My 280Ahr 16S battery experience

[OffGridForGood]

My off grid solar system is designed to be built in stages. The first stage had one MPP 6048 inverter and one SS 100Ahr 16S battery.
Next stage added another inverter and another 100Ahr battery (Solar Parts Store Canada) and first roof top PV.
Now into the third stage, expanding upon the roof top PV and Batteries: now building my own battery packs.
Using Alibaba, I searched many suppliers for the cells, and separated out the manufactures from the resellers, and always holding out the carrot of more sales in the future after a test set of 16 are shipped and pass capacity testing...and always using door to door shipping to see the full-shipped costs up front.
I reviewed purchasing ready made server racks in 100Ahr 150Ahr 200Ahr capacities, but the weight always resulted in high cost shipping/ high cost per 100Ahr.
So I decided to go with cells.
Shipping cells in boxes of two or four units significantly reduced total shipping costs, since the weight per box is low, and truck freight is not required.
Early on it became clear that shipping four 280Ahr cells was not much more expensive than shipping four 100Ahr cells. Cost per delivered Ahr was best with the higher capacity 280Ahr cells.
I was interested in the Seplos cases, but while these are very well made, their BMS issues and the cost of the kit & shipping was just too high to for me to justify.
I have a woodworking shop, so making Birch ply cases was a low cost easy solution in my situation. I built the cases to match the SS width of 17-5/16" so I would be able to make a suitable rack to hold the ultimate five packs I have in mind. (280 cases are 10"H 17-5/16"W 27"L overall size including plywood thickness).
Aliexpress had good options for low cost through-case terminals, and I ended up chosing 300A terminals not for their high capacity so much as the dimesions worked well to pass through 16mm (5/8") birch plywood and still have enough length of the bus exposed to connect wire ring terminals.
For a main battery breaker I went with Tomzn 2-P 125A DC rated breaker, these are DIN rail mount, and capable of up to 600VDC.
The final result is a good solid unit and the costs: (USD)
Cells with bus bars and ss nuts washers $90 ea x 16 = $1440 Alibaba
Shipped Door to Door = $480 arranged by Alibaba duty all in.
BMS JK shipped = $86 Aliexpress
Thru Case Terminals 300A = $22 Aliexpress Renhao Weiye Technology
Tomzn 125A DC 2-P breaker = $23 Aliexpress
Birch plywood for the case + hardware = $40 Local supplier
Wire & ring terminals = 60 Aliexpress/local electrical wholesale
Total cost of $2,151 for a 280Ahr 16S 48VDC pack (cost per 100Ah = $768.21, cost per W-hr =15 cents) USD. (about half the best price I could find on complete server rack battery pack ready made, and $700 cheaper than the Seplos-Mason 280A case/shipped. Labour: cutting and assembly time 3hrs.
This is the best price point I have been able to find for my location and situation (stationary off-grid solar), and my second set of cells is due to arrive in a couple weeks.
Not for everyone, however I thought it worthwhile to share info, since the storage part of off-grid is the expensive part.

 

[Samsonite801]

Thanks for sharing your story, always cool to hear others' experiences and hurtles too

I noticed that the times I ordered more than four cells from China sellers, like 8 or 16 cells, they always shipped them in separate boxes of 4 cells anyways, since I think they must've started to figure out this was much easier to get FedEx or UPS to ship for them in the USA... I don't know if they all do that now or not.

 

[OffGridForGood]

I believe they have not 'All' figured it out, here is why: about half of the offers I recieved had very high shipping costs, and by 'high' I mean about double the best ones. If they had a good price per cell, but the shipping was putting them out of the running, I gave them a chance to do better and it was often noted as 'truck' freight costs were driving the prices up.
I think as you say, some have figured out that four boxes of 40 lbs can be moved by FedEx or UPS far cheaper than one single item of 160 lbs requiring truck freight/liftgate etc. {I also noticed, that using my business address was lower cost than using my residential address BTW}.
I feel there is one other added advantage to buying cells: four boxes of 40 lbs seem less likely to be damaged during shipping than a single larger box with a full ready-made server rack inside. The boxes of cells came packaged with pretty thick soft foam completely surrounding every cell, unlike the two complete server racks I purchased last year while much heavier were not really as well packaged, and had some clear signs that the package corners got bumped pretty hard during shipping. (the racks were okay in my case, but I could see the shipping was harder on those single heavy packages)
One last thought: If one box of cells out of four ordered actually was damaged, they only need to ship one new 40 lb box out (perhaps just one cell even), while a server rack if damaged during shipping - well yeah, that is the whole unit going back and shipping a complete 160lbs again.

 

[Samsonite801]

It's also safer to ship smaller packages (as they can be better packed for the contents to stay secure.

Back when I was younger and stupider (hehe), I was working as a datacenter lab admin for a large corp, and I had to ship out a bunch of old SLA UPS batteries back to a recycler, I didn't know any better.

I put them all on a single pallet all inside boxes so you couldn't know what was inside (I didn't know anything about the hazmat rules and didn't put hazmat warning stickers on them, and didn't think to discharge them completely flat first).

Well, somehow (hehe), the straps broke or something and FedEx said they started on fire (shorted out somehow) in one of their transfer centers, they had sent me pictures of the whole pallet and contents all melted down... Woops...

The shipment I had prepared was bulky, heavy, and cumbersome. I did learn some lessons there, glad it didn't burn their building down, and nobody got hurt.

 

[OffGridForGood]

Wow - what an experience!
The boxes I have all came with DGD stickers and I was a bit surprised, as I wondered if the lower cost shipping was just the sellers 'forgetting' the proper warning labels, but as you say, it seems to be the weight. Courier-style delivery vs Truck Freight, 4 separate 40 lb boxes ship cheaper than one 160 lb crate.
I am sure for sellers like Signature Solar they can order a seacan load of server rack units and get better rates for a full seacan shipped multi-modal directly from a factory to their facility, very little handling required, and no danger of damage to the rack batteries in a shipping container I expect