Rockwell Commander 112 - Page 209

SECTION X
ELECTRlCAL
MAINTENANCE MANUAL
ROCKWELL
COMMANDER
ll2/B/TC/TCA
Check voltage and polarity of external
power source before connecting power
source to aircraft.
BATTERY SERVICING. Initial servicing of a dry
charge battery is as follows:
a. Remove filler plugs and fill each cell with
diluted sulphuric acid (1. 250 to 1. 265 specific grav-
ity), to the bottom of the filling tubes in the battery.
Use only glass, rubber or plastiC materials for con-
taining battery electrolyte fluid during servicing,
TYPE (Rebat)
AMPERES
ELECTROLYTE
VOLUME (QTS.)
S-25
2
2.
1
R-35
3
2.5
Figure 10-1. Battery Charge Rates
and wear protective clothing and rubber gloves when
handling
electrolyte to prevent personal injury. Use
a solution of baking soda and water t9 neutralize any
acid spilled on clothing, skin or any damageable sur-
face.
b. Locate battery and charging equipment in a
well ventilated area before initiating charge. Con-
nect battery charger to the battery, and observe
proper polarity (connect battery positive terminal
to charger positive circuit).
c. .' Charge battery at rate shown'in Figure 10-1.
Do not exe eed this rate or electrolyte gassing will
occur.
10-2
Gasses given off by a battery under
charging conditions are flammable.
SPECIFIC GRAVITY
CHARGED
RECHARGE
1.265 - 1.285
1. 250 - Less
Figure 10-2. Hydrometer Readings
d. Check battery with a hydrometer when it will
no longer accept a charge. Hydrometer reading
should be 1.265 to 1. 285 at room temperature of 70
to 80 degrees F. Battery voltage should be 14. 4
v.olts with
zero load on battery. Check security of
terminal connections, and battery charger output
voltage if hydrometer check indicates a level below
1. 265.
e. All cells must have a specifiC gravity reading
between 1. 265 to 1. 285 with electrolyte level at bot-
tom of filling tubes (see Figure 10-3). If hydrometer
indicates a high gravity reading, remove a small
amount of electrolyte and add distilled water. Repeat
as necessary to achieve proper specific gravity level.
If individual cell reading is low, add higher gravity
electrolyte instead of distilled water.
SERVICING BATTERY INST ALLED IN AIRCRAFT.
The l2-volt battery is installed in the left side of the
tailcone, and is accessible through the baggage com-
partment (see Figure 10-3). Loosen and remove the
battery box cover for battery inspection and electro-
lyte level checks.. A built- in plastic carry strap is
provided fo r cOllvenience in handling the battery if it
becomes necessary to remove it from the battery box.
Check the battery electrolyte level frequently, espe-
cially during hot weather. If visual check shows low
cell level, and no electrolyte is available at this time,
add distilled water to bring the cell(s) up to proper
level. However, addition of water may result in as
much as a 15 point difference in specific gravity
reading. between cells not serviced and those receiv-
ing water in place of electrolyte.
5
1. ELECTROLYTE LEVEL INDICATOR
2. NEGATIVE TERMINAL
3. VENTED FILLER CAP
4. CARRY STRAP
5. POSITIVE TERMINAL
X 210 1
Figure 10-3. Battery
Copyright Commander Owners Group 2013 All Rights Reserved
**unofficial copy**