AMETEK SLM Series RevC - Manual (Page 55)

Sorensen SLM-Series DC Load Applications
M540071-01 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 SLM-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 SLM-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 SLM-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, SLM-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
Ao
W
T
(c) The output power of battery
Wo
Battery
Plow Phigh
(e) Constant Power Mode (DYNAMIC)
Battery
(d) Constant Power Mode (STATIC)
Figure 4-7 Constant Power Mode Application