Below is reference guide to connect series vs parallel connection for batteries. For lithium batteries, please make sure the BMS is equipped to handle series or parallel connection.

Series Connection

The diagram above demonstrates “Series” connection for batteries. In series, the voltage is doubled to meet your application motor needs. For example, two 12V batteries connected in series will output 24V to your motor. 

To connect the battery in series, you should connect one side of the batteries from one red positive terminal (+) to black negative terminal (-) on the other battery. The remaining open terminals are to connect to your motor’s cabling.

Parallel Connection

The diagram above demonstrates “Parallel” connection for batteries. In parallel, the amp hour is doubled to extend your battery capacity. For example, two 12V 25Ah batteries connected in parallel will output 12V 50Ah to your motor. 

To connect the battery in parallel, you should connect one side of the batteries from one red positive terminal (+) to red positive terminal (+) on the other battery and same for the black negative (-) terminals on each battery. Then connect your motor to one battery’s positive and negative terminals.