Francis

Two days ago, my car couldn't started. Headlight and radio were not working. I didn't think much but went ahead to replace the battery. Now, the car starts just fine but I think the alternator could be weak.

I just bought the voltmeter and checked my new battery. It is 12.75 with the engine off and 14 with the engine on. I check my other car and it is 12.75 with the engine off and 14.23 with the engine on. Is my alternator (14 with the engine on) on the way out or still ok?

My 1st/2nd batteries (Toyota brand) lasted 5 years each and this 3nd battery (Lexus brand)only last 3 years? Thank you.

History:
1999 RX 300 fwd
Milage : 200k miles
Battery : 3 years old
Battery brand : Lexus
Alternator : still original

code58

The 14V running shoud be fine. I like to see about 14.2-14.5V but I normally test 'em with about 15-1600 RPM. 14V would not indicate a bad alterrnator at all. My guess would be that the battery was made by Johnson Controls (even though it says Lexus on it) and though they make about 80% of the batteries in the U.S. I personally don't think they're a very good battery. They have bought up quite a few battery manufacturers (effectively eliminating their comperition) that made far better batteries than they do and then replaced the production with their inferior batteries. I have used a # of JC manufactured batteries and have never had very good luck with them. It's hard to buy a good battery any more because JC bought up all the competition. My wife's '11 Camry has a JC maufactured battery and testing every couple of months tells me it's already on the decline.

bob2200

I also think 14v is just fine. Do you live in Southern California? I think heat is a significant factor in battery life.

I live in a moderate climate and replace the battery every 5-6 years whether needed or not. My mother lives in South Florida and gets less life out of her car batteries. But her Lexus dealer, I think, (JM Lexus) has a policy of replacing parts for free that previously failed and her last battery was replaced for free. Anyway, the Lexus battery is about twice the price of a Costco battery. I've been using a Costco battery since I replaced the original.

Francis

Thank you guys for your info. Yes, I live in Southern California. My RX had been a garage queen for her whole life but needed to park outside for the last 3 months because I have an additional car.... Thank you again.