Server Rack Battery vs DIY

[rodrick]

here’s where I got them from

USA STOCK CATL 3.2V 280Ah 3.2V LiFePO4 6000cycles True capacity 285-305Ah Prismatic Battery Cell Laser Welded Terminal Stud

This product link for USA stock PRESELL( shipment on the way to Houston, can ship out 2-3 weeks), Unit price for single battery(MOQ is 4pcs), FAST UPS Shipping Continental United States ONLY, If you come from others or want ship by sea to save cost then please click Contact to sen

www.docanpower.com

 

[Checkthisout]

here’s where I got them from

USA STOCK CATL 3.2V 280Ah 3.2V LiFePO4 6000cycles True capacity 285-305Ah Prismatic Battery Cell Laser Welded Terminal Stud

This product link for USA stock PRESELL( shipment on the way to Houston, can ship out 2-3 weeks), Unit price for single battery(MOQ is 4pcs), FAST UPS Shipping Continental United States ONLY, If you come from others or want ship by sea to save cost then please click Contact to sen

www.docanpower.com

How much was shipping?

 

[rodrick]

How much was shipping?

It’s included at that price

 

[Texican]

seems like if you are not adding a container/box like seplos, you are not comparing the same thing
what the comparison with a simliar box to eg4 ?

 

[houseofancients]

seems like if you are not adding a container/box like seplos, you are not comparing the same thing
what the comparison with a simliar box to eg4 ?

which is why i posted my 2 cents

 

[rodrick]

I’m putting everything in a 6x8 well insulated stand alone building on custom built racking with fire protection divisions between banks I don’t like all of my batteries stacked on top of each other just in case

 

[iamrich]

So no links??

If you guys would just post links that would be sooooo much better.

DOCAN POWER

Delivering Outstanding Capacity And Nobility Power & Trustworthy Partner for Solar LiFePO4 BatteriesDocan is TOP10 battery and battery suppliers in China. We supply TOP1 service of Lifepo4 Prismatic Cell and Battery Pack for variouse area, 12 years+ focus on high capacity, high wattage, high...

www.docanpower.com

 

[Checkthisout]

Ok. How about a link to the 14 cents per wh batteries?

 

[bfitzgerald]

I went DIY. I just received my 17 EVE 280 cells from Gobel Power (China). They arrived in just over 2 months with half of that time held up by Canada Customs. The batteries are Genuine B Grade cells (no such term as Genuine) but Gobel clearly states that they have the EVE grade B on the QR code, and that's what I received. The cells appear to be brand new, are not bloated, and as promised arrived with matched voltage and I.R. The Gobel grade of battery was HSEV or LSEV. (High Speed Electric Vehicle vs. Low Speed Electric Vehicle). Costs $5 more per HSEV battery and I think that is the cost for testing and sorting batteries into better matched sets. All except one of my cells arrived at 3.304v with one at 3.303v. Close enough. I haven't done an I.R. test yet, but all are labeled as less than than .25 mOhm. I just completed the first capacity cycle test using a ZKETECK EBC-40L tester and I am very happy to say that it came out to 282.30 ah. I will test a few more to make sure it wasn't just luck of the draw.

I ordered directly from Gobel's website (not through Alibaba) and chose to pay by credit card and pay the credit card fee of $107.45. I get around 1% cash back on the card so it only cost me about $75 to use the card. The sales rep I dealt with was Ellie and she was very good at keeping me updated or answering my questions. Depending on the outcome of the capacity tests I would not hesitate to use Gobel Power again and/or recommend them to friends.

I choose to buy 17 cells for a couple of reasons. First is that I plan to parallel the LiFePo4 battery with FLAs (there is a thread on this). The battery voltages are a better match between a 17s LFP battery and FLA batteries but neither is perfect. I could still choose to go 16s and I would then have a spare cell (reason #2). I paid extra for a 24s BMS with Bluetooth because I wanted Bluetooth capability and, of course, the ability to make a 17s battery.

The bottom line below is what I paid, DDP to my door. Yes, I will have to spend a few bucks to add this to my system, but no matter what you buy, either DIY of factory built, there will be some adaptation costs. So the math says $167.21/kwh plus a couple of hundred bucks for the battery build components. I also bought the ZKETECH tester which I didn't price into the cost per kwh. This isn't likely to be my last build so I will write the $150 off over a few builds.

• 1 × JK 15S ~ 24S 150A Smart BMS 2A Active Balance With GPS Port Comm
• Discharge Current: 150A
• RS485/CAN: RS485 Port

• US$140.00

• 20 × Various Size Epoxy Sheet Glass Fiber Mats Separator for DIY Lith
• for Model: EVE LF280

• US$4.00

• 17 × EVE 3.2V 280Ah Rechargeable LiFePO4 Battery Cell
• Busbars and Bolts: Included
• Grade: LSEV
• QR Intact: B Mark
• Matched IR: Yes
• Matched Voltage: Yes

• US$1,870.00

---

Sub-Total : US$2,014.00
Sea Freight (Tax Prepaid DDP Terms) (Shipping to CA): US$428.12
Payment Fee (4.4%): US$107.45

Grand Total : US$2,549.57

So to DIY or not DIY? Most issues have been well debated here and elsewhere. I like to understand how and why things work. You can read a book, or watch a video but I want to really understand what I have and how to maintain and, if necessary (and possible), repair it. If that's not YOU, buy a ready made solution from someone who you trust to support you. If you don't get that support, including great warranty support, you may as well do it yourself. Price is only one factor.

 

[EastTexCowboy]

Don't forget Shipping in both cases.

To WA state, sig solar charges $300.00 to ship 1 battery or two (might be the same for more) so in my case I calculated for two batteries and get like 29 cents a Wh.

Or 23 cents for Diy.

That's why I want to know where these guys are getting the raw cells for 30% less than what I was just quoted.

Good point. I think I caught a special on shipping on the last two I ordered from Signature Solar. I see Docan has a warehouse in Houston. I'm only about 1.5 hours away. I wonder if they will let you pick up at their warehouse and save the shipping costs?

 

[houseofancients]

Good point. I think I caught a special on shipping on the last two I ordered from Signature Solar. I see Docan has a warehouse in Houston. I'm only about 1.5 hours away. I wonder if they will let you pick up at their warehouse and save the shipping costs?

they will, but the prices for cells in houston are incl. shipping as far as i know

 

[SolaroSsaurius]

I did both, first bought a couple server racks to get my solar up and running,
then as I learned from others, and got my courage up, ordered 280Ah cells on Alibaba's (pay and pray) system and built my first DIY rack battery.
Let it run a few months and checked all cells were withing 3-millivolts so ordered more cells and built my second DIY rack battery. Repeat, cells stayed within a few millivolts of each other, so...
Now have my third set of cells on order, will be in by end of Feb.
I like to learn by doing, and take things one step at a time, and test/see if it works well. No problems so I built more. Not everyone is going to be comfortable to build their own battery, or be patient enough to wait for the cells. To each their own I say.
Cost-wise, the 280Ah cells cost about $1900 USD shipped, a BMS with active Balancer is about $70, through-wall battery terminals in 200A are $30, and a decent 2P 125A DC rated breaker for the battery is another $30, some wire and build your own case or set it up open on a shelf if you like. $750/100Ah approx cost. about half the cost of a factory finished rack battery in a nice case, perhaps more easily serviced. I like what I have learned doing my own. Like ET Cowboy, I like to build stuff becase I can more than becase of the money, the more I build the more I understand. If these last 10 years they did me well.

Hi!

I'm having a hard time getting a decent breaker.

What have you used?

Thanks in advance

 

[SolaroSsaurius]

the 304 cells i ordered from china came to 109 usd per cell, same cell from a ( somewhat) local warehouse 149 usd

this isnt that hard to understand now is it ?

on a side note, i would very seriously consider on skipping the 280k cells, as most , if not all dont seems to live up to their specs, and may even be downrated 304 cells

As I,'m in the process of accessing a new set of cells, could you please share the brand and source for yours?

Thanks in advance

 

[iamrich]

Ok. How about a link to the 14 cents per wh batteries?

Same site, but direct from China and wait the 2-3 months. They have several options at $0.15 wh for x16. If you buy enough, you might be able to get the shipping down the extra $0.01.

 

[Checkthisout]

What about these? Got 8 of them in my cart.

EVE LF304 Grade B Cells - 3.2V LiFePO4 304Ah Battery

Price is per battery Grade B Cells - Original QR code is marked up and unreadable. BRAND NEW CELLS - Capacity tested - sorted and matched. Guaranteed to pull 304Ah+ We test all cells (IR, Voltage, Capacity, Visual inspection) returning anything that does not pull above capacity or has any other...

www.18650batterystore.com

 

[PreppenWolf]

My build thread with 260Ah cells for $61 each in large volume, $72 each in low volume. 60 days for delivery. It was roughly $80 per cell shipped.

Keheng 260ah 250ah Battery Lithium Ion Lifepo4 3.2v Battery Prismat Battery Cell - Buy Byd 3.2v 260ah Lithium Ion Batteries Electric Battery Energy,Lifepo4 Power Supply Rechargeable Iron Phosphate Batterie Cell Lipo Ups Battery,Prices Bateria Prismat

Keheng 260ah 250ah Battery Lithium Ion Lifepo4 3.2v Battery Prismat Battery Cell - Buy Byd 3.2v 260ah Lithium Ion Batteries Electric Battery Energy,Lifepo4 Power Supply Rechargeable Iron Phosphate Batterie Cell Lipo Ups Battery,Prices Bateria Prismatic Cells Li De Litio Lifepo4 Li-ion Para...

m.alibaba.com

EG4 6500EX 120/240 Setup, 48V 105kWh Battery & Overkill 100A BMS Install

diysolarforum.com

 

[OffGridForGood]

Hi!

I'm having a hard time getting a decent breaker.

What have you used?

Thanks in advance

To be clear: In my set up I installed a 2P 125A DC rated breaker in the battery (ie in each of five separate batteries that make up the rack) then from each postitive to a MCCB 1P 125A DC rated breaker to a Class T 125A fuse, and from the fuse to the 600A copper bus bar.
In each DIY battery I used a 125A 2P Tomzn DC rated breaker - this is my way to totally isolate the battery if I want to remove it from the rack while the rest of the rack remain in service. This is the Tomzn model TOB1Z-125 and is available on alibaba - if you buy a few at a time the shipping is a lot less per unit. My first one has been in service for about 1.5 years now. All good.
For the 1P positive breaker between the Pos on the battery and the T-Class I used a MCCB Tomzn TOM7Z-250 1P this is a moulded case breaker not a mini circuit breaker. Also available from aliexpress - IIRC these were about 36-40 bucks each. I use this to disconnect the battery while the battery remains "on" so I can check things like the battery total resting voltage or cell voltages with the battery isolated from the rack, but still on, just not sending or recieving any current from the PV or affected by the other batteries, by isolating the pos.
The T-class fuse between this breaker and the copper 600A bus bar in the rack case is my ultimate protection from a dead short. I put a T-class 125A fuse on every battery between the pos bus and the pos disconnect. Then from the both pos and neg bus to the Inverters, I have a smaller (I mean shorter) bus bar and 300A T-Class fuse (one on Pos, one on Neg) - my system has a max of 13,100W peak output, at 48 volts DC, ie 273A, and is supplied with five batteries each set to max 100A to a main bus bar.

 

[SolaroSsaurius]

To be clear: In my set up I installed a 2P 125A DC rated breaker in the battery (ie in each of five separate batteries that make up the rack) then from each postitive to a MCCB 1P 125A DC rated breaker to a Class T 125A fuse, and from the fuse to the 600A copper bus bar.
In each DIY battery I used a 125A 2P Tomzn DC rated breaker - this is my way to totally isolate the battery if I want to remove it from the rack while the rest of the rack remain in service. This is the Tomzn model TOB1Z-125 and is available on alibaba - if you buy a few at a time the shipping is a lot less per unit. My first one has been in service for about 1.5 years now. All good.
For the 1P positive breaker between the Pos on the battery and the T-Class I used a MCCB Tomzn TOM7Z-250 1P this is a moulded case breaker not a mini circuit breaker. Also available from aliexpress - IIRC these were about 16-20 bucks each. I use this to disconnect the battery while the battery remains "on" so I can check things like the battery total resting voltage or cell voltages with the battery isolated from the rack, but still on, just not sending or recieving any current from the PV or affected by the other batteries, by isolating the pos.
The T-class fuse between this breaker and the copper 600A bus bar in the rack case is my ultimate protection from a dead short. I put a T-class 125A fuse on every battery between the pos bus and the pos disconnect. Then from the both pos and neg bus to the Inverters, I have a smaller bus bar and 300A T-Class fuse (one on Pos, one on Neg) - my system has a max of 13,100W peak output, at 48 volts DC, ie 273A, and is supplied with five batteries each set to max 100A to a main bus bar.

Thank you very much for the detailed information.
I'll cross your breakers' reference # and confirm that they are all non polarized, as those prices seem quite interesting.

Again, thanks!!

 

[OffGridForGood]

and confirm that they are all non polarized

Report back either way, it would be good to know!
Edit: at the time I purchased the Tomzn breakers, the marketing information indicated 'non-polarized', but to be honest I never found a proper technical manual to verify this. I installed the 2P MCB in the DIY batteries using the primary direction as 'out of the battery' - this could be up to 100A if my system was outputting max while two batteries were off-line; while the input, ie charging the battery - would be far lower amperage and normally split between 5 batteries. Charging by grid/generator is 30A.240vAC >7200W > 30A 48vDC per battery, and my max PV input is about the same (7kW).
Ditto the 1P MCCB on the POS is set (Line/Load) to support the primary direction as out of the battery, in my thinking this is the higher risk flow direction.
The T-Class 125A fuses are not directional, and I rely on these for my ultimate protection in either direction. Being hard to come by, I installed the 125A T-Class fuses only on the pos side between the 1P MCCB and the Rack Main Bus, I had planned to ALSO install T-Class fuses on the NEG side of each battery but was not able to source them at the time.
After the main Rack Buses, I feed a smaller 300A bus on the wall below each inverter, and each (Pos and Neg) have 300A T-Class fuses at this location as my ultimate protection against a dead short between the inverter and the ESS Rack.
Hope this all makes sense.

 

[OffGridForGood]

Ultimately the DIY Batteries can be fun, a learning experience, and can save a bit of money, a bit more so if you are happy with a simple DIY case (or no case at all) but no warranty.
Both of my Factory Built Server Rack Batteries have a warranty. Hope I never need it. LOL.