[utmanzai]

Yesterday, I found my battery dead when I tried to start my 2000 Avalon early in the morning. The battery was 2 years old. It was cold as hell too yesterday. I got a jump and went to the office. The battery was dead again by the end of the day. So I got another jump, went to Autozone to get a new battery (but didn’t install at that time) and ran some other errands. Today the car started in the morning with the old battery, no problem. Then at around 2PM I changed battery but I also did a couple of quick tests too. I started the car with the new battery, unhooked the hot terminal, and tried to turn the headlights on, the engine died on me. I repeated the same at a higher rpm, the engine died again. One extra thing I noticed this time was the flickering lights. But once I hooked back the new battery again, everything went to normal.
I feel my alternator is not working 100%. Any ideas?

Thanks!

 

[toyomoho]

AutoZone should be able test the old battery and I think the alternator. Suggest you not remove the battery terminals when the engine is running. The result can damage the alternator or other electronics! But since you did and the engine quit might be the alternator is dead.

Pickup a low cost (under $10) volt-ohm-milliamp meter. Check the battery voltage at the terminals with engine off. Should be 12.6-12.8v for a battery with a 100% charge. Start the engine and check the voltage again (battery cables still attached). The voltage should now be around 13.5-14.5V, as the alternator should be charging the battery (at a higher then battery voltage). If the voltage is the same as when the engine is off (or low), you have an alternator problem.

The new battery may be handling the load until it too goes dead.