Here, as with connectors, the type of terminal determines the cleaning method. Copper-inserted terminals and
posts are usually cleaned with an abrasive pad or plastic bristle brush as previously described. Wire brushes are
not to be used. Removal of the thin lead plating can occur, leaving the copper underneath exposed to corrosion.
When multiple personnel are involved, consistent cleaning methods and techniques will assure consistent
battery-wide connection resistance readings.
Assembly Hardware
In a large number of applications, assembly hardware takes the form of stainless steel. It is frequently type 18-8
or 316 with the latter of the two having higher nickel content. This results in a higher resistance to corrosion.
Type 316 is generally the metal of choice for batteries employed in high rate applications. This particular
hardware identified with the numbers “316” stamped on bolts, washers and lock washers. Otherwise, if
stainless, it will be 18-8 or other stainless.
Lead encapsulated brass nuts are also used in combination with a threaded brass stud. These are generally
found on VLA batteries used in telecommunications and small switchgear batteries where lead alloy posts and
lead plated connectors are used.
Galvanized steel hardware should be avoided as it is subject to corrosion and causes galvanic corrosion when
used with lead and copper.
Regardless of metallurgy, nut/bolt hardware is not intended to be greased prior to assembly unless the
installation instructions specifically indicate. Torque specifications are based on un-lubricated threads.
Corrosion Inhibitors
From the title of this section, one might surmise that some level of corrosion, hence connection degradation
may become a maintenance issue. Not all battery manufacturers prescribe the use of corrosion inhibitors. The
installer should consult the installation manual. As to just how much of a maintenance issue, the battery
person’s universal response to that is “it depends” and it is absolutely the truth. The basic premise of using a
corrosion inhibitor is to provide an oxygen seal around the connection the installers spent hours cleaning and
assembling. Preventing electrolyte attack is the goal. Use of these compounds, along with proper surface
preparation aids in maximizing the time connections remain within specification before they must be
disassembled and reworked.
One of two types of corrosion inhibitors are applied to connections used on lead-acid batteries. Keep in mind
that a specific battery manufacturer may not require its use. Corrosion inhibitors include No-Ox-Id Type A grease
(aka No-Ox) and NCP-2 from NoCo. The author’s use of the brand names is not a product endorsement. Both
have been on the market for many years with No-Ox being in use the longest. Usually, one of these will be
provided in the battery system accessory kit.
There are numerous ways to apply these products. No-Ox grease can be applied directly from the container to
the battery terminals and connectors. A thin, uniform film is all that is necessary. Coating the entire length of an
intercell connector is not recommended. Installers will run out in short order. The extra grease application is
unnecessary and serves no useful purpose. Application should be limited to the portion of the connector that
actually contacts the battery terminal. Another method recommended by some manufacturers is to heat the
grease to approximately 160°F (71°C). This results in a somewhat thick consistency. Connector ends are dipped
into the hot grease, providing a uniform, but fairly thick coating. With cell/unit terminals properly cleaned and
ready for assembly, the connector(s) are attached using the supplied nut and/or bolt and washer hardware.
Note that No-Ox grease has a minimum flash point of approximately 450° F (232° C). Extreme caution should be
exercised to avoid a fire when heating the grease.
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