3IS Battery Drain (merged threads)
Advanced
Joined: Nov 2018
Posts: 628
Likes: 184
From: OK
had battery replaced twice in my ownership. The second one died quite recently. Now, I am supposedly on a new battery and it is already at 10.8V.
I put it on a trickle charger overnight and it gets to 12.2V. After driving the car it shows maybe about 11.7-11.8V
It is either
- another ****ty battery,
- the alternator is not charging the battery correctly
- there is some parasitic draw in the system.
2015 is350
I put it on a trickle charger overnight and it gets to 12.2V. After driving the car it shows maybe about 11.7-11.8V
It is either
- another ****ty battery,
- the alternator is not charging the battery correctly
- there is some parasitic draw in the system.
2015 is350
Last edited by sunamer; Aug 28, 2022 at 03:19 PM.
9th Gear
Joined: Apr 2022
Posts: 9
Likes: 2
From: California
Bumping this thread because my car has begun to have this issue after a year of ownership.
my car is a 2016 is300 f sport AWD. Purchased the car with 37k miles and now sitting at 70k miles.
About 2 months ago car died, replaced the battery and all was good. Car died again, had the battery checked and it was fine. Took the car to my mechanic who then replaced the alternator as it wasn’t working well and looked to be in need of replacement. Alternator was replaced and in working order, but still the battery was not receiving the proper charge.
I then took the car to a local Lexus dealer. The dealer ran a diagnostic and then told me I needed to have my brand new alternator replaced. I then took the car back to my mechanic who then took video of the alternator showing proper charge.
At this point I’m at a loss. Im so sick of the dealership bull**** and the reality that these cars have a massive electrical issue. I’m not sure what to do or just get rid of it. Shame on Lexus for not addressing this properly.
my car is a 2016 is300 f sport AWD. Purchased the car with 37k miles and now sitting at 70k miles.
About 2 months ago car died, replaced the battery and all was good. Car died again, had the battery checked and it was fine. Took the car to my mechanic who then replaced the alternator as it wasn’t working well and looked to be in need of replacement. Alternator was replaced and in working order, but still the battery was not receiving the proper charge.
I then took the car to a local Lexus dealer. The dealer ran a diagnostic and then told me I needed to have my brand new alternator replaced. I then took the car back to my mechanic who then took video of the alternator showing proper charge.
At this point I’m at a loss. Im so sick of the dealership bull**** and the reality that these cars have a massive electrical issue. I’m not sure what to do or just get rid of it. Shame on Lexus for not addressing this properly.
Advanced
Joined: Nov 2018
Posts: 628
Likes: 184
From: OK
Bumping this thread because my car has begun to have this issue after a year of ownership.
my car is a 2016 is300 f sport AWD. Purchased the car with 37k miles and now sitting at 70k miles.
About 2 months ago car died, replaced the battery and all was good. Car died again, had the battery checked and it was fine. Took the car to my mechanic who then replaced the alternator as it wasn’t working well and looked to be in need of replacement. Alternator was replaced and in working order, but still the battery was not receiving the proper charge.
I then took the car to a local Lexus dealer. The dealer ran a diagnostic and then told me I needed to have my brand new alternator replaced. I then took the car back to my mechanic who then took video of the alternator showing proper charge.
At this point I’m at a loss. Im so sick of the dealership bull**** and the reality that these cars have a massive electrical issue. I’m not sure what to do or just get rid of it. Shame on Lexus for not addressing this properly.
my car is a 2016 is300 f sport AWD. Purchased the car with 37k miles and now sitting at 70k miles.
About 2 months ago car died, replaced the battery and all was good. Car died again, had the battery checked and it was fine. Took the car to my mechanic who then replaced the alternator as it wasn’t working well and looked to be in need of replacement. Alternator was replaced and in working order, but still the battery was not receiving the proper charge.
I then took the car to a local Lexus dealer. The dealer ran a diagnostic and then told me I needed to have my brand new alternator replaced. I then took the car back to my mechanic who then took video of the alternator showing proper charge.
At this point I’m at a loss. Im so sick of the dealership bull**** and the reality that these cars have a massive electrical issue. I’m not sure what to do or just get rid of it. Shame on Lexus for not addressing this properly.
Keeping an eye on the battery. But, I am at 69k miles (2015 is350) and I thought that the alternator was bad, but the lexus tech convinced me that it wasn't. He tested it and it did pass the test. I always count on their greed to upsell me something, instead of not selling me that which I actually would need. 🌝😅
Instructor
Joined: Jan 2016
Posts: 1,180
Likes: 411
From: IL
A bad battery cable is a thing. The forum for my other car has several reports of bad battery cables causing batteries to not fully charge. See if the cable gets hot while the car is running, if so, it has a lot of resistance and blocking the flow of juice to your battery.
A loose connection at either end will reduce your charging function too.
A loose connection at either end will reduce your charging function too.
Driver
Joined: Jun 2019
Posts: 61
Likes: 11
From: Florida
Probably just a defective cell or cell(s) in your battery. Rapidly clicking dash during attempted start is indicative of not enough power to start car (battery issue). While its a bad start on your new ownership, I wouldn't be too worried....however when the dealer replaces your battery and it happens again....THEN start to be concerned.
I have a 2014 IS350 and I experieexperienced my battery going bad for the 2nd time. I have Toyota's Lifetime warranty battery. 1st one replaced at 9 month. This battery has brained out 1 so far. This is a very common problem. It's not the battery. Remember that the IS has 30 plus computers and gateway to maintain the vehicle operations.
Advanced
Joined: Nov 2018
Posts: 628
Likes: 184
From: OK
A bad battery cable is a thing. The forum for my other car has several reports of bad battery cables causing batteries to not fully charge. See if the cable gets hot while the car is running, if so, it has a lot of resistance and blocking the flow of juice to your battery.
A loose connection at either end will reduce your charging function too.
A loose connection at either end will reduce your charging function too.
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Advanced
Joined: Nov 2018
Posts: 628
Likes: 184
From: OK
I am guessing it wasnt the alternator. When my battery needed to be replaced, I suggested to a dealer that maybe it is the alternator.. They are financially incentivized to change more parts to fix my problem, yet they said the alternator was fine. They tested it and it worked just fine. It ended up being a battery clamp which had corroded and wasn't supplying enough juice to the battery.
Yes, clicking sound is a relay clicking on/off as it detects abnormal starting condition.
Yes, clicking sound is a relay clicking on/off as it detects abnormal starting condition.
Driver
Joined: Jun 2019
Posts: 61
Likes: 11
From: Florida
[QUOTE=Bxtaskforc;11601696]I have a 2014 IS350 and I experienced my battery going bad for the 2nd time. I have Toyota's Lifetime warranty battery. 1st one replaced at 9 month. This battery has brained out 1 so far 2nd time. This is a very common problem. It's not the battery. Remember that the IS has 30 plus computers and gateway to maintain the vehicle operations.
Advanced
Joined: Nov 2018
Posts: 628
Likes: 184
From: OK
[QUOTE=Bxtaskforc;11601712]
Sort of yes, correct, but also, since I got my battery replaced with another toyota battery, I had no issues and the car would start in cold after sitting for almost a week in a non-heated garage. Before I also thought that there was an abnormal battery drain, but it is clearly not the case anymore.. So, yes, some batteries being duds is a problem (which is warrantied anyway), but huge parasitic drain isnt that big of a problem.
I have a 2014 IS350 and I experienced my battery going bad for the 2nd time. I have Toyota's Lifetime warranty battery. 1st one replaced at 9 month. This battery has brained out 1 so far 2nd time. This is a very common problem. It's not the battery. Remember that the IS has 30 plus computers and gateway to maintain the vehicle operations.