onexcite

They should have give you a new Panasonic battery, they are Japan built and last forever and way too expensive.

It sound like you have some power leaking and make the battery dead. The battery need to be charged at least 60% or more otherwise it will sulfate and losing charge capacity.

The voltage reading will show correctly if battery sit for 12 hours after charged so at 12.65V your new battery seem fully charged. A drawing test will show what going with your car. Keep us posted.

ECL

I will be out of town with the GS garaged twice this summer, each time for about a month. We'll see what happens. I have left it I undriven for as much as two weeks in the past without a problem. Turning off the auto-headlights seems like a good idea.

2013GS

I've been trying to keep track of everyone on this forum that has had a dead battery on their 2013 GS 350 and you are #17 by my count. I certainly hope they solve this issue soon.

jtrue28

Well, in order to really isolate the issue, there needs to be some sort of tracking of who has had battery issues and what they have installed aftermarket; that would cause potential battery drain, if installed incorrectly.

ie: Radar detectors, F-Sport fog lights, etc. The DC power outlets are shut off when the car is off, so I don't see any draw there. Headlights turn off automatically after the car is turned off...so not really following why that would matter.

jtrue28

Also, is there no where to see in our car that the battery is charging correctly? All I saw mentioned in the manual is there will be a battery light that comes on when there is something wrong.

Even the basic POS car has the little gauge saying it's charging at 12.5V...or whatever in the hell it's supposed to charge at.

SW17LS

Obviously they don't last forever or this thread wouldn't be here...

Lots of cars don't have battery gauges...

onexcite

The problem might not be the battery, if the current leaking or alternator fail to charge the battery properly will degrade the battery capacity and failed to hold charge premature. The fully charge Panasonic battery on my GS will read at 12.8 to 12.9v. I once let it drain down to 11.8v or 10% by leave my dashcam on for 7-10 days (300mA drawing) and the car still startable (ambient temp around 50). For people in south region (hot weather), the discharge/leaking current will be more and the engine may not start even at 12v or 25% measure. So right now I think Lexus will try to blame it on bad battery while investigating to the main problem.

http://www.ehow.com/how_7213127_char...y-voltage.html

There also similar problem constant battery dead on 2011 Sienna from various owners. Toyota issued TSB almost 2 years later to address the problem due to failed to release of AC compressor clutch. Seem like similar things for 4GS's owners.

http://www.siennachat.com/forum/89-g...ion-relay.html

BigAnthony

I am no expert but I agree completely. I believe that there is some circuitry integrated that prevents the battery from discharging after 15 minutes so the problem being the alternator or some other aspect of the charging system seems highly probable.

yardie876

My bet is the ambient light sensor and/or the keyless entry system using an excessive amount of power.

williakz

Need to get FLYCT in on this thread. He's the battery pro.

SW17LS

I'm sure its not, especially since people are seeing repeated failures even after battery replacement, and the dealer battery is a different battery from the factory battery.

mso4

iTrader: (1)

I really don't think Panasonic battery are that much better. They all use similar technology. As long as it reads 12.6-12.9V then I'm happy.

Last night after coming back from a 2 hr drive from LA my replacement battery showed 12.9V. This morning after 10 hours sitting it read 12.8V. Yesterday morning it read 12.65V after 12 hr sitting. The only thing different is that I disconnected the radar detector as well as putting the key fob farther away from the car than before. Previously the key fob was located inside a hallway about 8ft from the car.

Thanks I'm glad you're keeping a count. I wasn't aware that many people had problems. Will keep you updated.

I highly doubt the radar detector since I've had it on all my cars for the last 10 years (6-7 cars) or my fog lights and I'm slightly suspicious of the key fob given the morning after voltage reading of 12.8 today vs 12.65 yesterday. So tonight I'll reconnect everything and continue to leave the fob very far away to see any difference. And this weekend I'll try the drain test.

430SILVER

I've only had my 2004 SC430 a few weeks and the battery was dead today, a day the sun finally came out.

I called the dealer and he suggested a battery tender to keep it charged while it's just sitting and not being driven every day. He also suggested to lock the car even though it's in the garage. There are so many computers in our cars they keep drawing current even when the car is not running. By locking the doors it shuts down many components that would be drawing power otherwise.

It make sense to me, so that's what I'm going to do until the battery is fully charged. Then I'm taking it in to have the battery checked just to be sure it's ok.

jtrue28

Yeah, I always lock my car, even in the garage. I find it easier to turn the lights off that way. I set my headlights to auto and when I pull into the garage they always come on. So when I get out, I push the lock button on my fob twice.

MichaelPea

I wonder if this could be related to several posts describing something running after the engine is shut off. I discussed it with my SA and he explained that it's the vapor check on the fuel system. If, however, the tank is less full (more vapors) could it be running more often or longer?