Sam’s Club has a new perk for electric vehicle (EV) drivers. And, while it’s not going to make someone drive across town to join the Walmart-owned brand over its rival, it might help people decide when both chains are in similar locations relative to where they live. Sam’s Club has a new offer with its credit card partner, Synchrony (SYF) – Get Synchrony Financial Report that should appeal to EV drivers. As of May, any Sam’s Club member who also holds the warehouse club’s signature Mastercard will earn 5% back in Sam’s Cash on EV charges at eligible EV charging stations in the United States. During “a special electric vehicle charging promotion,” cardholders will earn an additional 5 percent back on EV charges for a total of 10% back in Sam’s Cash for the entire month of May.