The following information was obtained from the manufacturer's website, Juniper
Systems
The rugged handheld computer always turns on immediately when a proper external power source is attached. If you briefly
press the Power button to Suspend the unit while external power is already attached, it may still Resume (turn back on)
automatically after a few seconds. This is an occasional side-effect of the "Rapid Charge Mode".
Attaching the rugged handheld computer (through the bottom DC Jack) to a vehicle charger (cigarette lighter adapter)
or other direct 12-24V power source that has a high or no current limit could allow the "rapid charge" feature of the
handheld to source up to 36 watts (3 amps @ 12V). At such a rate, this can charge two-thirds of the battery capacity
within one hour, providing many more hours of operation.
The handheld will slowly increase current draw from the external power source until it reaches the maximum available (or
its own limit) for charging the inserted battery as described at the above linked web page. Though occasionally this can
cause the external power source (such as wall charger) to reset, making it appear as if the external power source had
been detached (unplugged) then re-attached. This then again prompts the rugged handheld computer to automatically Resume
from Suspend (wake up). This usually only occurs for the first few minutes while charging, and leaving the unit on while
charging should not significantly affect charge time (particularly when charging over every night and weekend as
recommended).
If you would like the unit to automatically Suspend ("turn off screen") even while on external power, check the box
and set the timer under Start > Settings > System > Power > Advanced tab.