Who is still building DIY batteries

[MattiFin]

Which is why I'm seriously considering building a 1 MWh battery pack at the moment. The way cell prices are evolving, this shouldn't even be super expensive. I could use 10 kWh a day and bridge my winter even with zero solar coming in.

If prices drop to 50usd/kwh that is still 50k usd pack. You get 20 seasonal cycles out of it?

2500 usd per cycle or 2,5usd/kWh… I’d still keep burning something, anything

You would need couple of neighbours to share the smallest Volter CHP power plant..

 

[OffGridForGood]

Just need to modify the gasifyer - to allow wood gas to run your generator in the winter months, while it heats your place!

 

[upnorthandpersonal]

Thinking that would be cost prohibitive?

If prices drop to 50usd/kwh that is still 50k usd pack. You get 20 seasonal cycles out of it?

Currently, I would be looking at cell cost of around 70k directly from EVE. However, I can get this lower. I'm involved with several projects that will need a ton of cells (multiple MWh packs). If these all go as planned, I'll be able to ship my cells as part of a very large order and will have them well below $70 per kWh. If prices continue to evolve as expected and hit 50 USD/kWh, I'm pretty sure I can get mine below that (non EV grade) as part of the deal.

Of course, I would still use wood for heating - but it would mean I can stop running the generator altogether as well.

 

[upnorthandpersonal]

2500 usd per cycle or 2,5usd/kWh

Yeah, I'm not calculating it like that. It's the independence, but also the business opportunities that come with doing something like this. It'll pay for itself in no time.

 

[MattiFin]

Just need to modify the gasifyer - to allow wood gas to run your generator in the winter months, while it heats your place!

Wood gas operated generator, battery bank and large thermal storage would be pretty good match. Dumping power to battery and thermal storage woould allow the CHP to run at fixed output power, making it easier to operate when there is no need to throttle down.

 

[OffGridForGood]

I have done some wood gas experiments in the past,
but engines don't work with dirty fuels and lots of hands-on tinkering lead me to abandon this. too bad really, since were literally surrounded with wood.

 

[upnorthandpersonal]

I've investigated wood gas before. It's a pain to get to work correctly, and reliably + maintenance that comes with it. Something like the Volter 40 CHP consumes 4.5 m^3 of wood chips for 24 hours of operation, and you can't just turn it off and on when you need it (it should run all the time).

Cost of the Volter 40 is about 180k Euro, and then you need a dryer (40k Euro) etc. in addition.

 

[OffGridForGood]

ouch!
I tried some experiments using wood pellets as the fuel source, but they are too small really, they don't work as well as I had hoped.

 

[Zwy]

More battery capacity doesn’t require more solar.
As long as you are producing more than you are using.
The batteries will get charged, just might take longer to get to 100%.

Yes, that has been how I run my house 96.4% off grid. Members have wondered how I do it with 8.4Kw of panels. It is with a larger battery. https://diysolarforum.com/threads/get-a-big-battery.70751/ Might take 2 or 3 days to get back to 100%.

 

[740GLE]

I've investigated wood gas before. It's a pain to get to work correctly, and reliably + maintenance that comes with it. Something like the Volter 40 CHP consumes 4.5 m^3 of wood chips for 24 hours of operation, and you can't just turn it off and on when you need it (it should run all the time).

Cost of the Volter 40 is about 180k Euro, and then you need a dryer (40k Euro) etc. in addition.

This Volter seems a big excessive for single home use, you have a small community or apartment building?

 

[upnorthandpersonal]

This Volter seems a big excessive for single home use, you have a small community or apartment building?

It's used in farms etc. as well where you can use the heat for greenhouses and other processes. For example (not Volter):

 

[Stormsoul]

Not fun in the way I want to do it for others, lol. I am a sparky I get my fill of electrical work everyday, and have a side business also. I do like helping others. I recently helped a co worker out planning his system and start up.

Man i wish you lived in AZ. I am saving for phase 2. And would love the help.

 

[Brucey]

Which is why I'm seriously considering building a 1 MWh battery pack at the moment. The way cell prices are evolving, this shouldn't even be super expensive. I could use 10 kWh a day and bridge my winter even with zero solar coming in.

Was looking at Gobel pricing and looks like you could get the raw cells for 72 14kWh batteries for less than $63k excluding shipping. But at that qty I'm sure they'd prob throw in free shipping on a container.

 

[740GLE]

How close were you from hitting “buy now” button?

 

[OffGridForGood]

20-foot standard shipping container, 28,200kg payload limit, 33 cubic metre volume limit...
280Ah cell is 174 x 72 x 205 mm and weighs approx 5.42kg

By weight 28200kg limit / 5.42kg per cell = 5200 cells
By volume .174x.072x.205 = 0.002568 cu.m per cell 33cu.m/.002568 = 12,300 cells
Weight is the limiting factor

5200 cells / 1152 = 4.5MWh
Paying for an entire 20-foot shipping container to deliver only 1152 cells will be inefficient, should plan to build 4 megawatt ESS pack, using 4608 cells - and have eoungh room in the 20-foot shipping container for the 288 BMS's you will need !!

One 40-foot container as an ESS box, will fit 288 DIY packs stacked 8 highx18 stacks x one row on each side of the container with just enough room for a wide enough corridor for service and to pull them out of a rack.
Crazy that 4MWh would fit in a 40-foot seacan.
and cost $250,000 to buy the cells.

Lets see, 100 days of crappy winter weather, x 37kWh per day = 3700kWh = 3.7MWh so 4MWh is perfect! just need to find a spare $250k...and some heated space.

 

[Rednecktek]

Lets see, 100 days of crappy winter weather, x 37kWh per day = 3700kWh = 3.7MWh so 4MWh is perfect! just need to find a spare $250k...and some heated space.

Well hell, is that all? Let me check my couch cushions.

 

[timselectric]

I need to work more weekends. lol

 

[OffGridForGood]

288 packs, less the six I have already is 282 more...if I DIY one 304Ah 16s pack every spring and every fall...two packs per year..it will only take 141-years to build (and pay) for it.

 

[Stiffmeister]

Currently, I would be looking at cell cost of around 70k directly from EVE. However, I can get this lower. I'm involved with several projects that will need a ton of cells (multiple MWh packs). If these all go as planned, I'll be able to ship my cells as part of a very large order and will have them well below $70 per kWh. If prices continue to evolve as expected and hit 50 USD/kWh, I'm pretty sure I can get mine below that (non EV grade) as part of the deal.

Of course, I would still use wood for heating - but it would mean I can stop running the generator altogether as well.

I've been purchasing from James at 18650 store. Great prices at $100 each (May 24) but shipping cost for 64 is $1000. I live in Cabo San Lucas Mexico and between a long drive plus 19% duty tax....I need to figure out how to ship from China. Does everyone use Alibaba and is there an EVE direct? I see 304 cells for $65 on the website. Totally worth it to tow my cargo trailer to a shipping port (Mexico sells JUNK solar).

 

[upnorthandpersonal]

Does everyone use Alibaba

If you're new to this game (Icoterms etc.), yes. Ask for DDP shipping, don't take anything else and they'll get delivered to you. If you only want delivery to port, you could check out other incoterms, but just be 100% sure you know what you're getting into.

 

[timselectric]

Cells are heavy and shipping gets expensive.
This is why I am happy to be able to pick mine up.
Of course it only makes sense for me once a year, when I am already driving right past the place. So I have to decide what I want each time. As it will be another year before I buy again.

 

[NCislander]

Same here. Makes more sense in my similar case to pickup cells from 18650 Battery store. 6 hour drive round trip.

 

[timselectric]

15 hr round trip for me.
So, it only makes sense when I'm already passing by.

 

[niktak11]

4 day round trip for me. I'll let FedEx do the driving.