Users Manual Chapter 1

Thor VM3A Vehicle-Mounted Computer 5
External AC Power Supply
If DC power is not available, for example, in an office environment, an optional
external Universal Input Power Supply can be used to convert AC wall outlet to an
appropriate DC level. AC to DC power input for the computer is delivered to the
dock via an optional external power supply and adapter cable. See External AC/DC
Power Supply. The external power supply should be used with the VMXD Dock.
Uninterruptible Power Supply
• The VM3A contains an internal UPS battery backup. The user can Replace the
UPS Battery.
• The UPS battery is automatically charged when the computer is placed in a
powered dock, provided the Safe Charging Temperature Range is met.
• When external power is removed, the UPS automatically powers the computer
with no user intervention. When running on UPS power, the power management
timeouts may be different than when vehicle power is applied.
• The UPS allows the computer to continue operation when not mounted in a dock
or when the vehicle battery is being swapped. When fully charged, the UPS
battery is designed to power the computer for a minimum of 15 minutes at
temperatures of 20ºC (68ºF) or greater.
• If operating on UPS power and the UPS battery becomes critically low, the
computer performs a controlled shutdown.
• If there is no external power available, there must be 10% or greater power in the
UPS battery or the computer does not power On.
• The UPS status LED and the Battery Control Panel can be used to monitor the
status of the UPS battery.
Safe Charging Temperature Range
The internal temperature of the VM3A is the trigger for UPS battery charging.
• The UPS battery is not charged when the internal temperature is below 0°C
(32°F). This corresponds to an ambient (room) temperature of approximately
-10°C (-14°F).
• The UPS battery is not charged when the internal temperature is above 40°C
(104°F). This corresponds to an ambient (room) temperature of approximately
35°C (95°F).
• If the UPS battery cannot be charged due to a temperature extreme, the UPS
Status LED is amber. Move the VM3A to a different location to charge the UPS
battery.
Caution: Safety requirements restrict the temperature at which the Li-Ion UPS
battery can be charged. Charging is disabled if the temperature is
outside of the 0° to 35°C safe charging range. In order to maintain
UPS charge, the Thor VM3A should have power applied while the unit
is within the safe charging range for at least an hour each day.