Cleaning The Battery; Testing A Battery; Generator Revolving Field Brushes - Hobart Jet-Ex 5D Operation And Maintenance Manual

OM-2094 / Operation and Maintenance Manual
Jet-Ex 5D / Spec. 7500285/ Generator Set
mix the water and the electrolyte, or damage to the battery will result from the water freezing.
e. Cleaning the Battery
If the top of the battery is dirty, it may be cleaned with a brush dipped in ammonia or soda solution.
Disconnect lead connectors from battery posts. Vent plugs should be tightened to prevent cleaning
solution from entering cells. Clean battery as required, using brush and cleaning solution. Flush off
the battery with clean water. Special terminal cleaning tool. Make certain that vent holes in filler
caps are not clogged.
f. Testing a Battery
Tests are made on a battery to determine the state of charge and also its condition. The results of
these tests show whether the battery is good, needs recharging, or must be replaced. If a battery
has failed, is low in charge, or requires water frequently, the reason for the condition must be found
and corrected. Visually inspect the battery before testing, to determine if it has been damaged.
Moisture on the outside of the case, or low fluid level in one or more cells indicates possible battery
damage (cracked case, etc.). The battery may be tested by two methods. A battery-starter tester
may be used to determine the battery's ability to deliver current. A battery hydrometer test
determines the charge condition of the battery.
(1) Battery-Starter Tester
Connect battery to the tester according to instructions furnished with the instrument. Test
battery according to tester instructions. If the test determines that the battery has acceptable
voltage, this indicates that the battery has output capacity and will accept a charge if required.
(2) Hydrometer
Remove filler caps and check the specific gravity of the electrolyte in each cell. If specific gravity
is 1.230 or below, add water if necessary and charge the battery until it is fully charged. A fully
charged battery will give a specific gravity reading of 1.265 to 1.285. The specific gravity of a
fully discharged battery may range from 1.140 down to 1.120.
NOTE: The battery is fully charged when all cells are gassing freely, and the specific gravity ceases to
rise for three successive readings taken at hourly intervals.
a. If the battery starter test indicated that battery voltage was below the acceptable voltage
value, test each cell with the hydrometer. If the difference in specific gravity readings between
any two cells is 50 points (0.050) or more, the battery isn't satisfactory for service and should
be replaced.

Generator Revolving Field Brushes

Figure 4
Chapter 2-2
Page 6
A-Leads
B-Brusholder Caps
C-Brusholder
D-Brush
E-Slip Rings
November 1, 2000
Revised 08/01