noeifevo 42v 2a 3a 3 5a 4a lithium charger for 10s 37v li ion lipo batteries cooling fan automatic shutdown redDue 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 purchase 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 information: You can