【Modular Flexibility with 4-Cell Design】 Built using 4 high-quality Winston cells, this 12V 50Ah pack is ideal for users seeking scalable, DIY-friendly energy solutions. Easily expand capacity by adding units in parallel — no complex system rewiring needed. 【Advanced LiFeYPO₄ with Yttrium – Safer & Smarter】 Uses next-gen LiFeYPO₄ chemistry enhanced with yttrium, delivering superior stability, better thermal resistance, and longer life than standard LiFePO₄. 【Perfect for Solar, Off-Grid & Trailer Power】 A popular choice among solar and mobile power users. The pack provides high output power, even more than needed in many use cases—perfect for inverters, solar banks, or trailer power systems. 【Easily Expandable Setup】 Customers love the expandability: start with one pack, then scale up to double or triple capacity just by connecting more cells in parallel. No need to replace the system as your power demand grows. 【Lightweight & Efficient】 Lighter and more compact than equivalent lead-acid batteries. A better bang for your buck with long cycle life and eco-friendly materials. 【Trusted Quality Backed by Real Users】 Highly rated for reliability, environmental safety, and ease of integration into custom systems. Customers highlight the long cycle life, flexible configuration, and clean energy profile. TSWB-LYP50AHA cell is lithium ion cell, the cargo contains 4 pcs of 50ah cell to make a 12V battery pack can unlimited DIY expansion. The accessories copper connector and bolts & washers are all included in the carton. TSWB cells have below main advantages: 1. High safety not easy to explode 2.Large capacity 3. Long lifespan 4.Green and environment friendly 5. Mature technology in line with IATF16949 6.Low self-discharge (about 1%/month) 7. Wider operation temperature of -45 to 85℃ For more information, pls visit Thunder Sky Winston battery website.