LiPo solar storage batteries store best in a dry environment 40 to 80 degrees Fahrenheit and at a 50% charge. You should also cycle them every six months. It’s best to check with the manufacturer for their advice. Lithium batteries like to cycle and not just sit especially sitting in a fully charged state. That is why they are a good choice for off-grid solar where they can cycle in a 40 to 80% charge state for the best cycle life. They excel as a “partial state of charge” storage system. For backup emergency power systems, where they may sit for months fully charged lead-acid AGM batteries make a better choice.