Battery Bank Series-Parallel Configuration Planner — Build the Required Bank
Determine how many batteries must be connected in series and parallel to reach a target DC voltage and energy requirement.
Battery bank inputs
How series and parallel connections change a battery bank
Series connections increase voltage while keeping amp-hour capacity approximately equal. Parallel strings increase amp-hour capacity while keeping string voltage approximately equal.
Series count
Required series batteries equal system voltage divided by single-battery voltage. A fractional series count is not physically possible, so the tool requires a whole-number match.
Parallel count
Once the correct string voltage is established, usable energy per string can be calculated and compared with the required energy.
Why discharge limits matter
A battery's nominal energy is not necessarily all usable. The selected depth of discharge reduces the available energy before the bank reaches the chosen planning floor.
Limitations
Actual bank design may be constrained by maximum charge/discharge current, battery type, balancing, thermal conditions and manufacturer's allowable combinations.
Frequently asked questions
Can system voltage be lower than one battery?
Yes mathematically, but the tool will flag an incompatible series ratio rather than inventing a wiring arrangement.
Does parallel connection change voltage?
For matched batteries, parallel strings retain the string voltage.
Can the required energy be zero?
Yes. The resulting parallel requirement is one string because the bank still needs the target voltage.