Battery; Purpose; Location; How It Works - Toro TX525 Service Manual

Battery

Purpose

A battery supplies the energy source required to activate
the starter motor to spin the engine so it will start. It
also supplies the energy required to power the various
electrical circuits in addition to the alternator.

Location

The battery is located inside the rear frame cover on the
right side (Fig. 0828).

How It Works

The battery is the main power source for the electrical
system. The typical battery is made up of plates of lead
and separate plates of lead oxide which are submerged
into a electrolyte solution of 35% sulfuric acid and 65%
water. This causes a chemical reaction that releases
electrons which flow to produce electricity.
TX525 Service Manual
Fig 0828 PICT-5624

Testing

You must first have the battery fully charged prior to
any test. The surface charge must be removed before
testing. To remove surface charge the battery must
experience a load of 20 amps for 3 plus minutes.
No-load battery testing is done with a hydrometer/refract-
ometer or digital voltmeter. A calibrated (numerical)
hydrometer is more accurate than the floating ball type.
The hydro-meter/refractometer indicates the battery
state of charge by measuring the specific gravity of
the electrolyte. The voltmeter indicates the open circuit
voltage of the battery, another indication of the battery's
state of charge.
The reading on the digital voltmeter should be the
voltage shown in the following table. If you have voltage
readings in the 10.5 volts range on a charged battery,
that indicates a shorted cell.
State of Charge
100%
75%
50%
25%
Discharged
The no-load tests do not tell you the capacity of the
battery - that is, how many amps it can deliver over a
period of time for this, a load tester must be used. A load
tester removes amps from a battery much like starting
an engine would. The battery may have a label with the
amp load for testing and/or a Cold Cranking Amp (CCA)
rating. The load test number is 1/2 of the CCA rating.
For example, a 500 CCA battery would load test at 250
amps for 15 seconds. A load test can only be performed
if the battery is near or at full charge.
If you have a maintenance free battery, the only ways to
test are with a voltmeter and/or a load test.
Rev. 000
ELECTRICAL
Specific Gravity Voltage 12V
1.265
1.225
1.190
1.155
1.120
12.7
12.4
12.2
12.0
11.9
5-17