nmnunna32

sorry long story...

Last week my 2010 rx350 started to have starting problems. Eventually i had to jump start it. Battery is original oem which is already 5 years old. I got it load tested at sams club, to my surprise the tech said the battery checked out good and suggested that i get the charging system checked out at autozone. Autozone also said battery is in good condition but alternator is bad.

I took it to lexus dealer (i have lexus extended warranty). My service advisor said the tech has checked everything battery/starter/alternator/parasitic-draw and they did not find any problems. He suggested that i replace the battery as it is old and could be the reason for the root issue.

I went back to samsclub and got my battery replaced. (duracell)

After getting the battery replaced: (it has been about 4 days)

I have not seen any starting problems but as autozone said my alternator is bad and having trouble to charge my battery I am still not fully convinced that i addressed the root cause so I kept checking my battery voltage. When engine and everything electrical related is off I read 12.6v which i believe is perfect (form other posts in this forum). However, when the engine is running and lights are off, I read about 13.3v. Based on other post i should see any where between 13.8 to 14.2v. This is what bothering me.

anybody know if 13.3v is still good charging voltage or do you think i should get my alternator rechecked?

Thanks for reading my post.

Clutchless

What accessories were running when you checked the voltage? Everything should be off. If you want another opinion, I would go to a good independent mechanic or a different Auto Zone. I bet your alternator is just fine. In years of doing my own repairs I learned the simple obvious fix is usually correct. Batteries are known to wear out and at 5 years it was time to go before winter.

I also have a 2010, with only 40,000 miles but just replaced my OEM battery after draining it listening to the radio for 40 minutes. It charged back up, but with winter coming, it was time to replace it. I will try to remember check my voltage this week.

GSteg

iTrader: (15)

Measure the voltage output at around 2,000 RPM. Most alternators do not provide maximum output at idle.

ThChinaman

Battery voltage should be between 12.6v to 12.8v. When charging without load, it should be between 13.2v and 14.8v. I pulled those numbers off of the service data from Toyota TIS a while back.

nmnunna32

Thank you ClutchLess, Gsteg and ThChinaMan!