The maximum charge rate varies based on the inverter model and the specific batteries used.
In simple terms, the charge rate is determined by multiplying the charge current by the battery voltage, resulting in a value measured in VA (or kW).
For example, the H1-G2 inverter has a maximum charge and discharge current of 40A. When paired with three ECS4300 batteries, which provide a nominal voltage of 172V, the theoretical maximum charge rate, assuming a power factor of 1, would be 6.88kW. However, since the H1-G2 inverter has a maximum output power limit of 3.68/5 or 6kW (depending on the model of H1-G2 installed), the actual charge rate will be constrained by this limitation.
Another example involves the KH10 inverter paired with an EP5 battery. With a maximum charge/discharge current of 50A and a nominal battery voltage of 192V, the theoretical charge rate would be 9.6kW. This value is slightly below the KH10 inverter’s maximum output capacity. However, battery voltage fluctuates based on the State of Charge (SoC), meaning the actual charge rate may vary. Additionally, users can manually adjust the battery charge current in the inverter settings.
For an accurate assessment of the maximum charge rate for your specific setup, refer to the relevant product datasheets.
Factors Influencing the Charge Rate:
- State of Charge (SoC): Battery voltage changes as the SoC fluctuates, affecting the charge rate.
- Temperature: High or low battery temperatures may trigger derating mechanisms, reducing charge rates to protect battery health.
- Charge Rate Throttling at High or Low SoC: When batteries are at very low or high SoC levels, the charge rate is intentionally reduced. This precaution prevents excessive stress on battery cells, reducing the risk of degradation and ensuring long-term battery performance.
