noeife evo 55 2v 58 8v 2 5a 3a lead acid battery charger for 48v lead acid battery cooling fan automatic shutoff greenDue to some batteries with M25 charging connectors that have integrated charging protocols, our charger cannot support batteries with built in charging protocols. Please confirm with the battery supplier before purchasing whether the battery has an integrated charging protocol. For M25 (2+1+5) and M25 (2+4), the standard polarity is 1+ for positive and 2 for negative. If you require a different polarity, please let us know. Contact: You can reach us