Charged-Parameters - Studer SBM-01 Bedienungsanleitung

(1)
Please note that the rated battery capacity can also be defined as
the 10hr or even 5hr discharge rate.
(2)
The 5hr discharge rate in this example is just arbitrary. Make sure
that besides the C20 rating (low discharge current) you choose a
second rating with a substantially higher discharge current.
When no ratings are given at all, you can measure your battery using a
'constant load bank'. This way a second rating can be obtained, besides
the 20hr rating which represents the rated battery capacity in most
(1)
cases . This second rating can be defined by discharging a fully
charged battery with a constant current, until the battery reaches 1.75V
per cell (is 10.5V for a 12V battery or 21V for a 24V battery). a
calculation example is shown below :
A 200Ah battery is discharged with a constant current of 20A and after
8.5 hours 1.75V/cell is reached.
→ t1 = 8.5hr
So,
→ I1 = 20A
20hr rating, C20 = 200Ah
Peukert exponent n =
2.3

Charged-parameters

Based on increasing charge voltage and decreasing charge current, a
decision can be made whether the battery is fully charged or not. When
the battery voltage is above a certain level during a predefined time while
the charge current is below a certain level during the same time, the
battery can be considered as fully charged. These voltage and current
levels as well as the predefined time are called 'charged-parameters'. In
general for a 12V lead acid battery, the voltage-charged-parameter is
13.2V and the current-charged-parameter is 2.0% of the total battery
capacity (e.g. 4A with a 200Ah battery). A charged-parameter-time of 4
minutes is sufficient for most battery systems. Please note that these
→ t2 = 20hr
→ I2 = 200Ah/20hr = 10A
−
log 20 log 8 5 .
−
log 20 log 10
SBM-01 high precision battery monitor
= 1,23
7