18650 Battery Pack Builder

Balance your cells into even series groups based on capacity and internal resistance. Paste your cell data and get an optimized layout.

Step 1

Load clean cell data

Paste values or import a CSV, then choose whether you are balancing by capacity, IR, or both.

Step 2

Decide on your series and parallel count, then confirm the voltage assumptions for the finished pack.

Step 3

Inspect divergence, leftovers, and per-group values before you start physically assembling cells.

Target pack14S4P

Cells required56

Entries pasted0

1Cell data & balancing

Cells usedSalvaged cellsNew cells

Balancing method

Cell capacities

Use capacity values only to balance each series group.

Cell capacities with IR

Use capacity plus internal resistance together when assigning cells.

Internal resistance only

Balance purely by internal resistance values.

Enter a comma-separated list of cell capacities. Example: 3124,3110,3098,3088

CSV import is client-side. Your builder inputs stay in this browser until you clear them.

Number of seriesCells in parallelNominal cell voltageMinimum cell voltageMaximum cell voltage

2Pre-build checks

You are short 56 cells for the requested 14S4P pack.

No spare cells beyond the requested pack size.

Capacity-only balancing is fastest and usually enough for consistent new cells.