Electrical System
347
Battery Testing
Always wear a face shield, gloves, and protective clothing when servicing
batteries. Lift batteries with handles or proper lifting devices.
Be sure all cables are disconnected from batteries before conducting
tests. See cable disconnect information in the “Disconnecting/Removing
the Batteries” section of this chapter.
Visual inspection alone is not adequate to determine if a battery is serviceable. Following are three ways
to test the batteries in your bus.
Carbon-Pile Load Test
This test may be performed with the battery in or out of the vehicle. This information is provided as a
guideline only. You should follow the instructions of the manufacturer of the carbon-pile load tester.
1. Make sure the battery disconnect switch is in the OFF position. Disconnect battery cables start-
ing with the ground cable.
2. Connect a carbon-pile load tester across the battery.
3. Connect a voltmeter across the battery.
4. If the carbon-pile load tester does not have an accurate built-in ammeter, connect an ammeter in
the carbon-pile load tester circuit.
5. Using the carbon-pile load tester, place a 100 amp load on the battery for 10 seconds to remove
the surface charge.
6. Turn off the carbon-pile load tester and read the open circuit voltage on the voltmeter. It must be
12.4 volts or above. If the voltage reading is below 12.4 volts, charge the battery and start again
at step 1.
7. Using the carbon-pile load tester, place a load equal to one half the battery’s rated Cranking Per
-
formance (specified on the battery) or three times the battery’s 20-ampere-hour capacity, for 15
seconds.
8. The voltage reading must be at least 9.6 volts at the end of the 15 seconds under load.
9. Ensure that both of the batteries have an equal charge before placing the bus in service.
If the battery does not pass the above test, it is not serviceable and should be replaced.
Summary of Contents for LOW FLOOR
Page 18: ...Specifications 18...
Page 58: ...Preventive Maintenance 58...
Page 110: ...Engine 110...
Page 138: ...Transmission Driveline Rear Axle 138...
Page 182: ...Suspension 182...
Page 260: ...Air System 260...
Page 420: ...Electrical System 420 Deutsch DT Series Connectors...
Page 421: ...Electrical System 421...
Page 422: ...Electrical System 422 Deutsch HD 10 Series Connectors...
Page 423: ...Electrical System 423...
Page 424: ...Electrical System 424 Deutsch HD 30 Series Connectors...
Page 425: ...Electrical System 425...
Page 442: ...Heating Air Conditioning 442...
Page 492: ...Body and Interior 492 Figure 11 33 USSC Seat Assembly...
Page 493: ...Body and Interior 493 Figure 11 34 USSC Seat Suspension Assembly...
Page 495: ...Body and Interior 495 Figure 11 37 Seat Air Connections...