One other issue is the Charger used. The new WFCO's are switchable between LA (lead acid) and LI (lithium) and had to upgrade mine. Lithium's charge at 14.6-14.8v versus 13.8. I purchased two 100aH LiFePo4 for $310 each from Ali Express (Mr. Li's site). Received within 2 weeks. Included a LiFePo4 charger for each. Charges from 400w of solar. So far, so good.