ICS1700A Datasheet, PDF (3/24 Pages) List of Unclassifed Manufacturers – QuickSaver Charge Controller for Nickel-Cadmium and Nickel-Metal Hydride Batteries

ICS1700A
Controller Operation
Charging Stages
The charging sequence consists of four stages. The application of
current is shown graphically in Figure 1. The soft start stage
gradually increases current levels up to the user selected fast
charge rate during the first two minutes. The soft start stage is
followed by the fast charge stage, which continues until
termination. After termination, a two hour C/10 topping charge is
applied. The topping charge is followed by a C/40 maintenance
charge.
Soft Start Charge
Some batteries may exhibit an unusual high impedance condition
while accepting the initial charging current, as shown in Figure 2.
Unless dealt with, this high impedance condition can cause a
voltage peak at the beginning of the charge cycle that would be
misinterpreted as a fully charged battery by the voltage termination
methods.
The soft start charge eases batteries into the fast charge stage
by gradually increasing the current to the selected fast charge rate.
The gradual increase in current alleviates the voltage peak. During
this stage, only positive current pulses are applied to the battery.
The duty cycle of the applied current is increased to the selected
fast charge rate, as shown in Figure 3, by extending the current
pulse on every cycle until the pulse is about one second in duration.
The initial current pulse is approximately 200ms. The CMN
indicator is activated continuously during this stage
Average
Current
(not to scale)
Soft-Start Fast Charge
Topping Charge
Maintenance Charge
Stage 1
Stage 2
0
2 min
termination
Stage 3
Stage 4
termination + 2 hours Time (not to scale)
Figure 1: Graphical representation of average current levels during the four charging stages
Figure 2: High impedance voltage spike at the beginning of charge
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