https://www.ebay.com/itm/1261615570...customid=4f96aa4476b911ef9516b6f36fdc52ea0INT 12-Volt 280AH Eco-Worthy LiFePo4 Lithium Iron Phosphate Battery w/ 6000 Cycles on sale for $479.99 - 20% off when you apply promo code FALL20OFF at checkout = $383.99. Shipping is free.