Piper Navajo PA-31 Service Manual page 754

PIPER NAVAJO SERVICE MANUAL
11-81. CHARGING BATTERY. When recharging the battery, it should be removed from
the airplane. (Refer to Paragraph 11-78.)
a. Remove cell caps and check fluid level.
b. Begin charging rate at 2 amperes and finishing with 1 ampere.
c. Should the battery boil over, clean per Paragraph 11-80.
d. When battery is completely charged, reinstall in the airplane.
11-82. STARTING THROUGH EXTERNAL POWER RECEPTACLE WITH AIRPLANE'S
BATTERY NEARLY DEPLETED.
NOTE
Should the hydrometer reading indicate less than 1190, the
battery should be removed and recharged or replaced.
a. When using a 24-volt battery for external power starting and the airplane's battery is
nearly depleted, the following procedure should be used:
1. Disconnect the airplane's battery at the negative terminal to prevent excessive
loading of the external starting battery.
2. Check that all of the airplane's electrical equipment and master switch are
turned off.
3. Connect the external battery to the external power receptacle and start RIGHT
ENGINE ONLY using normal starting procedures.
4. Remove external battery and then reconnect airplane's battery at the negative
terminal.
5. Turn master switch on and check ammeter for battery charging current.
b. When starting with a power cart and the airplane's battery is nearly depleted, the
procedure in step (a) need not be followed. The capacity of a power cart is sufficient to
start an aircraft with a low battery. If a six-volt battery is available, it can be connected in
series with the 24-volt external battery to supply 30-volts for starting. In this case, use the
same starting procedure as used with a power cart.
CAUTION
In the event it becomes necessary to start the engines through
the external
power receptacle, due to a low battery
condition, ascertain that aircraft battery is on the charging
line by monitoring the battery ammeter (charging current
will be high). Do not take off until charging current falls
below 20 amps.
When connecting batteries in series as outlined in step b,
never use a 12 or 24-volt battery in place of the six-volt
battery since electrical damage may result.
ELECTRICAL SYSTEM
Reissued: 10/12/79
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