You are correct.
You connect battery cells in series to increase the voltage.
You connect battery cells in parallel to increase current capability.
There is no problem with either series or parallel connection.
Rules About Battery Configurations
When configuring batteries in Series or Parallel; batteries should match Voltage, Capacity, State of Charge and Relative Age for safety and best performance.
Series - In Series configuration or series leg of series/parallel configuration, batteries should be as identical as possible.
Parallel - In Parallel configuration or parallel legs of series/parallel configuration, battery voltages MUST be identical, but battery capacity, state of charge, and relative age can vary moderately from one parallel leg to another.
Connection Engine Cranking Batteries the CCA (cold cranking amps) are multiplied by the number of parallel connections. This is also true with amp-hour capacity in deep cycle application.