12V requires 4 cells, 1 BMS and 1 fuse.
From Luyuan Tech:
(DDP Duties taxes paid, delivered to the door USA.)
4pcs EVE 3.2V 280AH New Version Genuine Grade A Lifepo4 Battery Cells
Fully Matched for Solar System EV RV.
X2 for 8 cells:
US $1,438.00 DDP
https://www.alibaba.com/product-detail/4pcs-EVE-3-2V-280AH-New_1600191395276.html?
1 Pcs 3.2V 280Ah Rechargeable Iron Lithium Battery Lifepo4.
(Bulk Commodity cells)
8 cells:
US $1,230.00 DDP
Luyuan 1pcs 280ah Lifepo4 (lfp) 3.2v Cells Battery (bulk,Capacity&voltage & Ir Matched )---new Version With 6000cycles - Buy Lithium Iron Battery battery Lifepo4 rechargeable Battery Product on Alibaba.com
www.alibaba.com
** For Luyuan, to get accurate shipping pricing, a chat in messenger is required.
Overkill JBD 4s BMS 120a LifePo4 Battery Management System for 12v DIY Batteries, Programmable, Bluetooth Included.
$113.00 – $149.00 USD ships from USA.
would require two, one for each 12V pack
overkillsolar.com
BlueSea "Bussman brand" MRBF Fuse with Fuse Block, $37, (Bay Marine Amazon)
require two, one for each 12V pack.
Casing / Battery Box ? many options & possibilities.
When you work out the numbers, DIY can save a pile of loot ! You also gain the knowledge of how it's all put together and how it should work as you study up a bit. It is NOT for everyone because it can become detailed with a high learning curve, requiring extensive Patience.
There are Known Good preassembled batteries which are available that are discussed on the forum.
Tale your time, do research here for KNOWN GOOD vendors, suppliers & products and Most Importantly, DO NOT Impulse Buy ANYTHING !
Hope it helps, Good Luck