I charged up the Epson HX-20 that I bought on Sunday, and it doesn't
seem to like me. The screen flickers out after a minute or so of use.
This seems to indicate a bad battery, but this hypothesis does not
appear to be borne out by lab tests.
Therefore, a lab report:
PURPOSE:
To determine if the battery pack from subject computer is
defective.
APPARATUS:
Battery pack in question (4xsubC, 4.8V)
Fluke 73-III handheld multimeter
Hewlett-Packard 6060B DC electronic load
Miscellaneous cables
47-ohm and 100-ohm resistors
PROCEDURE:
1. Measure open-circuit voltage of battery. Reading is 5.16
VDC.
2. Wire battery directly to load. Power on. Display reads
5.14 VDC, 0.03 A. Load is set as follows:
Range 6.0000 A
Input Off (htf do you turn it on?)
Short On (same)
Tran Off
Freq 1000
Slew .50000
Duty cycle 50.0
Mode Current
3. Dial in current at assorted amperages. Results:
Current Actual
requested (A) current (A) Voltage (VDC)
0.000 0.03 5.14
0.100 0.11 5.09
0.150 0.16 5.08
0.200 0.21 5.06
0.250 0.26 5.04
0.500 0.52 4.98
1.000 1.00 4.98
0.000 0.01 5.09
4. Try some resistance values.
Resistance (O) Current (A) Voltage (VDC)
5000 -0.01 5.11
1000 -0.01 5.11
500 -0.01 5.11
100 0.03 5.11
50 0.08 5.09
25 0.18 5.04
10 0.48 4.98
5 0.97 4.89
5. Connect a resistor across the battery terminals, and measure
the current.
Resistor: 100 ohms (spec)
102.3 ohms (measured)
Current: 47.3 mA
Resistor: 47 ohms (spec)
46.3 ohms (measured)
Current: 98.0 mA
CONCLUSION:
This battery pack doesn't look too defective, although I really
don't know too much about what the characteristics of a
functioning pack are.
Could someone who knows these things tell me if this pack is indeed
okay, as these tests seem to indicate, or if it is indeed bad?
--
Brad Ackerman N1MNB "...faced with the men and women who bring home
bsa3_at_cornell.edu the pork, voters almost always re-elect them."
http://skaro.pair.com/ -- _The Economist_, 31 Oct 1998
Received on Wed Jun 23 1999 - 16:48:12 BST