https://www.ebay.com/itm/1260361290...=5337259887&toolid=10001&customid=6459ea0672e ECO-WORTHY 3584Wh 12V/280Ah Smart LiFePO4 Battery w/ Bluetooth Monitoring on sale for $376.45 - 15% when you apply code FIFTEENFORYOU in cart = $319.98. Shipping is free.