Battery Results

run /usr/bin/olpc-logbat to record battery usage, and the results are logged under /root

7/13/2007

This test used the first 20 XOs set up in group A. The test was intended to compare the effectiveness of the lithium batteries vs. the nickel metal hydride batteries, as well as the effect of having the backlight on or off. We used the program Logbat, which returns the battery's current charge every 20 seconds, to determine the lifespan of the battery. Once Logbat was running on all 20 XOs, we unplugged all the power cords and left the XOs alone overnight. The nickel metal hydride batteries were found to have major problems - most of them died within half an hour of the XOs being unplugged, and the few that lasted longer than that still had a shorter duration than most of the lithium batteries.

 Name,SN,Type,SKU,Duration,Brightness,Build
 A01,SHF7250021A,Ni,B4-16,, 4 hr 9 min, off,502 
 A02,SHF725004BA,Ni,B4-14,, 9.6 min,    off,502 *
 A03,SHF725004BC,Li,B4-14,, 5 hr 24 min,off,502
 A04,SHF725004B7,Li,B4-14,, 5 hr 9 min, off,502
 A05,SHF7250016D,Li,B4-13,, 5 hr 10 min,off,502
 A06,SHF72500190,Li,B4-13,, 4 hr 50 min,off,502
 A07,SHF725004CC,Ni,B4-14,, 16.8 min,   off,502 *
 A08,SHF72500200,Ni,B4-16,, 8.4 min,    off,502 *
 A09,SHF725001BA,Ni,B4-13,, 10.2 min,   off,502 *
 A10,SHF72500173,Li,B4-13,, 5 hr 15 min,off,502
 A11,SHF725001D0,Li,B4-13,, n/a,        full,502
 A12,SHF72500193,Li,B4-13,, 4 hr 52 min,full,502
 A13,SHF725001CB,Li,B4-13,, 4 hr 9 min, full,502
 A14,SHF72500244,Li,B4-16,, 4 hr 45 min,full,502
 A15,SHF72500208,Li,B4-16,, 5 hr 9 min, full,502
 A16,SHF7250022A,Ni,B4-16,, 2 hr 41 min,full,502 *
 A17,SHF725004B5,Ni,B4-14,, 21 min,     full,502 *
 A18,SHF725004BD,Ni,B4-14,, n/a,        full,502
 A19,SHF725004C3,Ni,B4-14,, 10.2 min,   full,502 *
 A20,SHF725004C8,Ni,B4-14,, 13.8 min,   full,502 *

7/16/2007

This test also used the first 20 XOs set up in set A and followed the same basic format as the test from 7/13, except that the first 10 XOs had their backlight turned off for this test rather than the last 20. Again, the nickel metal hydride batteries experienced had shorter lifespans, though far fewer of them died within minutes this time around. When functioning properly, the nickel batteries seemed to last about an hour shorter than the lithium batteries.

 Name,Serial Number,Battery,SKU,Duration,Brightness,Build
 A01,SHF7250021A,Ni,B4-16,, 4.2 min,    full,502 *
 A02,SHF725004BA,Ni,B4-14,, 4 hr 7 min, full,502
 A03,SHF725004BC,Li,B4-14,, 5 hr 15 min,full,502
 A04,SHF725004B7,Li,B4-14,, 5 hr 1 min, full,502
 A05,SHF7250016D,Li,B4-13,, 5 hr 1 min, full,502
 A06,SHF72500190,Li,B4-13,, 4 hr 32 min,full,502
 A07,SHF725004CC,Ni,B4-14,, 4 hr 4 min, full,502
 A08,SHF72500200,Ni,B4-16,, 2.4 min,    full,502 *
 A09,SHF725001BA,Ni,B4-13,, 3 hr 45 min,full,502
 A10,SHF72500173,Li,B4-13,, 5 hr 7 min, full,502
 A11,SHF725001D0,Li,B4-13,, 5 hr 4 min,  off,502
 A12,SHF72500193,Li,B4-13,, 4 hr 58 min, off,502
 A13,SHF725001CB,Li,B4-13,, 4 hr 32 min, off,502
 A14,SHF72500244,Li,B4-16,, 5 hr 10 min, off,502
 A15,SHF72500208,Li,B4-16,, 5 hr 11 min, off,502
 A16,SHF7250022A,Ni,B4-16,, 4.8 min,     off,502 *
 A17,SHF725004B5,Ni,B4-14,, 4 hr 15 min, off,502
 A18,SHF725004BD,Ni,B4-14,, n/a,         off,502
 A19,SHF725004C3,Ni,B4-14,, 4 hr 9 min,  off,502
 A20,SHF725004C8,Ni,B4-14,,4 hr 5 min,   off,502

7/17/2007

This test also used the first 20 XOs in set A and followed the same format as the first test, with one exception - A11-15 had their BYD lithium batteries replaced with Gold Peak lithium batteries. In this test, none of the nickel metal hydride batteries had an extremely short lifespan as was the case in the first two. However, average performance among both lithium and nickel metal hydride batteries was down significantly. This was due in part to several of the lithium batteries being changed to Gold Peak lithium batteries which, apparently, have considerably lower battery life than the BYD lithium batteries.

Name,Serial Number,Battery,SKU,Duration,Brightness,DCON,Build
A01,SHF7250021A,Ni,B4-16,, 4 hr 13 min,  off,no,502
A02,SHF725004BA,Ni,B4-14,, 3 hr 56 min,  off,no,502
A03,SHF725004BC,Li,B4-14,, 5 hr 23 min,  off,no,502
A04,SHF725004B7,Li,B4-14,, 5 hr 9 min,   off,no,502
A05,SHF7250016D,Li,B4-13,, 5 hr 9 min,   off,no,502
A06,SHF72500190,Li,B4-13,, 4 hr 48 min,  off,no,502
A07,SHF725004CC,Ni,B4-14,, 4 hr 16 min,  off,no,502
A08,SHF72500200,Ni,B4-16,, 3 hr 50 min,  off,no,502
A09,SHF725001BA,Ni,B4-13,, 3 hr 55 min,  off,no,502
A10,SHF72500173,Li,B4-13,, 5 hr 15 min,  off,no,502
A11,SHF725001D0,Li,B4-13,, 4 hr 13 min, full,no,502
A12,SHF72500193,Li,B4-13,, 4 hr 20 min, full,no,502
A13,SHF725001CB,Li,B4-13,, 3 hr 47 min, full,no,502
A14,SHF72500244,Li,B4-16,, 3 hr 56 min, full,no,502
A15,SHF72500208,Li,B4-16,, 3 hr 53 min, full,no,502
A16,SHF7250022A,Ni,B4-16,, 3 hr,        full,no,502
A17,SHF725004B5,Ni,B4-14,, 3 hr 6 min,  full,no,502
A18,SHF725004BD,Ni,B4-14,, 2 hr 25 min, full,no,502 *
A19,SHF725004C3,Ni,B4-14,, 3 hr 4 min,  full,no,502
A20,SHF725004C8,Ni,B4-14,, 3 hr 5 min,  full,no,502

7/18/2007

This test was originally intended to be more extensive, including 45 XOs between set A and set B, and testing the effects of DCON mode. However, due to an error in the test procedure not all of this data was abled to be gathered. We used the test as an opportunity to gather more data bout the nickel metal hydride batteries, using XOs 16 to 25 from the A set. Again, the NMH batteries displayed both general lower performance when compared to lithium, as well as several extremely short durations.

Name,Serial Number,Battery,SKU,,Duration,Brightness,DCON,Build
A16,SHF7250022A,Ni,B4-16,, 3 hr 57 min,full,no,515
A17,SHF725004B5,Ni,B4-14,, 4 hr 15 min,full,no,515
A18,SHF725004BD,Ni,B4-14,, 3 hr 59 min,full,no,515
A19,ShiF725004C3,Ni,B4-14,, 4 hr 36 min,full,no,515
A20,SHF725004C8,Ni,B4-14,, 3 hr 58 min,full,no,515
A21,SHF725004F0,Ni,B4-15,, 1 hr 10 min, off,no,515 *
A22,SHF725004E8,Ni,B4-15,, 18.6 min,    off,no,515 *
A23,SHF7250051C,Ni,B4-15,, 18 min,      off,no,515 *
A24,SHF725005F9,Ni,B4-15,, 23.4 min,    off,no,515 *
A25,SHF7250050D,Ni,B4-15,, 2 hr 50 min, off,no,515

7/19/2007

This test used was of both a larger scope and a different model than the previous tests. 45 XOs between sets A and B were used. A1-15 were left idle after using the command "xset dpms force off" which immediately turned off the screen's display and backlight. A16-A20 and B1-B10 were left idle after using the command "xset -dpms," which forces the screen's display to stay on even after 10 minutes of idling. A21-25 and B11-B20 were left idle after using the command "xset -dpms" and turning the backlight off. The test was designed to compare the difference in battery life with the screen's display and/or backlight on or off.

We found that, with both the display and backlight on, the battery life was shortened significantly (by 1-1/2 to 2 hours on average). With the display on and the backlight off, the hit was far less significant (about 1/2 hour).

Name,Serial Number,Battery,SKU,,Display,Brightness,Build,Duration
A01,SHF7250021A,Ni,B4-16,,off,off,515,4.8 min * 
A02,SHF725004BA,Ni,B4-14,,off,off,515,4 hr 7 min
A03,SHF725004BC,Li,B4-14,,off,off,515,5 hr 21 min
A04,SHF725004B7,Li,B4-14,,off,off,515,5 hr 4 min
A05,SHF7250016D,Li,B4-13,,off,off,515,4 hr 56 min
A06,SHF72500190,Li,B4-13,,off,off,515,4 hr 45 min
A07,SHF725004CC,Ni,B4-14,,off,off,515,4 hr 3 min
A08,SHF72500200,Ni,B4-16,,off,off,515,4.2 min *
A09,SHF725001BA,Ni,B4-13,,off,off,515,3.6 min *
A10,SHF72500173,Li,B4-13,,off,off,515,5 hr 6 min
A11,SHF725001D0,Li-GP,B4-13,,off,off,515,4 hr 15 min
A12,SHF72500193,Li-GP,B4-13,,off,off,515,4 hr 22 min
A13,SHF725001CB,Li-GP,B4-13,,off,off,515,4 hr
A14,SHF72500244,Li-GP,B4-16,,off,off,515,4 hr 8 min
A15,SHF72500208,Li-GP,B4-16,,off,off,515,4 hr 17 min
C01,SHF725004EA,Ni,B4-15,,on,on,515,n/a
C02,SHF725004E5,Ni,B4-15,,on,on,515,2 hr 3 min 
C03,SHF725004F1,Ni,B4-15,,on,on,515,9 min *
C04,SHF725004E7,Ni,B4-15,,on,on,515,15 min
C05,SHF725004F5,Ni,B4-15,,on,on,515,18.6 min *
C06,SHF72500184,Li,B4-15,,on,on,515,3 hr 22 min
C07,SHF72500198,Li,B4-13,,on,on,515,3 hr 31 min
C08,SHF725001B6,Li,B4-13,,on,on,515,3 hr 25 min
C09,SHF725001C1,Li,B4-13,,on,on,515,n/a
C10,SHF72500186,Li,B4-13,,on,on,515,3 hr 17 min
D01,SHF725004F7,Ni,B4-15,,on,on,515,27 min *
D02,SHF72500546,Ni,B4-15,,on,on,515,2 hr 15 min 
D03,SHF72500544,Ni,B4-15,,on,on,515,2 hr 14 min 
D04,SHF72500541,Ni,B4-15,,on,on,515,1 hr 53 min 
D05,SHF72500537,Ni,B4-15,,on,on,515,2 hr 26 min 
D06,SHF7250019A,Li,B4-13,,on,off,515,4 hr 29 min
D07,SHF72500194,Li,B4-13,,on,off,515,4 hr 33 min
D08,SHF7250018D,Li,B4-13,,on,off,515,4 hr 35 min
D09,SHF725001B1,Li,B4-13,,on,off,515,4 hr 30 min
D10,SHF72500171,Li,B4-13,,on,off,515,4 hr 17 min
D11,SHF7250047E,Ni,B4-14,,on,off,515,2 hr 59 min
D12,SHF72500470,Ni,B4-14,,on,off,515,2 hr 5 9 min
D13,SHF725004C0,Ni,B4-14,,on,off,515,n/a
D14,SHF72500478,Ni,B4-14,,on,off,515,2 hr 51 min
D15,SHF72500486,Ni,B4-14,,on,off,515,2 hr 56 min
D16,SHF72500240,Li,B4-16,,on,off,515,4 hr 13 min
D17,SHF7250023C,Li,B4-16,,on,off,515,4 hr 47 min
D18,SHF7250023E,Li,B4-16,,on,off,515,4 hr 19 min
D19,SHF725001DE,Li,B4-16,,on,off,515,4 hr 56 min
D20,SHF72500255,Li,B4-16,,on,off,515,4 hr 40 min