KOSTAL Pressebereich


The KOSTAL battery sleep mode rethought

KOSTAL has a special sleep mode in the PLENTICORE inverter series which puts the connected battery storage unit into a special sleep mode during periods of low solar radiation.

Even if the sun rarely appears in the cold seasons, it is by no means necessary to deactivate the storage unit to avoid deep discharge. A special battery rest mode of the PLENTICORE hybrid and battery inverters from KOSTAL ensures that the battery does not fall below a charge level specified by the battery manufacturer.

The PLENTICORE's rest mode reacts in a battery-friendly, automated manner and has now been rethought.

Andreas Schmalenberg, Senior Product Manager for the PLENTICORE inverter series, explains the new configuration for the battery rest mode: "Originally, the PLENTICORE had a two-stage system that, in the absence of PV energy supply, checked for 48 hours whether the storage unit could return from rest to normal operation and be used.
We have now significantly improved this process and made it more efficient, so that a connected battery storage system is also available for longer in winter months. At the same time, the battery storage immediately switches to sleep mode if the state of charge falls below the value specified by the battery manufacturer."

PLENTICORE inverter with battery sleep mode

The PLENTICORE inverter offers the possibility for a storage connection via a specially unlockable bidirectional DC input. With intelligent battery control, regenerative energy is thus optimally made available for later self-consumption. Under the control of the inverter and a KOSTAL Energy Meter, the connected battery storage unit feeds the stored PV energy into the house consumption.

The PLENTICORE is therefore able to direct the battery depending on its status. Deep discharge protection ensures that the battery is automatically recharged with an emergency charge from mains power or connected AC sources.

How does the battery rest mode work?

First, the battery storage is discharged to a minimum percentage specified by the manufacturer. This may occur during the entire year in the case of large domestic consumption. In this case, the battery storage is put directly into sleep mode and disconnected from the system to protect against deep discharge. As soon as the battery can be charged again with surplus energy, the sleep mode is automatically terminated and the storage unit is returned to normal operation.

"Sleep mode is exited as soon as the storage unit can be charged with surplus energy again," explains Andreas Schmalenberg. "The storage can then be fully used immediately. The two-day wake-up phases are thus a thing of the past."

Once the sleep mode has been exited, it is reset and starts again at 5 per cent the next time it is used. The current state of charge of the battery can be easily viewed via the battery menu via web server.

"Unfortunately, storage systems have the effect of self-discharge, for example due to the integrated management system of the battery," adds Andreas Schmalenberg. "This can cause the state of charge to fall below the minimum value specified by the manufacturer. In this case, the PLENTICORE initiates a so-called trickle charge."

This trickle charge for the battery is staggered according to a certain principle. When the battery falls below the minimum discharge depth for the first time, the trickle charge recharges by five percent, when it falls below the minimum discharge depth for the second time by ten percent, and when it falls below the minimum discharge depth for the third time by 15 percent. In low-yield periods such as winter, this mechanism prevents frequent recharging from the grid.

"We work closely with our storage partners so that the PLENTICORE harmonises perfectly with the manufacturer's conditions. The charging range specified by the manufacturer is thus precisely taken into account by the KOSTAL inverter. The idle mode works the same for all released battery storage units in the same way. It couldn't be simpler for the user," Andreas Schmalenberg concludes.

With the new configuration of the battery sleep mode, KOSTAL remains true to its line: designing products flexibly and efficiently. With the way the device feature works, not an hour of sunlight is wasted. Thus, even in times of low solar irradiation, optimal PV yields are achieved for higher electricity self-sufficiency and greater self-consumption.