off flush with the top of the cover with a hack
saw after the cell connectors have been drilled off. The drill is then
used as before to release the grip of the washer. Using a drill to
release the grip of the washer makes it necessary to build up the
posts when the battery is reassembled. Instead of using an ordinary
twist drill, a special hollow drill may be obtained from the Universal
Battery Co. This drill cuts away the lead sleeve gasket without
injuring the post. If an ordinary drill is used, a 3/4 inch drill is
required for the seven plate battery and a 13/16 inch drill for all
other sizes.

ONE-PIECE BATTERY CONTAINERS

The standard practice in battery assembly has always been to place the
plates of each cell in a separate, hard rubber jar, the jars being set
in a wooden box or case. Each six-volt battery thus has four
containers. When a wooden case is used, jars made of rubber, or some
other nonporous, acid-resisting material are necessary.

[Fig. 292 One-piece battery container]

Wooden cases have been fairly well standardized as to the kinds of
wood used, dimensions, constructional features, and to a certain
extent, the handles. The disadvantage of both the wooden case and the
iron handles is that they are not acid proof. Acid-proof paint
protects them from the action of the acid to a certain extent, but
paint is easily scraped off, exposing the wood and iron to the action
of the acid. It is practically impossible to prevent acid from
reaching the case and handles, and corroded handles and rotted cases
are quite common.

A recent development is a one-piece container which takes the place of
the jars and wooden case. Such a container is made of hard rubber or a
composition of impregnated fibre which uses a small amount of rubber
as a binder. These cases are, of course, entirely acid proof, and
eliminate the possibility of having acid soaked and acid rotted cases.
Painting of cases is also eliminated. The handles are often integral
parts of the case, as shown in Fig. 292, being made of the same
material as the case.

The repairman should not overlook the possibilities of the one-piece
containers. In making up rental batteries, or in replacing old cases,
the one-piece containers may be used to advantage. These containers
are suitable for Radio batteries, since they have a neater appearance
than the wooden cases, and are not as likely to damage floors or
furnishings because the acid cannot seep thr