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