MT MPP170, MT MPP260, MT MPP 440
Installing the MPP solar charger
EN
19
3: U2 phase (Trickle charging)
The U2 phase serves to maintain the battery capacity (100 %).The U2 phase runs at lowered
charging voltage and variable current. If DC loads are connected, they are powered by the device.
Only if the power required exceeds the capacity of the device, this surplus power is provided by
the battery. The battery then is discharged until the device re-enters the I phase and charges the
battery.The U2 phase is limited to between 24 and 48 h depending on the battery type.
6.4
Temperature sensor
With the temperature sensor connected, the MPP solar charger adjusts the charging voltage (for
lead batteries) or the charging current (for lithium batteries) according to the measured tempera-
ture at the battery.
I
The charging characteristics are adjusted as follows:
• For lead acid batteries see fig.
• For lead gel batteries see fig.
• For AGM batteries see fig.
• For LiFePO4 batteries (13.9 V) see fig.
• For LiFePO4 batteries (14.2 V) see fig.
• For LiFePO4 batteries (14.4 V) see fig.
• For LiFePO4 batteries (14.7 V) see fig.
Legend
7
Installing the MPP solar charger
NOTE
Without the temperature sensor connected or if the temperature sensor is defective,
the charging voltage is referenced to 20 °C.
Charging curve without temperature sensor connected
Charging curve with temperature sensor connected
The electrical power supply must be connected by a qualified electrician who has
demonstrated skill and knowledge related to the construction and operation of
electrical equipment and installations, and who is familiar with the applicable
regulations of the country in which the equipment is to be installed and/or used,
and has received safety training to identify and avoid the hazards involved.
