Maintenance And Charging; Hazard Of Short Circuits - Teledyne 913 Installation And Operation Manual

Power Products Guide
Section 2 Batteries
2.5.3 Maintenance and
Charging
2.5.4 Hazard of Short
Circuits
2-14
meters, pumps, and other equipment. These batteries are quite
large compared to the standard Isco battery packs, so you must
mount them separately from the equipment they are powering.
Mount wet cell batteries securely so they cannot tip over. This
is important because the acid in the electrolyte is both corro-
sive and toxic.
Connection between battery and equipment is with a special Isco
cable. This cable has a two-pin M/S connector on one end and two
large alligator clips on the other.
The positive clip (+) has red shrink tubing on its wire to correctly
identify polarity. Verify polarity with a meter. Attach the clips to
the proper terminals on the battery and plug the M/S connector
into the instrument.
Keep the terminals on the battery posts clean at all times.
Lead-acid batteries are notorious for "growing" corrosion on the
battery posts. These deposits will rapidly cause the conductors to
fail if allowed to form for any length of time. You can easily
identify the corrosion as white flakes or powdery deposits. Cor-
rosion on the terminals also can creep into the attached alligator
clips, especially the positive one. These deposits are harmful
because they will eventually corrode the metal (conductive) ele-
ments of the circuit completely away and because they form good
insulators when dry. Grease, baking soda, and corrosion-inhib-
iting felt washers (available from auto-parts suppliers) are all
helpful in keeping the connections between the battery and the
cable reliable and corrosion-free.
If the battery is not the sealed type, you should check the level of
the electrolyte in each cell every time you recharge it. Unsealed
batteries have caps on top of the case that you can remove to
check the electrolyte. Add only distilled water according to the
battery manufacturer's recommendations; never add common
tap water or more electrolyte. You can check charge condition
and the condition of each cell with an ordinary battery
hydrometer, a device that measures the specific gravity of the
electrolyte. Follow the battery manufacturer's recommendations
for charging the battery. An automotive-type charger is usually
satisfactory for charging these batteries. Isco chargers are
designed for batteries with low ampere-hour capacities; their use
in this application is not recommended.
As advised for the nickel-cadmium battery, do not check the
charge condition of either lead-acid or gelled-electrolyte batteries
by "sparking" the output cables (momentarily shorting the wires
together). These batteries, when fully charged, can deliver large
amounts of current into a short circuit fault, especially if the
short is close to the battery. While the current may not be as high
as a nickel-cadmium battery, it is still considerable. Unlike
nickel-cadmium batteries, lead-acid batteries are not internally
CAUTION