AMETEK SLH Series RevC - Manual (Page 61)

Sorensen SLH-Series DC High Power Electronic Load Applications
M540074-01 Rev C 4-7
4.6 CONSTANT POWER (CP) MODE APPLICATION
Major Application: Test and evaluate a battery's energy capacity.
Primary or secondary battery is the power source for every portable electronics product, such
as notebook computer, video camera, etc. A typical sequence of battery output is where the
output voltage of battery begins to drop (Figure 4-7a) according to the output current and usage
duration. (Figure 4-7b); however, it should provide a stable power output regardless of output
voltage (Figure 4-7c), therefore, the energy capacity (output power x time) is one of the most
important factors in evaluating a battery.
In CP mode, the SLH-series DC electronic load can sink constant power load for a battery; the
load current increases as the battery’s output voltage drops; the load power will remain equal to
the load power setting of CP mode (Figure 4-7d), the SLH-series DC electronic load in CP
mode with time record can be used to evaluate the energy capacity or discharge life time of a
battery.
Moreover, the real power could be a dynamic loading condition. The SLH-series DC CP mode
can be operated in Dynamic power load as well, setting the STA/DYN to DYN on the front panel
or remote programming, SLH-series DC load can sink dynamic power waveform to test the
dynamic characteristics of battery (Figure 4-7e).
V
T
(a) The output voltage of battery
Vo
A
T
(b) The output current of battery
W
T
(c) The output power of battery
Ao Wo
Battery Battery
Plow Phigh
(e) Constant Power Mode (DYNAMIC)
(d) Constant Power Mode (STATIC)
Figure 4-7 Constant Power Mode Application