Fields at Work GmbH, Sonneggstrasse 60, 8006 Zürich, Schweiz
2017 Fields at Work GmbH, Zurich
ExpoM - ELF manual rev. 1.1
Page 7/19
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4
Battery management
4.1
Charging the Battery
The USB interface is used to recharge the internal battery or power the device from an external
power source. Unless fully charged, the battery is recharged as soon as the device is connected to a
powered USB source (Wall adapter, PC, laptop etc.).
While ExpoM - ELF is charging the battery, the charging indicator LED near the USB connector lights
solid red. At the end of the charging cycle the red indicator LED turns off.
Important Notice:
Using USB chargers that do not fulfill the USB dedicated charger port specification
can lead to incomplete and slow charging process of the batteries.
It is strongly recommended to
use an USB charger with a current rating of at least 1A (1000mA)
. More information about suitable
USB charger types for ExpoM - ELF can be obtained from the distributor.
Important Notice:
At environmental temperatures above 45°C ExpoM - ELF should not be charged.
Direct exposure to sunlight during the charging process should be avoided.
Note:
The actual charging time depends on the charger model and the type of USB cable used. Long
and / or thin USB cables can significantly increase the required charging time regardless of which
type of charger is used. It is recommended to use the USB cable provided with the device.
4.2
Over-Discharge Protection (Automatic Shutdown)
To preserve its capacity over time, the internal battery must be prevented from being discharged
below a critical level. ExpoM - ELF includes a battery monitoring circuit that powers the device down
when a critically low battery level is detected. After such an automatic power down it is
recommended to put the ON/OFF switch in the OFF position and charge the device for at least 10
minutes before switching it on again.
