PeteFuller

Harold57

Welcome to the forum Pete.

Several things to check:

• Does it have LuxLink? Units with LuxLink do have a higher current drain at rest.
• Is it possible a door or the trunk is ajar, leaving the lights on? (You can change out your incandescent bulbs with LEDs and it will last much longer. But you definitely need to get to the bottom of why the lights are on, if that is the case.) If so, it could be a misaligned door or trunk lid, bad door switches, etc.
• Do you leave the headlight switch on? That seems to cause extra drain.

Those are a few things to start looking at.

VVTiBob

PeteFuller

Thank you. Now that I know I am not alone I will put it on tender.

GmanSC

mandyfig

Same for me, I purchased the Die Hard battery tender. I plug in the SC every couple of days. On extended periods (more than 3 weeks), I can see the charge dip to 60%. Nowadays, I plug it in every other week and it shows 75 to 80%.

nomods4me

I'm really glad that there are guys like you that continue to own these cars and let them sit in garages. When I have to replace my worn out SC I'll still be able to find low mileage replacements

oldbenz1

My recently-purchased '07 SC430 also seems to have battery drain problems. I bought it last fall and stored it thru winter. I would start it every week or so during winter to circulate the engine oil. It has a less than 2 year old very expensive battery which was usually very weak or dead when when I tried to start the car necessitating a boost, despite my use of a trickle charger that was connected full time. I was told that a "smart" battery tender was required for my gel-cell battery so I bought one and it seemed to keep the battery at full or near-full charge thruout the winter. Problem solved, or so I thought. Now that spring is here, I got the car out of storage but only drive it on dry roads and blue sky days. Today, after 4 days at rest, once again the battery was too weak to crank the engine. A friend had an RX350 that had the same problem- battery would go dead after a few days at rest. He spent many dollars and hours at Lexus dealership and independent repair shops but no one could find any apparent problems. He finally sold the car out of frustration. So here are my questions: do I have to accept this as normal for my car, is this a problem that is common to the Lexus brand, or is there a fix that someone has discovered? I otherwise love the car, but this is of concern and reduces my confidence to drive the car without worry.

njsteve

Not sure what you have
Installed a Diehard battery Feb 1 been using a Genius tender since
Never an issue always in green

GmanSC

I used to have same problem with old battery. Bought the new Interstate battery at Costco, keep on the battery tender, so far had no problem for last two years.

oldbenz1

Drove my '07 SC430 yesterday but again today the battery was too depleted to crank the engine. In fairness, when I went to drive it yesterday I found it with a dead battery after only 4 days at rest and simply gave it a boost just enough to start the engine. I then drove it about 25 miles. Maybe this was not enough to give it a full charge? Repeating my earlier post, battery is less than 2 years old and tests OK. If I interpret correctly what other forum members say, it seems this is a price we must pay to drive our Lexus (others with this problem seem resigned to always connecting a battery tender if they expect several days of non-use). I find this unacceptable and if wonder if anyone has confronted Lexus, Inc. with what seems to be a design problem.

Harold57

If you have a multimeter, you can check to see how much parasitic current is being drawn from the battery while sitting off. You'll have to put the ammeter in series with the power cable to do that though and then wait for the initial start up (of the electronics). If the draw is larger than 20 or 100 mA, then you've got a problem component somewhere that you'll have to narrow down probably by pulling fuses one at a time.

I'd suggest the following:

• If you use the automatic headlight setting (so the headlights turn on when needed), turn it off and go manual.
• Make sure that all interior lights are off, including the trunk lights.
• Replace all interior lights with LEDs
• Do you have any electronic aftermarket items installed in the car? Try disconnecting them.
• It seems like there was an issue with the security system at one time but I don't remember the specifics.

DJWLDW

oldbenz1

I have a Duracell Platinum 48 H6 AGM battery in our 2006 SC that was made in Jan 18 and installed in Feb 18 purchased at Sam's Club. They are around $160 and our SC sat this winter for several weeks at a time when the weather here in AR was not good and I have never had a problem with it cranking right up. I think yours is a system or component issue. Now I do not leave the Headlights on Auto and I always turn off the radio before turning the SC off.

Dennis

HIDsightz

I had this issue myself in my 2002 and it ended up being the alternator not generating enough power due to wear and tear and also was soaked from a leaking power steering line.

kimmer1

running this car 09 es350 only for winter here in minnesota is a tender the answer? as some would say, or is starting and running it ok. seems fine ..now!