Understanding Battery Operations
Do not touch the patient and the circuitry in the battery compartments of the MR400
Cart batteries, when installed (main) and switched on (reserve), are charged and conditioned by
an integrated charging system. When turned on and connected to AC mains, the MR400 operates
from AC power and simultaneously charges all cart batteries. When turned off and connected to
AC mains, battery charging functions continue.
If at any time, AC mains is lost, the MR400 will automatically switch to battery power to provide
uninterrupted service—then, when AC mains is restored, the MR400 will automatically, without
delay, revert back to AC power functions. If the reserve batteries are fully depleted and AC mains
is lost, then the unit will power off.
The MR400's maximum operating time on battery power depends upon the enabled parameters
and the type and frequency of monitoring functions (see the Battery, Operation Time on page A‐4
for a listing).
Charging Cart Batteries
Cart batteries must be charged before initial use. During initial setup or when installing new
batteries, charge the cart batteries for at least 12 hours so that they are fully charged and
conditioned for operation.
Expression MR400 Instructions for Use Important Information 1‐21
Use only with the specified battery charger.
The main batteries must always be inserted and the reserve batteries must always be
switched on to prevent loss of patient monitoring during a power outage. If main batteries
are not inserted and if the reserve batteries are not switched on, then during power outage
unsaved user settings will revert to factory defaults.
We recommend plugging the MR400 into a backup generator or equivalent means to
prevent a lapse in patient monitoring during a power loss.