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Battery storage systems rarely follow exactly the same operating pattern from morning to night. Solar production changes with weather and daylight, electrical demand varies with production schedules or household activity, and the battery may need to switch between charging, discharging, and standby conditions.

For this reason, battery control based on a single daily schedule may not always match the actual energy profile of a site. The Three Phase Hybrid Inverter provides six configurable time periods for battery charging and discharging, giving system designers more flexibility when organizing daily energy flows.

Rather than applying one charging or discharging instruction to an entire day, the available periods can be arranged around different load, PV generation, and energy-storage conditions.

Why Time-Based Battery Control Can Be Useful

A solar-plus-storage installation can experience several distinct operating stages during one day.

In the morning, PV generation may still be limited while the electrical load has already started. Around midday, solar production can become much stronger and may cover the load while providing additional energy for battery charging. Later in the afternoon, PV output begins to decrease, while some facilities continue operating at a relatively high load. Evening operation can then create another period when stored energy may be useful.

A fixed schedule does not always represent these transitions accurately.

The six-period function allows battery operation to be divided into several defined windows. Each window can be associated with a specific operating condition instead of treating the entire day as one continuous charging or discharging cycle.

The actual schedule should be based on the site's load profile, PV production, battery specifications, operating mode, and applicable electrical requirements.

Understanding the Six Time Periods

The six periods can be considered separate sections within the battery-management schedule.

A typical installation might organize them in a sequence such as:

• Morning battery charging

• Daytime PV and load management

• Additional charging during a period of available energy

• Afternoon battery discharge

• Evening battery discharge

• Nighttime standby or another defined operating condition

This is only an example. There is no requirement for every project to use all six periods in the same way.

For a facility with significant differences between production hours, evening demand, and overnight consumption, multiple time windows can make the battery strategy easier to align with actual operating conditions.

The main advantage is flexibility. The schedule can be adjusted when the energy pattern of the site changes rather than being locked into one daily battery command.

Coordinating Battery Scheduling with PV Generation

Battery scheduling should be considered together with solar generation rather than as an independent function.

For example, the JUNCESS JIL-12kW-EP-D, JIL-15kW-EP-D and JIL-20kW-EP-D models have maximum PV input powers of 24 kW, 28.8 kW and 32 kW respectively. The supported PV input voltage range is 160–800 V, with the applicable MPPT range varying by model.

These specifications affect how the battery schedule should be designed.

During a period when the PV array is expected to provide sufficient energy, the system may use solar power for the load while directing available energy toward battery charging. When solar production decreases, a later period can be configured for battery discharge if required by the operating strategy.

However, predicted solar production is never completely fixed. Weather, shading, seasonal changes, and system conditions can all influence actual PV output. A schedule should therefore be based on realistic generation data rather than theoretical PV capacity alone.

Adapting the Schedule to Changing Loads

Time-based battery control can be particularly relevant for commercial and industrial facilities with predictable changes in electricity demand.

Imagine a production facility where the load is relatively low in the morning, increases during working hours, and remains active into the afternoon. A single charging or discharging period may not provide enough flexibility to reflect this pattern.

With six available windows, the battery strategy can be divided into more meaningful stages. One period may be used for charging when solar power is available, while later periods can make stored energy available during higher-demand operation.

Another period could be reserved for a different operating condition or battery-management requirement.

The purpose is not to use every available period simply because the inverter provides six. A better approach is to assign a time period only when there is a meaningful change in the site's energy conditions.

In this way, the scheduling function becomes part of system planning rather than just another specification on an inverter datasheet.

Battery Current and Capacity Still Matter

A schedule determines when charging or discharging is expected to occur, but it does not determine the electrical limits of the battery.

The JUNCESS models have different maximum charge and discharge currents:

Model	Maximum Charging Current	Maximum Discharging Current
JIL-12kW-EP-D	280 A	280 A
JIL-15kW-EP-D	330 A	330 A
JIL-20kW-EP-D	350 A	350 A

All three models support a 40–60 V battery voltage range and can work with lead-acid or lithium-ion batteries. For lithium-ion applications, the charging process can adapt according to available BMS information.

This means that a scheduled charging period does not mean the battery can charge at any arbitrary rate. Battery capacity, state of charge, permitted current, BMS limits, and manufacturer requirements still need to be respected.

For system design, scheduling and battery electrical parameters should therefore be evaluated together.

Scheduling Is Not the Same as Energy-Source Management

Another point worth understanding is that six time periods do not represent six separate energy sources.

Within the supported system architecture, the Three Phase Hybrid Inverter can integrate PV, battery, grid power, and a diesel generator. Energy from a diesel generator can also be stored in the battery according to the applicable configuration.

The time periods are primarily a method of organizing battery operation over the course of a day. They do not independently define which energy source must be used in each period.

For example, one charging window may be associated with available PV energy, while another operating window may involve another supported power source depending on the system configuration.

The priority between PV, battery, grid, and generator depends on the selected operating mode and installation design. This distinction is important because battery scheduling should complement the overall energy-flow strategy rather than replace it.

Three-Phase Loads and Unbalanced Output

Three-phase applications can introduce another consideration when designing battery operation.

The inverter supports 100% three-phase unbalanced output, with each phase capable of handling up to 50% of the rated power. This can be useful for sites where electrical loads are not evenly distributed among the three phases.

A battery schedule may specify when stored energy should be available, but the inverter still has to respond to the actual phase-by-phase demand.

The system can also support both on-grid and off-grid configurations. Up to 10 units can be connected in parallel according to the product specifications, while multiple batteries can also be connected in parallel.

For a larger installation, these capabilities provide options for increasing inverter and battery capacity as project requirements grow. The final configuration should always be matched to the expected load, battery architecture, and installation requirements.

A Practical Method for Creating the Schedule

Before setting six battery periods, it is useful to collect actual operating information from the site.

Start by identifying when the major loads operate and when electricity demand reaches its highest level. Then examine the PV generation profile to determine when solar power is normally available. Battery capacity and permitted charge/discharge current should also be checked.

Once these parameters are understood, the six periods can be assigned to actual operating conditions.

For example, a project might use an early window for charging, one or more daytime windows for PV and battery management, and later windows for afternoon or evening discharge.

If the system includes a generator or another supported energy source, its role should also be included in the overall energy-management plan.

There is no advantage in creating a complicated schedule when the site has only two or three meaningful operating conditions. More settings do not automatically produce better energy management.

The usefulness of six periods comes from being able to represent a genuinely variable daily load and generation pattern.

Monitoring and Communication

Battery scheduling becomes easier to manage when the inverter can communicate operating information to external devices or monitoring systems.

The JUNCESS inverter provides RS232, RS485, and CAN communication interfaces. Depending on the configuration, monitoring options can include GPRS, WiFi, Bluetooth, 4G, and LAN.

A local LCD and LED display can also provide operating information at the inverter.

For systems with multiple units or remote management requirements, communication functions can help operators review operating conditions and identify deviations from the expected schedule.

For example, if a battery does not charge during a scheduled window, the cause may not necessarily be the schedule itself. PV availability, battery state of charge, load demand, BMS information, or another operating parameter could affect the result.

Monitoring data can therefore be useful when checking actual performance against the planned battery strategy.

What to Check Before Configuring Battery Time Periods

Time-based control is only one part of the overall system design. Several basic parameters should be confirmed before creating the schedule.

Important items include:

• Battery voltage range

• Battery chemistry

• Battery capacity

• Maximum permitted charging current

• Maximum permitted discharging current

• PV capacity and expected production

• Daily and peak load demand

• Inverter operating mode

• Grid requirements

• BMS communication for lithium-ion batteries

• Installation environment

For lithium-ion systems, inverter and battery compatibility is particularly important because charging behavior can depend on information received from the BMS.

Environmental conditions should also be considered. The inverter is specified for operation from -40°C to +60°C, with derating above 45°C, and has an IP66 protection rating.

These specifications should be considered together with the actual installation environment when determining how the system will operate over extended periods.

Where This Type of Inverter May Fit

The combination of three-phase operation, multiple battery scheduling periods, PV input capability, and different energy-source options can be relevant to various solar-storage applications.

For example, a commercial facility may need to store excess solar energy during the daytime and make stored energy available later when electricity demand remains high. An industrial site may have a more complicated load profile requiring several battery operating windows.

Off-grid applications can also have different priorities because PV production, battery reserves, and generator availability may need to be coordinated.

In each case, the most suitable schedule depends on actual energy consumption and generation data rather than simply selecting a preset timetable.

About Jiangsu Juncess Energy Co., Ltd.

Jiangsu Juncess Energy Co., Ltd. has experience in the new energy sector covering areas such as R&D, manufacturing, distribution channels, and energy solutions.

The company has developed business relationships across Asia, Europe, Africa, the Middle East, and Australia, with more than 400 long-term strategic partners. Its energy-storage activities have developed alongside experience in photovoltaic and other new-energy technologies, with reported energy-storage production capacity of 1.5 GWh.

For projects evaluating the Three Phase Hybrid Inverter, the practical results of the six-period function depend on how closely the selected settings correspond to the site's actual generation, load, battery, and operating conditions.

Final Considerations

A battery schedule works best when it is built around real operating data.

The six charging and discharging periods available with the JUNCESS inverter provide a way to divide daily battery operation into several defined windows. Combined with PV input capacities of up to 24–32 kW for the listed models, maximum charge and discharge currents of up to 280–350 A, 40–60 V battery support, and multiple system configuration options, the inverter can be adapted to different energy-management requirements.

The key is not simply to create six schedules. Instead, each period should have a clear purpose based on PV generation, load demand, battery limits, and the selected system architecture.

For installers, system integrators, and energy-storage users, this approach can make time-based battery control a practical part of daily energy management rather than a feature used only at the configuration stage.

When the schedule is properly matched to actual operating conditions, the Three Phase Hybrid Inverter can provide a more structured way to coordinate battery charging and discharging throughout the day.

http://www.juncess.com
​Jiangsu Juncess Energy Co., Ltd.

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