Battery Dead 2nd Time In 2 Weeks

[Gumart1]

My 36 month old battery died 2 weeks ago on my '98LS400. I hadn't driven the car for about 5 or 6 days. I suppose I could have jumped the car, but I removed the battery and had Lexus test it (no charge), and the battery tested fine. They charged it overnight for me for free and made sure it held the charge. I thoroughly cleaned the dirty battery and terminals with baking soda, and cleaned the housing too. When I re-installed the battery I noticed the an interior passenger dome light was on, which I assumed was the culprit. I drove the car that night for about 30 miles, and then the car sat for another 5 days. I noticed after the third day when I opened the door that the interior lights were dim but not dead, and 2 days later it is completely dead again. I know for certain this time that nothing was left on. What is causing the battery to slow drain like this?

[zigenfiver]

Do you have any amps hooked up incorrectly or anything connected directly to the battery? Make sure the battery clamps are tight, sometimes if those are loose the battery will not charge correctly. Alternater?

[spiller91ls]

maybe you need a new bucket of amps???

Make sure that your battery is charged up and let the car sit for a couplce of days. Then pull the negative side off the battery and slowly put the clamp back on. If you see a spark jump, then you have a current draw someware in your car, all you can do is start searching for the source. you can do it any time, 1st 2nd 3rd 4th day etc.

[TexasLexus94]

Anytime I have a problem with a battery over 2 years old, I replace it. Name anything else you can repair on a Lexus for 50 bucks or so. Not much.

Then, if the new battery fails, you know you have a problem other than the battery. And the new one is still A-OK.

3 years isn't a bad life span for a battery, based on my experience. My Honda had 3 batteries in 5 years.

[Gumart1]

I agree, from experience, and from reading many posts, that all batteries regardless of brand usually last about 3 years. I actually first had Autozone test the battery and they said it was bad. Then, I took it back to Lexus who were about to sell me a replacement under warranty for a discounted $43, since the battery has an 84 month warranty. But when they tested it, they showed that it passed, and claimed that they couldn't sell a new battery if the old one tested good. I misplaced the report, but it did show that it passed, plus it was charged overnight by Lexus and held the charge for a day there until I picked it up. I am going to another Autozone today to have them test the alternator, and at least rule that out.

[TexasLexus94]

I had a dead battery in my Honda, which I seldom drove, took it to the dealer, who charged me to recharge it, because he said the battery was OK. At that time, I could or should have gotten a free replacement battery per the warranty. Stupid me-2 months later the battery crapped out totally-beyond the replacement period. Didn't even have a pro-rata warranty. Duh.

So 4 months ago, the Lexus wouldn't start. Jumped it, went to AutoZone, put the new one in, gave them the old one, and drove away. No hassle, no BS. 50 bucks. If it had not performed after the new battery, then I would have gone to Plan B. But it was peachy.

Oh, and stay away from the Dealer (Stealer) unless you like being stripped naked for your last dime.

Bet your alternator is A-OK, too.

[Gumart1]

TexasLexas, that sucks to hear about what the Dealer did to you. Well at least Lexus didn't charge me anything to recharge the battery, but they did give me a printout which showed good voltage and a successful load test. Is it possible that although it test good, the battery still is not good? Anyway, I know any brand battery might take care of the problem but I prefer to have genuine parts, it just looks nicer if I resell. Especially if I can get the prorated price of $43 for the Lexus battery, that would be great. If it really is the battery, I'm hoping that Autozone will print something that I can bring back to Lexus. I wonder if Lexus is trying not to honor a warranty. After all, even they know that no battery will last 84 months. Once I check the alternator I'll be more certain. Of course there could be other reasons for the battery drain, but I won't go there yet.

[TexasLexus94]

You have a newer Lexus, and are just starting to encounter the reality of a used Lexus. The members of this forum who have Gen 1 Lexi are incredibly helpful, because they know that we all will inevitably face major repair costs, whether due to wear and tear, or due to design errors, such as Gen 1 power steering problems. For example,my Lexus was burning up power steering fluid, and I found out how to fix this problem for less than 100 bucks. God knows what Lexus would charge-certainly more than 1G. When I found that my repair resulted in a light staying on in the dash, I fixed that problem with the help of "Lexls", a major contributor.

My point is that, if you are afraid to sell a car without oem parts, I'd think that you will pay a lot more over the years-especially if you use the Lexus dealer. I went through the load test stuff, too, but later when I parked the car at the airport for a week, the battery failed again-for good. The point is that the load test checks for holding an immediate load, but with all the security and other systems that drain a parked battery slowly over weeks, the battery will then fail again, and the dealer will act stupid. Which is a required course at Lexus, I believe. Money 101.

[mickg]

Gumart:

I would suggest you take your multimeter, and check charging voltage, which should be above 14 volts, with engine running and all accessories off. Leave the engine idling and come back in 10 minutes, and make sure the voltage regulator is doing its job and keeping the overvoltage at 14 or better.

Then shut it down, and place the ammeter into the battery circuit, and see what the current drain is for security system, etc. Take the battery amp/hour rating and divide by the drain rate; this will give you a rough clue to how long you should expect a new battery to last. I'm not sure what the factory spec would be, but I leave my '94 at the airport for weeks on end, and the electrics work fine.

I once installed a refurbished alternator that checked out fine on the bench, and installed, however as it warmed up, it lost voltage until the car ran on battery alone until there was insufficient electrical power to keep the ignition and accessories going. I died a number of freeway deaths until I figured that one out.