Lead-Acid Storage Batteries
STORAGE, TRANSPORTATION, AND DISPOSAL
The storage of lead-acid batteries is fairly straightforward. Lead-acid batteries must be
stored in the open-circuit condition with the terminals insulated. Long periods of storage at
even low drain rates may result in permanent damage. Batteries should be stored in cool,
dry, environments in their upright position. To maximize the length a battery may be stored
it should be completely charged in the beginning. Batteries that will be stored for extended
periods should undergo regular open-cell voltage (OCV) checks and be recharged as
necessary or at regularly scheduled intervals.
An important consideration during storage is a damaging process called sulfation. As cells
sit in storage and self-discharge, the active materials of the electrodes convert to lead sulfate
just as they do in other discharges. But, in self discharge the lead sulfate forms as larger
crystals that have the effect of insulating the particles of the active material, either from each
other or the grid. Since lead sulfate occupies more space than sponge lead, the negative plate
expands in volume. If the cell is allowed to overdischarge, the lead sulfate may expand to the
point where it separates from the sponge lead and falls to the bottom of the jar as sediment.
The overall effect is a loss of capacity and greater internal resistance. Sulfation is normally
reversible for lead sulfate still attached to the negative plate by charging with a low current
until the lead sulfate is converted back into sponge lead.
Lead-acid batteries are regulated as a hazardous material by the Department of
Transportation (DOT) under 49 CFR 172.101. Under certain conditions a shipper may be
excluded from these requirements if the batteries and packing methods meet the requirements
of 49 CFR 173.159.
Disposal of lead-acid batteries should be performed according to all federal, state, and local
regulations. Lead-acid batteries should be reclaimed to avoid the regulatory requirements for
hazardous waste treatment and disposal facilities. Reclamation is required by law in some
The federal regulations governing reclamation are found in 40 CFR 266, subpart G. Persons
who generate, transport, or collect spent batteries, or who store spent batteries but do not
reclaim them are not subject to regulation under parts 262 through 266 or parts 270 or 124
of 40 CFR Chapter I, and also are not subject to the requirements of Section 3010 of the
Resource Conservation and Recovery Act (RCRA).