San Francisco-based startup Fenix International, which makes a battery product that can charge cell phones and run lights in off-the-grid regions, has scored its largest deal to date with Vodafone in Tanzania. The telecom giant will sell Fenix’s ReadySet charger and its accompanying charging accessories in Tanzania, market the products via billboards and television spots in the region, and also create a fund to make loans to women entrepreneurs so they can buy the product.