two).

 

[ArthurEld]

DIY brings pre built to market faster. That is part of the purpose of DIY.
If I needed more batteries I would consider pre built.
Now that I know how to put batteries together I will probably always feel I can do a better job myself.
The weather proof enclosures with heating and cooling are hard to DIY. I look forward to the price coming down on that tech. Hopefully DIYers will make that happen.

 

[Danke]

I've got just over $9K into three 304ah batteries with "grade A" cells and a bms that will communicate with my inverter. I don't see how I could do that buying premade batteries. That's over $13K in Signature Solar batteries to do the same. And if I made them today, it would be even less.

I can buy 6 280Ah rack batteries for $9K, delivered.

 

[AntronX]

I can buy 6 280Ah rack batteries for $9K, delivered.

48V ? That suggests $105/kWh. Amazing price if true.

 

[Danke]

48V ? That suggests $105/kWh. Amazing price if true.

Yes, 16S

 

[AntronX]

Yes, 16S

Wow, got link?

 

[Tulex]

I can buy 6 280Ah rack batteries for $9K, delivered.

Where?

 

[Danke]

Where?

From China.

shirleyHu@xuhotrong.com
whap number: +86 15622195049

For a little more you can buy them with EV grade cells.

 

[Tulex]

From China.

shirleyHu@xuhotrong.com
whap number: +86 15622195049

For a little more you can buy them with EV grade cells.

All fine and dandy, but what are the batteries? There are batteries all over the place that don't come close to performing to the battery specs.
What are the cells, the bms, cycles, etc. What's a little more? Got a picture of this battery? Right now, it's just a phone number.

 

[Danke]

All fine and dandy, but what are the batteries? There are batteries all over the place that don't come close to performing to the battery specs.
What are the cells, the bms, cycles, etc. What's a little more? Got a picture of this battery? Right now, it's just a phone number.

DYODD

 

[JJJJ]

DIY, like a mechanic is a skill set. There is no question that a prebuilt is quicker and more convenient. Cost differences have changed in the past year.

Computers were also more DIY when they came out. Now I can buy an integrated unit which does a lot more than the old days for a little over $100.

With integrated technology repairs to current computers are a little more "interesting" than the old days.

There are a lot of server rack batteries being sold. I suspect, like automobiles that a repair market will emerge in the future for this technology. Buyers will be hesitant to just throw away these cases when a BMS or other component fails. They could be motivated to find someone with the skills to make the needed repairs to salvage their investment.

That is when DIY shines. These are the potential future "mechanics" for the solar industry. My mechanic makes top dollar for repairing cars. I suspect those who keep their DIY skills fresh could potential branch out in new and interesting occupational pathways in the future.

 

[TimE]

So many people seem to focus on the price. I can get a "blah, blah for this little money". If you focus on the specification rather than the cash, you would find you are not comparing like for like. None of the prebuilt cheap batteries from China can certify cell origin or grade of cell. Often, there is no Bluetooth or active balancer. These reasons alone are why I build my batteries. I buy the cells from a reputable US supplier, and I buy the best 200A
FET based BMS currently available on the market. The quality of my DIY battery is far higher than a cheap drop in. For the same specification, my batteries cost less.
I don't want dumb lithium on my boat where I can't see cell voltages. If you develop a bad cell over time you will get a battery shut down. You will have no idea what is causing it and you won't have a way of fixing it without cutting the battery open. If the cells have been spot welded together, and you have a bad cell, the battery is scrap. Not so with DIY