https://www.ebay.com/itm/126557369610?toolid=10001&customid=d084827c9c0a11ef8298562d90c888120INT 2-Pack Eco-Worthy 12V 10Ah 256wH Lithium LiFePO4 Battery Deep Cycle for UPS on sale for $69.99 - $14 (20%) off when you apply coupon code TOPGIFTS20 on the checkout page = $55.99. Shipping is free.