Omega OM-CP-RF Series, User Manual

Page: 17 / 22

OM-CP-RF Series Operations Manual
Omega Engineering, Inc. Revised 04/07/05 Page 15 of 18
BATTERY LIFE
There are many variables that affect the battery lifetime. These variables include (but
are not limited to) sample rate, transmit rate, LED settings, transmission settings, ambient
temperature and battery self-discharge.
For the purposes of approximating battery life, please consult Tables 3 and 4 below.
These numbers should not be used as an absolute guarantee, but as an approximate guide
for deciding when the battery will need replacement. This table is useful because the lithium
batteries used in the OM-CP-RF products do not show a strong correlation between voltage
and remaining capacity, which makes it very difficult to measure their remaining life. In
lithium batteries, the voltage stays very nearly constant for the entire life of the battery
until it drops sharply and suddenly when depleted.
There are variables that it is not possible to account for in the tables. The table assumes
a pattern of continuous use, in which both the logger and transmitter features are used such
that both the transmitter and logger are active at approximately the indicated “activity rate”
(for cases where the logger and transmitter operate at different rates, use the faster rate
for estimation). The calculations assume that the device is configured and deployed, then
downloaded and redeployed when the logger is nearly full.
Table 3. Estimated battery life
ACTIVITY RATE
WORST CASE FACTORY DEFAULT BEST CASE
30 seconds 3 months 6 months 6 months
1 minute 6 months 12 months 12 months
2 minutes 12 months 20 months 24 months
3 minutes 15 months 27 months 3 years
4 minutes 21 months 33 months 3.5 years
5 minutes 24 months 3 years 4 years
6 minutes 27 months 3.5 years 5 years
8 minutes 33 months 4 years 6 years
10 minutes 3 years 4.5 years 7 years
15 minutes 4 years 5 years 8.5 years
30 minutes 5 years 6 years 10+ years
1 hour 6 years 6.5 years 10+ years
2 hours 6.5 years 7 years 10+ years
4 hours 7 years 7+ years 10+ years
The transmitter settings used to calculate the best, worst and factory default cases are
indicated in Table 4.
Table 4. Transmitter settings for battery life estimation
WORST CASE FACTORY DEFAULT BEST CASE
Wireless Output Enabled Enabled Enabled
Serial Output Not Significant Not Significant Not Significant
Logging Option Not Significant Not Significant Not Significant
Switch Option Not Significant Not Significant Not Significant
Randomization Enabled Disabled Disabled
Error Correction Enabled Disabled Enabled