Electrical System

Page 20

Previous | Table of Contents | Next

Volvo Bus Service and Maintenance Manual

30 Check the fluid level in all the cells. If necessary, add distilled water. Check that the batteries are fitted securely and the battery cables are not damaged.
31 Check the specific gravity with a battery hydrometer. If necessary, add distilled water.
32 Check the condition of the battery box and its attachments to the chassis. If necessary, lift out the batteries and clean the box and apply a protective coating of paint.
 Junction box, battery box
33 Remove the junction box cover. Check the electrical connections. Discoloured connections indicate poor contact. Remedy where necessary.


WARNING! Protect eyes and exposed skin when servicing batteries. Do not allow a naked flame near the batteries.

Correct fluid level is about 5 mm (0.2 in) above the cell plates. Check the batteries for the following indications of excess charging:

-Excessive gas from cells gives off an odour.
-Very low fluid level.
-Acid boil-over.
Graphic, battery

Clean the outside of the batteeries. Spray the pole shoes with rustproofing

Specific gravity of batteries at + 20°C

Battery fully charged1.28
Battery needs charging1.24
Replace batterywith more than 0.05 variation between any two cells

The specific gravity of the electrolyte gives a definite indication of the battery charge condition.

In the event the bus is difficult to start, check the batteries under load, see Service Manual, Section 3, Batteries and Alternators.

Check the date stamp on the batteries. Replacement of batteries older than 3 years is recommended.

Never mix standard batteries with so-called "freedom" or easy-maintenance batteries, since their properties differ far too much.

Graphic, battery care kit
(999) 9618 Battery care kit