19
Temperature effects
Ambient temperatures have a large influence on battery capacity. At low temperatures, the capacity drops
quickly. This is illustrated in figure 24 (capacity of a gel battery). The temperature of the room where the
batteries are installed must therefore be kept above 10 °C.
Maximising battery service life
Batteries must not be left in the discharged state for too long, because doing so reduces their service life. With
this in mind, various protection mechanisms have been built into the PowerRouter.
Maintenance charging
At regular intervals – once every 3 weeks – the battery
is forced to run through the 3-state charging cycle.
If maintenance charging coincides with a request for
self-generated power, charging will take priority. Once
the battery is fully charged and the SOC is 100%,
maintenance charging is complete and the battery
becomes available for self-use again.
Likewise, in the winter mode, this cycle of maintenance
continues. The battery module is activated and the
battery charged to 100%, after which the winter mode
is once again activated.
It is possible to start or stop the maintenance charging
manually in the PowerRouter’s display menu. However,
to achieve the maximum service life from the battery,
this is not recommended.
Winter mode
This mode is for using the batteries in the winter, when
there is less solar output and greater demand. This
annual cycle is shown in figure 25, as the blue line
which represents total household consumption.
Because solar output only now and again exceeds
consumption, full charging of the battery occurs less
frequently. Longer periods without full charging shorten
the service life of the battery. This is the reason for the
winter mode, as this protects the battery and ensures a
longer service life.
The moment the system is switched to winter mode, maintenance charging begins, to fully charge the battery.
Once at maximum charge, the PowerRouter’s battery module is switched off. There is no more self-use from
the battery. The period during which the battery is in the winter mode can be programmed with the installation
tool. The standard period is from 1 December to 1 February. At the end of this period, the system completely
recharges the battery again and it can be used for self-use. It is important to choose this period carefully, taking
into account whether or not the system is equipped with a 3-phase sensor. If it is, consumption will be higher
than for a 1-phase measurement.
Figure 24: Temperature versus battery capacity
Figure 25: Winter mode
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Wintermodus
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