01 / Direct answerEstimate full-load DC current by dividing AC power by battery voltage and inverter efficiency.
A useful planning formula is battery current (A) ≈ inverter AC output (W) ÷ battery voltage (V) ÷ conversion efficiency. At 51.2 V nominal and an assumed 90% efficiency, a 5 kW AC load is about 108.5 A DC, while a 10 kW AC load is about 217 A DC.
These are planning estimates, not equipment ratings. Real battery voltage changes with state of charge and load, inverter efficiency changes with operating point, and surge power can require substantially more current for a short period.
5 kW inverter load
Approximately 108.5 A at 51.2 V and 90% assumed efficiency.
10 kW inverter load
Approximately 217.0 A at 51.2 V and 90% assumed efficiency.
16.8 kW inverter load
Approximately 364.6 A at 51.2 V and 90% assumed efficiency.
Planning current for common inverter power classes.
The table below assumes the inverter is delivering its stated AC power continuously, the battery is at 51.2 V and conversion efficiency is 90%. Use the selected inverter's published DC data and the battery's full operating-voltage range for final engineering.
5 / 6 kW
About 108.5 A / 130.2 A DC.
8 / 10 kW
About 173.6 A / 217.0 A DC.
12 / 15 kW
About 260.4 A / 325.5 A DC.
Design for the operating-voltage range, not only the 51.2 V label.
Current increases when battery voltage falls. For example, the same 10 kW output at 48 V and 90% assumed efficiency is about 231.5 A, compared with about 217.0 A at 51.2 V. Cables, busbars, fuses, breakers and battery current limits must be checked at the applicable design condition.
Nominal voltage
Useful for comparison and first calculations, but not the lowest operating voltage.
Low-voltage condition
Can create the highest continuous current for a given AC power.
Protection
Select cable and protective-device ratings from the confirmed equipment and installation rules.
Compare estimated demand with the battery's continuous and peak limits.
SAVYEN's public 51.2 V battery data lists maximum discharge values of 100 A for the 5.12 kWh 100 Ah model, 200 A for the 16.08 kWh 314 Ah model and 300 A for the 32.15 kWh 628 Ah model. Those figures must not be treated as automatic inverter compatibility.
The estimated full-load current, starting surge, charge current, BMS protection behavior, communication protocol, firmware, cable arrangement, parallel rules and required operating margin all need written confirmation for the exact battery and inverter pair.
100 Ah model
Public maximum discharge: 100 A; confirm the continuous operating limit and intended inverter load.
314 Ah model
Public charge/discharge value: 200 A; confirm current duration and exact system configuration.
628 Ah model
Public maximum charge/discharge: 300 A; confirm the final inverter, protection and communication match.
Parallel units may share current only in an approved system design.
Do not assume that connecting two batteries automatically doubles every limit. The battery manufacturer must permit the quantity, and the system needs compatible BMS addressing, equal-current cable design, individual and common protection, communication settings and a documented commissioning procedure.
Current sharing
Depends on cable resistance, state of charge, battery condition and BMS behavior.
Energy expansion
Parallel batteries increase nominal kWh, but power capability still requires confirmation.
Commissioning
Verify addresses, firmware, communication, protection and balanced current before operation.
Confirm these values before approving the inverter and battery pair.
Provide the exact inverter and battery models, continuous and surge loads, phase, AC voltage, battery operating range, charge and discharge current limits, BMS protocol, firmware, number of batteries, cable length, protection and installation conditions.
Power
Continuous AC output, surge magnitude and surge duration.
Battery
Voltage window, continuous and peak current, usable energy and parallel limit.
Communication
CAN or RS485 protocol, pinout, firmware and approved settings.
Product data and related evidence.
Use these public sources to verify the model facts used in this guide. Final order specifications still require written confirmation.