TM 11-6140-203-14-3
electrolyte resulting in damage to the battery. Do not adjust electrolyte level after a battery has discharged.
The correct electrolyte level cannot be determined when the battery has been discharged. Conversely, never
allow electrolyte to fall below the cell level indicators when the battery is in a charged condition. Low
electrolyte level in the charged condition will cause the cells to heat up, resulting in their destruction.
NOTE
An inherent characteristic of nickel-cadmium battery cells is that the electrolyte is absorbed within the
plates and separators to a point where it is not visible from the top of the cells when at a low state of
charge or in a discharged condition. When the battery is recharged, the electrolyte level rises and
reaches its maximum height at full charge. Ideally the electrolyte level should be checked on a fully
charged battery that has been at rest for 30 minutes. The correct level of electrolyte is 1/4 inch above
the top of the plates of a fully charged cell that has been at rest for the time specified in paragraph 5-4.
The procedure for checking the electrolyte level is exactly the opposite of that for lead-acid batteries in
which the electrolyte level is adjusted by adding water before placing the battery on charge, or whenever
the electrolyte level is low.
The maximum electrolyte level for a nickel cadmium battery is one-fourth inch above the top of the places.
Perform the following procedures for electrolyte adjustments:
a.
Before using the syringe, if necessary, modify it as follows:
(1) Use a sharp pin that has been heated with a flame from a match to pierce the stem of the
syringe one-fourth inch from the bottom of the stem (A, fig. 5-2).
(2) Let the pin remain in the stem for 2 or 3 minutes and then withdraw the pin slowly from the
stem.
b. Remove the fillercaps with the nylon wrench.
CAUTION
Do not spill electrolyte on the battery. Spilled electrolyte may cause corrosion of connectors and short-
circuiting between cells, resulting in damage to the battery.
c.
Use the stem-pierced syringe, filled with distilled water item 9, app E), insert the syringe into the
cell until it rests on the top of the plates (B, fig. 5-2). Slowly squeeze the contents of the bulb until the bulb is
empty or the electrolyte is just below the mouth of the cell. Avoid overfilling.
d.
Release the bulb to withdraw all liquid that is one- fourth inch above the top of the plates. if no
liquid is withdrawn, repeat c above.
e.
Repeat c and d above for all cells.
f.
Replace the fillercaps after the electrolyte level of all cells has been adjusted.
g.
Thoroughly wash out the syringe.
5-4
