https://www.ebay.com/itm/1271883731...customid=145cb4b0723e11f08196beced35bb4e30INT 2-Pack ECO-WORTHY 14kWh 48V 280AH LiFePO4 Solar Battery Vertical Standing Backup on sale for $4219.49 - $350 with coupon code FIFTEENFORYOU at checkout = $3869.49. Shipping is free.