Skip to main content
Battery system planning

Configure the battery, not just the kWh.

Turn a load requirement into a first-pass battery configuration with usable capacity, a design reserve, pack quantity and an estimated series-parallel layout.

Battery system configuration

What battery configuration covers the load?

Start with the demand, runtime and usable window. The calculator then adds a planning reserve and rounds the answer into a practical series-parallel battery layout.

Updates as you type
1
Set the energy requirementWhat the load needs during the event
2
Choose the battery building blocksCapacity, reserve and nominal DC voltage
Your first-pass configurationReady
12packsinstalled battery configuration
Load event40 kWh
Design nominal59.78 kWh
Installed61.44 kWh
Estimated layout1S × 12P51.2 V nominal string
Delivered usable energy45.22kWh
Capacity margin13%
Indicative C-rate0.08C
Voltage above target0%

The voltage estimate is close to the requested DC bus. Confirm inverter, BMS, current and protection limits before final selection.

iPlanning formula: required usable kWh = load × runtime; design nominal kWh = required usable kWh ÷ (DoD × efficiency) × (1 + reserve). Final battery design must confirm inverter voltage window, pack current, BMS limits, temperature and local protection requirements.

How the battery configuration is built

This calculator separates the load requirement from the physical configuration. First it works out the usable energy required by the load, then it applies the usable window, system losses and a planning reserve before assembling whole battery packs.

Load event
usable kWh = load kW × runtime h
e.g. 5 kW × 8 h = 40 kWh
Design capacity
nominal kWh = usable ÷ (DoD × efficiency) × (1 + reserve)
e.g. 40 ÷ (0.8 × 0.92) × 1.1 = 59.8 kWh
Pack quantity
minimum packs = ceil(design nominal ÷ pack kWh)
e.g. ceil(59.8 ÷ 5.12) = 12 packs
String layout
series = ceil(target V ÷ pack V); parallel = ceil(packs ÷ series)
e.g. 51.2 V packs at 204.8 V target = 4S

Use the result as a design brief

Required usable energy
The energy the load needs to receive during the requested runtime.
Design nominal energy
The nominal energy target after the usable battery window, losses and reserve are included.
Series × parallel
A first-pass configuration: series packs meet nominal voltage and parallel strings provide capacity.
Indicative C-rate
A quick power-to-energy signal. Confirm the actual pack current rating before final selection.

The result is a planning configuration, not an installation drawing. Final engineering must validate inverter DC voltage limits, BMS rules, current capability, temperature, protection and local electrical codes.

Need to reduce a grid peak?

Size power and energy around the peak profile

Use the Peak Shaving Calculator when the key input is a current and target site peak rather than a fixed backup load.

Open peak shaving

FAQ

What is the difference between this and a kWh estimate?

A kWh estimate answers the energy question. This tool goes one step further by applying a design reserve, rounding to complete packs and estimating an energy-level series-parallel configuration.

Why is the installed capacity higher than the minimum capacity?

A real system is assembled from whole battery packs and strings. The calculator rounds up for the requested design reserve and then rounds again to complete the required series-parallel layout.

Does the voltage result confirm inverter compatibility?

No. It is a first-pass nominal voltage estimate only. Confirm the inverter DC operating window, battery BMS limits, cable current, protection and site requirements before ordering equipment.

What design reserve should I use?

Use a small planning reserve when early-sizing a system. The final reserve should be set against battery aging, ambient temperature, duty cycle and the operating strategy for the site.

From first-pass plan to installed system

Share the configuration — we will check the assumptions

Hua Power can validate the voltage platform, reserve, battery current and product configuration before equipment is selected.

Intelligent energy storage systems deployed across 30 + countries since 2015.

Get in Touch