Nominal voltage calculator

Build a battery pack from cells, then see its nominal voltage, its voltage range, its nominal energy and the current for a load.

Read this first. The two presets use values from the Victron 12.8 V and Sunsynk L3.0 sheets named on the page. The Sunsynk cell count (16) is inferred from 51.2 ÷ 3.2 because the sheet does not state it. The load and the inverter window defaults are invented. Read real limits from the maker's documents. Use a dot for decimals; "10,000" is read as ten thousand.

Presets:

Pack

Cells in series (whole number) Cell nominal voltage (V) Lowest cell voltage you will allow (V) Highest cell voltage you will allow (V) Pack capacity (Ah)

Load and inverter

Load on the battery (W, not kW) Inverter DC window, lowest (V) Inverter DC window, highest (V)

Results

Result	Value
Pack nominal voltage (cells × cell nominal)	-
Lowest and highest pack voltage	-
Range against the label	-
Nominal energy (nominal V × Ah)	-
Current at the lowest voltage	-
Current at nominal	-
Current at the highest voltage	-
Inside the inverter DC window?	-

Start cable and fuse sums from the current at the lowest voltage, not the nominal, then apply the maker's limits and your code's rules. Nominal energy is a label figure, not usable energy.

Method: nominal V = cells × cell nominal V. Nominal Wh = nominal V × Ah. Current = load W ÷ pack V. The window test needs the lowest pack voltage at or above the window's lowest value and the highest pack voltage at or below its highest value.