Diamond Aircraft DA 40 NG, Airplane Flight Manual

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Airplane
Description
DA 40 NG AFM
Page 7 - 40 Rev. 3 01-Jul-2014 Doc. # 6.01.15-E
Storage
Main battery power is stored in a 24 V, 13.6 Ah lead-acid battery mounted behind the
baggage compartment frame. The main battery is connected to the battery bus via the
battery-relay which is installed in the relay junction box behind the baggage compartment
frame.
The battery relay is controlled with the ELECTRIC MASTER key switch which is located
in the center of the instrument panel.
In addition, two 12 V, 7.2 Ah sealed-lead-acid batteries (ECU backup-batteries) are
installed behind the first ring frame as a further source of electrical power for the Engine
Control Unit (ECU B only).
Under normal operating conditions the ECU backup batteries are charged by the ECU
bus. In the event of an alternator failure and a depleted main battery the ECU backup
batteries automatically supply electrical power to ECU B via a 32 A fuse. This prevents
the engine from stopping in the unlikely event of an alternator failure and a totally
discharged main battery.
In addition, a non-rechargeable dry battery is installed in the IFR model as a further source
of power for the attitude gyro (artificial horizon) and the flood light. When the EMERGENCY
switch is set to ON, these two systems are supplied with power for 1 hour, independent
of all other electrical consumers. During each 100 hour inspection, this battery is checked
for proper functioning. Every 2 years or after use (broken seal on the switch) the battery
pack must be replaced.