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3.7 Battery charging information
The charge controller starts a new charge cy cle ev ery moring,
when the sun starts shining.
The maximum duration of the absorption period is determined by
the battery v oltage measured just bef ore the solar charger starts
up in the morning:
Battery v oltage Vb (@start-up)
Maximum absorption time
Vb < 23,8V
6 h
23,8V < Vb < 24,4V
4 h
24,4V < Vb < 25,2V
2 h
Vb > 25,2V
1 h
(div ide v oltages by 2 f or a 12 V sy stem and multiply by two in
case of a 48V sy stem)
If the absorption period is interrupted due to a cloud or due to a
power hungry load, the absorption process will resume when
absorption v oltage is reached again later on the day , until the
absorption period has been completed.
The absorption period also ends when the output current of the
solar charger drops to less than 2 Amps, not because of low solar
array output but because the battery is f ully charged (tail current
cut of f ).
This algorithm prev ents ov er charge of the battery due to daily
absorption charging when the sy stem operates without load or
with a small load.
