Originally Posted by hotantivirus
Few days back, I left my car's reading lamp on and the battery got drained. I wasn't in town and my brother tried to jump start the car using cables and pushing the car but it didn't start, They sent the battery to a guy, who charged it. The car ran fine for a day until there was juice in the battery, after that it got shut off while running.
Tried to push the car, it started but however after 2 mins the RPM dropped to 0 and the car felt breathless and got shut off.
The car was serviced 3 months back and battery was changed around 6 months back.
What could be wrong? I'm yet to take a leave and get it checked my a mech. but the guy who charged my battery he said the alternator is faulty and he can get it fixed, but I ignored him.
Please get hold of a multimeter( it costs just 200 to 250 Rs),check the battery voltage without starting the car it should be above 12.2V. If the battery doesn't have enough juice, either get the battery charged and re-test or try a different method for checking the alternator. Start the vehicle and rev the engine to 2,000 RPM.
This will draw power on your battery, which should cause your regulator kick the alternator into high gear. Keep the engine running and retest the battery with the voltmeter.
When you read the voltmeter this time, the voltage should go up to at least 13. If varying the RPMs causes the voltage to fluctuate between 13 and 14.5 volts, your alternator is in good shape; if, on the other hand, the voltage remains the same or decreases, your alternator isn’t working properly.
Source:How to Check an Alternator: 9 Steps (with Pictures) - wikiHow