ction, preventing the flow of current.
Frequently, however, the circuit is not completely open, and the poor
connection acts simply as a high resistance. Under such a condition
the constant current generator automatically increases its voltage,
and forces charging current through the battery, although the latter,
having only a low fixed voltage, cannot force out the heavy current
required for starting the engine.

2. Terminals Broken Off. Inexperienced workmen frequently pound on the
terminals to loosen the cable lugs, or pry on them sufficiently to
break off the battery terminals. If the terminals and lugs are kept
properly greased, they will come apart easily. A pair of terminal
tongs is a very convenient tool. These exert a pressure between the
terminal and the head of the terminal screw, which is first unscrewed
a few turns.

3. Acid on Soldered Joints. Amateurs sometimes attempt to make
connections by the use of a soldering iron and solder. Solder is
readily dissolved by acid, not only spoiling the joint, but
endangering the plates if any gets into the cells. Solder must never
be used on a battery except for sweating the cables into the cable
lugs, and the joint even here must be well protected by rubber tape.

4. Defective Posts. Posts withdrawn from the post mould before they
are cool enough may develop cracks. Bubbles sometimes occur in the
posts. Either trouble may reduce the current carrying capacity or
mechanical strength of the post and result in a broken or burned-out
spot.

5. Plates Improperly Burned. As previously explained, this is not
likely to cause immediate trouble, but by imposing extra work on the
balance of the plates, causes them to wear out quickly.

Battery Discharged

1. Due to excessive use of starting motor and lamps.

2. Failure of generator.

3. Defective switches, which by being grounded, or failing to open
allow battery to discharge.

4. Defective cutout, allowing battery to discharge into generator.

5. Addition of accessories, or use of too large lamps.

6. Defective wiring, causing grounds or short-circuits.

7. Insufficient charging rate.

8. Battery allowed to remain idle.

Dead Cells

1. Worn out Separators. The duties of separators are to prevent the
plates from touching each other, and to prevent "treeing," or growth
of active material from the negative to the positive plates. If they
fail to perform these duties, the battery will become short-circuit