My '02 UL has a Lexus battery installed 37 months ago. Since it hadn't been driven for a few weeks (very unusual) I connected my charger and left it overnight. The battery was very low and didn't take a charge. I started it with a good size jump box, weak but started right up. Drove it to run errands, trying to keep it running at least 20 minutes in between stops. It started right back up, albeit not as strong as usual.

I hope it is just a battery and am open to suggestions. I wouldn't think it was the alternator because the charger didn't help. I will get it checked out tomorrow, just wondering if anyone had any thoughts.

I believe most powerful battery available for the car is the Interstate Mega-tron Plus with black top.

 

After charging for a few hours, check the voltage directly at the battery terminals.
If above 12.6, the battery is probably OK.
However, I would bet that it will be below 12.6, especially in view of the battery's age.
To confirm, check the voltage with the engine running. If it is above about 13.6, the charging system is probably OK.
Other things that might be a problem:
Battery terminals (especially the positive one).
Bad ground connection.
Leakage to ground (e.g. a fault in the wiring) - less likely.

 

I had the same problem. Bought a new battery. Two weeks later same problem. Shop checked alternator, any electrical leaks that could drain the battery. Alternator was on its last breaths. Changed alternator and battery - no problems yet.

 

I'm curious. What behavior led your mechanic so say the alternator was on its "last breaths"?

 

Update, the car was dead this morning. Started it with a jump box and stopped by an independent shop on my way to the office this morning. He had the Interstate Mega Tron battery in stock and was able to install in about 20 minutes. Although previous Lexus battery was under pro-rated warranty, I would have had to pay the dealer $60 to $70 for more portion plus a $50 labor charge. For about the same money, got the Interstate which is the largest battery available. It may not make a big difference but I got it done.

They tested the charging system and said the alternator was fine. A little skeptical of their test so we will wait and see on the alternator. Stay tuned.

 

With batteries bigger is not necessarily better. I'm a big fan of gel Optima sealed batteries. Anyway, I hope this solves your problem.

 

Actually for old school wet bath lead acid batteries - bigger and heavier is always better for both power and longevity. But newer types of batteries particularly AGM or lithium batteries are a different ball game in terms of how to judge quality and longevity.

For old school batteries, which is what I use, I'm a big fan of $85 Walmart Ever-start batteries - most are made by Johnson Controls (a quality producer), they are very well rated in CR testing, and have a 3 year full replacement non prorated warranty. Prorated warranties on batteries are completely worthless marketing BS.

btw - there are only a couple of factories left in NA that actually make lead acid batteries - all the numerous battery brands being sold today are basically same battery core with slightly different plastic case and label marketed at different price points by different retailers with lots of BS advertising.

 

The battery shop tests are usually good. They test the output under load - not the bearings and other physical things. They look for mid 14's in output voltage. Probably OK if they tested it. A resting battery should be around 12.6 volts or higher after sitting a few hours without charging or load. I like flooded cells better too - more forgiving of under and over charge. I buy from Interstate too. I've had good luck with them.

 

The batteries from Costco (Kirkland) and Walmart (Ever-Start Maxx) among others are probably a better value, have more than adequate capacity and have a very good warranty. The Costco and Walmart battery you have in install yourself (no Walmart Auto Center by me) which wasn't in the cards that morning. Their is something to be said for just getting it taken care of in about 20 minutes on a cold Monday morning before a holiday weekend and getting an electrical system test. The fact that they had the large capacity Interstate Mega-Tron Plus (24F) in stock was just a coincidental bonus.

 

Alternator was not charging at idle, only when rpm was over 1500 it charged the battery.

 

My experience with Lexus batteries from the dealership has been really poor, I definitely don't think they're worth the premium.

I've been doing well with Costco and WalMart batteries.I honestly believe they're better quality than what you get at the dealership, and the warranty is easier as well, just make sure you keep your receipts.

3 years though on a battery is about average, at least in my climate.

 

My understanding is heat is harder on a battery than cold.

My last battery in my LS lasted only 2 years - it went dead and was replaced last week. It had a 3 year replacement warranty so it didn't "cost" me any cash, but I did have a non starting car for 24 hours which really pissed me off. I arrived at the shop I bought it ( after a jump start ) and they didn't have time to put it in for me so I did it myself outside in the freezing cold.

Car batteries usually last me 5 - 7 years in Canada and my car sits in a heated garage during the winter. They told me it was just a bad build .... oh well.

 

My experience with Lexus batteries from the dealership was excellent. Purchased a new one at $120. When it died it was replaced at zero cost. The warranty started over (two year free replacement with the new battery) and when it died it was replaced at zero cost. Unfortunately, when it died I was on a trip and had to replace with a no name battery. It died within a year with no availability for replacement as that chain does not exit here. Then replaced with a Costco battery.

The only bad thing about the Lexus battery was the short lift, one to two years. But the dealer replacement was excellent. I would still be using one if the battery hadn't been replaced when there was no dealer available on the trip. Free replacement every two years is not a bad deal.

 

Um, that's sort of the main factor most people use when they evaluate a car battery. And 1-2 years is pretty crappy in my opinion for a battery that's nearly twice the price.

 

The stress on a battery from heat and from cold are different. In cold weather the battery has less capacity. At 20 degrees a 750 Cranking Amps battery may only have 500 Cranking Amps. In addition, your engine and oil are cold and some oils (not M1) are like molasses at cold temperatures making the job harder. In addition, some fuels vaporize more poorly requiring a longer crank cycle to start.
The problem with heat is that a hot battery may boil off electrolyte if too hot. This usually requires an Arizona like Summer heat plus some cranking to get the battery over 150 degrees (approximately - off the top of my head). In addition, hot plates are subject to possible buckling which can lead to shorts. Good separators help prevent this.

There are two battery manufacturers left here now (thank you EPA) Johnson Controls and Exide. The batteries are custom spec'd though by the retailers. You can tweak the alloy adding antimony (out of favor now), calcium or selenium. The plates can be thicker (deep cycle) or thinner with deep texturing (starting type). There is really a lot of engineering that can make for a better, longer lasting battery.
Oh, and yes, 2 years is way too short a battery life.