4841 electrical battery. kavit jay

This week in class we went through the function of the battery.The battery supplies voltage to the starter motor to turn over the engine, and also provides voltage to the electronic components which maintain the electrics in the vehicle while being driven

Inside the battery there are 6 positive and negative cell plates and in between separating the two plates are called ribs so there is no contact between them.

Inside the battery there is an acid called sulfuric acid h2so4 this acid is highly dangerous and can burn through cloths and skin always wear eye protection and overalls.

04/05/2011
            
 In practical class we carried out a battery service test

Visual check

We first checked for any loose connections and corrosion around the battery which could result in high resistance.

Electrolyte levels

We then moved on to checking the electrolyte levels in each cell, all the cells had a reading around 1.200 to 1.275 which was in the green colour level indicating (GOOD).

OCV voltage

We then carried out an OCV test using a multimeter set on 20v and obtained a reading of 13.9v this reading means that there was surface charge on the engine which needed to be removed by sustaining a load on the battery; this is done by cranking the engine or leaving the fan running for a minute.

The reading we then got was 12.8v which is a fully charged battery 100%.

Checking colour and gavity variation

cell	1	2	3	4	5	6
reading	1.275	1.250	1.225	1.250	1.225	1.200
colour	clear	clear	clear	clear	clear	clear

These are the readings we received after the test as above, this shows that there was some different electrolyte levels and needed to be filled with battery water to a level of 1.275 roundabouts. Our gravity variation is 75 and the specs are 25-50, which is above the specs

Load test

we then moved on to a load test we fist connect the volt meter to the battery to receive reading under the load, then we connected the load tester to the battery and cranked the amps to half of the batteries CCA which was 300 so we set it to 150amps for 10 seconds.

We got a reading of 10.4v under 150amp load on the battery which meets the specs of above 9.5v that an ordinary battery should hold.