SMA SI 3324 - Manual (Page 36)

Battery Management SMA Technologie AG
Page 36 SI3324/4248-14:FE2406 User Manual
6.1 Charge Control
The Sunny Island 3324/4248 has a 3-level charge control using the IV
0
V process.
The I stands for the bulk phase. At this level, the charging is only limited by the
defined maximum battery current ("23-4 AmpdcBatMax" parameter) or by the
maximum generator current ("24-2 AmpacGenMax" parameter). During this phase
the battery voltage increases as the batteries are charged.
Once the battery voltage has reached the value defined for the second phase V
0
,
then the constant voltage charging (absorption phase) begins. At this level, the
battery voltage is maintained at a constant level, resulting in a continually decreasing
battery current. The Sunny Island 3324/4248 remains in this phase for the period of
time defined for this phase (parameters "12-6 TabsorbLeft").
Once this phase is finished, the Sunny Island 3324/4248 enters the float charge that
again provides constant current charging but at a greatly reduced charging voltage.
If charging is done from a generator, then this is stopped on entry to this phase, thus
ending charging of the batteries at this point. The Sunny Island 3324/4248 remains
in this phase until either more than 30 % of the nominal capacity has been used (all
discharges are summed) or the generator is automatically restarted (see section 5.2
"Generator Parameters" (page 29)).