DaBottom30

I own a 2008 GS 350. I went to Lexus back in Jan and had to get work done. This misdiagnosed and said I needed to replace a belt due to squeaking. Turns out the issue was with the alternator. I requested to speak to the service manager and they agreed to not charge me for labor if I paid for the part. Paid about $400. Less than 3 months later, within the past 2 weeks the navi-screen turned off while I was driving. More recently the car shuts off then back on within a matter of seconds. Once it happened on my way home from work on the highway.

This past weekend, I was in a parking lot and it happened again. This time the car barely got to a parking space. It would not turn on. I messed around with the battery and finally the car started. I immediately decided to go home. Issue kept happening, steering wheel locked a few times, etc.

I bring it to Lexus today and was just told I need to replace the battery for $200 then they can go from there. To my knowledge, once a car starts the battery doesn't matter because its not being powered by the alternator. I understand they're in the business of making money but this just feels off.

EDIT - Its an Optima Yellow top battery purchased less than 2 years ago

Any advice would be appreciated.

LeX2K

This is incorrect the car will not run properly with a weak battery, in fact if the battery is bad enough the engine will shut off.
Those batteries are known to be junk, they used to be quality not anymore.

peteharvey

Do you have a multi-meter?
Can buy a cheap one for well under $100.
Switch it to DC Voltage mode with a straight horizontal line.
The ~ shaped line above the V represents AC voltage in home etc.
Apply the red electrode to the positive terminal.
Then apply the black electrode to the negative terminal to get a reading.

First thing in the morning, before starting your engine, check your DC voltage.
It should be about 12 V+.
If it is under 11 V, it will be too low to recharge, then you need a new battery.
If it is under 5 V, it is totally gone.

This test is not 100% fool proof, because after 2-5 years, a battery can have a 12 V reading in the morning, but will not recharge to 100% capacity unlike when it was brand new.
A battery that is 2-5 years old has side reactions as it ages, such that it can no longer charge to 100% capacity.
Normally, Lexus OEM batteries are from Panasonic, and they use "100% pure silver", hence they last up to 5 years, but OEM batteries cost a fortune to replace.
Aftermarket batteries have electrodes that are NOT 100% pure silver, so they generally only last 2 years - many people are surprized that new aftermarket batteries only last 2 years.
Operation in cold weather, and lots of short distance drives will also diminish the overall longevity of the battery.

Then start your engine.
Once your engine is idling, the alternator should be recharging the battery, such that the voltage reading should now be around 14 V+!
If the battery's voltage has not increased to 14 V+, then your alternator is not recharging your battery.
This is an easy test.

From your post, I suspect you need a new battery.
However, also make sure you use a multimeter to test if your alternator is actually recharging.

DaBottom30

I plan to go to the shop tomorrow and take the battery from the car and bring it back to Pep Boys where I purchased it. Battery is less than 2 years old so I should be able to replace it.

ibidu1

iTrader: (1)

Inspect your battery terminals, I once had a similiar situation and it turned out to be a rust corroded battery terminal. I purchased a cheap one from a yaris on ebay (its same as lexus) replaced it and cleaned all the terminals.

You also may have a bad connection somewhere, maybe at the alternator, or at the battery. I would inspect both positive and negative

topnycdog

you can check the cheap way. Start the car, removed positive side from battery. If car shut off. It is the alternator

mspearl95

I've always heard thats not a good idea to do on modern cars.

Trose29

Did you ever ever fix the problem having the same problem