PIKA B801 REcharge, Руководство по эксплуатации, Страница: 21 / 35

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7.5 Battery Voltage Limits
Battery systems often have multiple sources for battery charging such as a PV system and/or a
generator. It is important that all these systems are configured with the same battery voltage setpoints
so that each part of the system can perform the correct task at the correct time. The B801 is constantly
monitoring the battery bank voltage, if it is out of a safe range the B801 will take action to prevent
damage to the batteries. There are a variety of ways the B801 safely handles dangerous battery
voltages.
7.5.1 Low Battery Voltage
A user adjustable low battery voltage setpoint determines the “ Low Battery Voltage Threshold ” . For a
48V system the default Low battery voltage is 47V. For a 24V system the default Low Battery voltage is
23.5V.
The charge controller must draw a small amount of power to keep the REbus ™ DC microgrid at 34 0V so
that input devices such as the T701 Wind Turbine and the S2001 PV Link can still operate. During low
battery voltage state, if there isn’t any input power, the B801 will power -down the REbus ™ DC microgrid
to 0V in order to conserve power. The B801 enters a hibernation state and will wait a specified amount
of time before bringing the voltage on the REbus
™ DC microgrid back to 340V again. The “off” time and
“on” time for when the REbus ™ DC microgrid is at 0V or 34 0V are specified in the user setpoint table
(refer to Table 1 User Setpoint Table for more information about setpoints).
7.5.2 Error Low Battery Voltage
The state “ Error Low Battery Voltage ” occurs if the batteries are depleted to the point where they may
be damaged, rendering them unusable if they are discharged any further. Please check with the battery
manufacturer about extremely low voltage conditions for your battery bank size. For a 48V system
extremely low battery voltage is typically 45V. For a 24V system extremely low battery voltage is
typically 22.5V. A user adjustable setpoint determines the extremely low battery voltage threshold.
When the battery voltage is below this setpoint, the B801 will power down the REbus
™ DC microgrid to
conserve energy. The only way to bring the REbus ™ DC microgrid back up is to either manually
disable/re-enable the B801 from the LCD user interface screen or to power the B801 OFF then back ON
again with the power switch. After re-enabling, the B801 will power up the REbus one time, for the
amount of time specified by the “ Low Battery Time On ” setpoint, to create an opportunity for a REbus
source (e.g. wind turbine or solar panels) to start charging the batteries. If input power starts to charge
the batteries, the REbus
™ DC microgrid will stay powered up and continue to charge the batteries,
otherwise it will power down again and stay off until the user performs another disable/enable cycle.
Pika recommends that the user only ov
erride the “Error Low Battery V oltage ” state when there is input
power available from the sources (e.g. the wind is blowing or the sun is shining).
7.5.3 High Battery Voltage
In the event of a high battery voltage, the B801 will make an error and shutdown, user input is required
and the B801 will not automatically return to normal operation. High battery voltage is at 65V and is to
protect the circuitry of the B801 from being damaged. Note that the B801 will never charge a battery