markr346

Our '06 RX330 has not started a couple of times in the past few months. The battery (replacement - 9 months old) is almost brand new. Near as I can tell, there are no lights on, outlets in use, etc. etc. etc. When I jump it, it starts right off, so the battery seems to be fine. We parked the car in the garage Friday night, and tried to start it Tuesday morning - no driving in between. Anyone run across any problems with "something" draining the battery of its juices? Any tips would be appreciated. We're 200 miles from the nearest dealer, and would like to avoid a trip in for warranty/service.

jfelbab

Defective battery or faulty charging system. Most likely a battery issue, IMO. Several automotive stores will do a load test of the battery for free. Check AutoZone, Advanced, CarQuest type stores to see if they will test it.

Lil4X

There have been several such issues here recently. Jim's diagnosis is a good one, I'd suspect the battery too.

Another way to prevent discharges is to install a shut-off switch like this.


Photo courtesy www.amazon.com

That little wire with a knot in it is a jumper that can be installed across the switch with a fuse in it to prevent the use of the starter when the **** is unscrewed a turn or removed. I put one of these on JK's minivan as an anti-theft device, and she's delighted with it. Simple and safe.

On the RX that has so many memories to maintain, I'm going to play around with different fuses. A 15A fuse is stock, but I want to put an ammeter across the contacts to see what the normal draw is. If I could substitute, say a 3A fuse, sufficient to retain computer memory and allow me to open the door, activating the dome lights, etc., maybe I could prevent a short in the system (outside the battery) from discharging it into uselessness. Something to think about. . .

Grumpa72

After you had to jump the battery the first time, did you put a charger on it? The one thing I see often is folks just driving around and letting the alterhator charge up the battery. I have always told family and friends that you need to put the battery on a charger for 4-6 hours after a deep discharge resulting in a no-start condition. Alternators simply are not designed to give a deep cycle charge to a battery.

If you have charged your battery, then I would suspect a charging or battery problem. With a fully charged battery, the voltage should be 12 volts, plus or minus a bit. With the engine idling, the alternator should be in the 14 volt range. I don't know the exact numbers for Lexus, but those are close.

lexuslover

maybe there is something wrong with the alternator then? i have never encountered the problem you are describing, but if you've already had the battery replaced once, i doubt it's the battery.

ours died once when we accidentally left something open, but after a jump and driving it around a bit it never failed to start. in fact, nowadays it's our weekend car only and it regularly sits for 1-2 weeks without any driving and it starts right up... i am not even certain whether we've had to change the battery since we bought it in March 03, its about 5 years old with 67k miles.

it definitely shouldn't die from leaving it undriven from a Friday to the next Tuesday...

salimshah

since the jump starts the RX, that clearly shows that the battery does not have enough juice.

That leads to couple of possibilities:
1 Battery is draining.
2. Alternator is unable to charge sufficiently [either charging is low or duration of engine running is too short. Try Grumpas overnight charge suggestion to eliminate the later].
3. Battery is defective. Have it checked per jfelbab

To reduce battery drainage do couple of things ... Switch out of "auto" on light switch. Always double lock with remote. Turn of cabin lights or check that the lights have actually turned off.

Salim

mandyfig

Time to make the trip to the dealer.

grouch

Like you and others, I had a similar problem on two different cars.

Turned out that in one car I had turned on one of the rear reading lamps while cleaning it and didn't notice.

The other was a bad ground wire that wasn't tight.

Both resulted in the battery going dead after several days of setting.

markr346

All good suggestions and appreciate the comments and suggestions. We're going to have local dealer (non-Lexus) check to see if there's anything draining the battery when off (an amp meter, I believe, is what the guy said). If they spot something, then we'll drive to the dealer and have it fixed under warranty. If not ... hmmmmm ... I'll get to use my "new" jumper cables again!

salimshah

Ammeter is the right instrument, BUT what is the expected good value? I would say the dealer is most likely the shop who knows what to expect.

Salim

CK6Speed

iTrader: (1)

When the car battery is fully discharge (That is anything below 11V) it is considered completely discharged, and the battery will NEVER again hold 100% capacity. That is why is is very important to never fully discharge a lead acid car battery. Anyway, the battery can still work for years even with 1 or 2 more complete discharges, but each time you completely discharge it, you are taking another chunk out of its max charge. So, if say 12.4V is 100%, the battery may only recharge to 12.0V, and maybe 11.8V on the next full discharge. Only Deep Cycle batteries can withstand complete discharges and be recharged completely.

Anyway, if you drive your car every single day, perhaps the alternator can eventually fully charge your car battery, but it will take a few days or longer. A battery charger is always your best choice.

Another problem the OP may have is a loose battery terminal connection. I've had this happen on a number of cars. My latest was my 99 LS that I just had the battery replaced at Sears. After 2 weeks the car showed signs of a dead battery. Sluggish starts or my dash lights would dim and can't turn the starter at all. Anyway, I knew it couldn't be the battery so I opened the hood and found a ever so slight loose positive battery terminal.

markr346

Our local dealer gave it back to us ... they disconnected the remote start ... thinking it was draining the battery. We're going to let the car sit for a few days and see what happens. They indicated they may have to replace the remote starter (or the "brains" module of the remote starter). Since it was not installed by a Lexus dealer, I'll have to stay with the dealership that did! Again, thanks for your suggestions/posts. (AstroStart is the brand we have installed.)

The G Man

If they diconnect the remote start and saw a drop in amp draw, then thats the problem.

pumaonly

3 times in the last 8 months, my RX has failed to start. Everything and I mean everything is dead. This will happen over night or one time as short as 5 minutes! A quick jump and everything is just fine. 2 dealers have have looked at it and have found absolutely nothing. The last time a dealer had it for 4 days and I was told "everything is within correct parameters". The battery was found weak after the second incident and replaced by Lexus after a short discussion!
For buying a car that is supposed to be reliable, this is one I can't count on.

Any suggestions?

Booyah

Unreal--my RX350 will start after 3-4 weeks in the winter here in Alaska -5 to -25 weeks at a time.....its been done numerous times