2
Rev.12/31/97
1. CONDENSED INSTRUCTIONS: LEAD-ACID BATTERIES
1.1
1.1 PURPOSE
PURPOSE
The purpose of this section is to outline the duties and responsibilities for
routine operation and care of vented lead-acid batteries. Section 2 contains
routine operation and care of vented lead-acid batteries. Section 2 contains
detailed information on lead-acid battery principles.
1.2 BATTERY CHARGING AND SPECIFIC GRAVITY TEMPERATURE CORRECTION
1.2 BATTERY CHARGING AND SPECIFIC GRAVITY TEMPERATURE CORRECTION
A. Initial Freshening Charge
A. Initial Freshening Charge
To establish a reference, give each new battery, or reinstalled battery stored
for more than 3 months, an initial freshening charge. Use the equalizing
for more than 3 months, an initial freshening charge. Use the equalizing
voltage given by the manufacturer for the type cell, but do not exceed the
maximum voltage of other loads connected to the charger. Apply this charge
until each cell gasses freely and equally and specific gravity (sp.gr.) stops
maximum voltage of other loads connected to the charger. Apply this charge
until each cell gasses freely and equally and specific gravity (sp.gr.) stops
rising. Just before the end of the initial charge, record the voltage of each
cell. About 20 minutes after the end of the charge, record the specific
gravity of each cell, corrected to 77 EF. For every 3 EF above 77EF, add one
point (0.001) to the reading. For every 3 EF below 77EF, subtract one point
(0.001) from the reading. Use form POM-133A for these records and keep
them for the life of the battery.
them for the life of the battery.
A.1 Pilot Cell.--
A.1 Pilot Cell.--After the initial charge or to begin a yearly cycle, choose a pilot
cell from one of the lowest specific gravity and lowest voltage cells. This cell
is used as a representative for readings, for one year. Each year a new pilot
cell is chosen.
is used as a representative for readings, for one year. Each year a new pilot
cell is chosen.
B.
B. Float Charge
Float Charge
Charge batteries continuously at the float voltage recommended by the
manufacturer
manufacturer
. Monthly
y take the voltage across the overall battery terminals
with an accurate digital meter and compare this reading with the charger
and bus voltmeters. If needed, adjust the charger float voltage based on the
digital
meter. Adjust the charger and/or bus voltmeters to agree with the
digital meter if needed.
A battery is said to float when charging voltage is slightly greater than the
open circuit voltage of the battery. Floating current required to keep lead-
calcium cells at full charge is about one-fourth to one-third that of lead-
antimony cells, but lead-calcium cells usually must be floated at a slightly
higher voltage. Lead-selenium cells require float voltages slightly above
those of lead-calcium.
calcium cells at full charge is about one-fourth to one-third that of lead-
antimony cells, but lead-calcium cells usually must be floated at a slightly
higher voltage. Lead-selenium cells require float voltages slightly above
those of lead-calcium.
The operation of a battery by float method is based on overall voltage applied
to the battery terminals. The voltmeter used must be very accurate. An
inaccurate meter can result in either over or undercharge and resulting
problems, which reduce life and service of the battery. See section 1.3.
to the battery terminals. The voltmeter used must be very accurate. An
inaccurate meter can result in either over or undercharge and resulting
problems, which reduce life and service of the battery. See section 1.3.