3IS Battery Drain (merged threads)
Driver School Candidate
Joined: Nov 2013
Posts: 5
Likes: 0
From: california
I did and they came to my office and picked up my car and left me a rental. LOL!
The pursuit of F
Joined: Jul 2006
Posts: 8,296
Likes: 303
From: Toronto, Canada
If there's such a thing as Lexus and unreliability in the same phrase, it will be because of the battery. I've had "weak" OEM batteries with the latest Lexus cars I've had and on each one, the battery died on me once or twice only after about 30 or so minutes of listening to the radio. On one older RX I had, I eventually bought a higher (680 vs 490 amps if I recall) amperage battery at Costco and what a difference - I was able to listen to the radio for longer than 30 minutes without issue.
It's not just Lexus/Toyota. But Honda and others with weak OEM batteries. Some cases have had defective cells. I suspect yours is the case and if so, expect a new battery.
Good luck
It's not just Lexus/Toyota. But Honda and others with weak OEM batteries. Some cases have had defective cells. I suspect yours is the case and if so, expect a new battery.
Good luck
Driver School Candidate
Joined: Nov 2013
Posts: 5
Likes: 0
From: california
If there's such a thing as Lexus and unreliability in the same phrase, it will be because of the battery. I've had "weak" OEM batteries with the latest Lexus cars I've had and on each one, the battery died on me once or twice only after about 30 or so minutes of listening to the radio. On one older RX I had, I eventually bought a higher (680 vs 490 amps if I recall) amperage battery at Costco and what a difference - I was able to listen to the radio for longer than 30 minutes without issue.
It's not just Lexus/Toyota. But Honda and others with weak OEM batteries. Some cases have had defective cells. I suspect yours is the case and if so, expect a new battery.
Good luck
It's not just Lexus/Toyota. But Honda and others with weak OEM batteries. Some cases have had defective cells. I suspect yours is the case and if so, expect a new battery.
Good luck
Driver School Candidate
Joined: Oct 2013
Posts: 19
Likes: 0
From: NE
My Mom has a 2012 Toyota Camry which also had a parasitic battery drain. The battery would be dead after sitting for a week. The dealer told her it was "normal" and that she needed to drive it more often (easy way to appease a 79 year old widow, I guess). I measured the current drain. It was about 350 ma and would fall back to about 250 ma after the car had been quiet for about 20 minutes. After doing some research, I found that quiescent power drain on her car should be less than 50 ma. Armed with that information, I went to the Toyota dealer with her and they looked a little closer. They found a bad ground on the firewall which was not letting the power drain fall back to normal. After they fixed this issue, the quiescent power drain was about 15 ma.
Most car batteries are in the 45 to 60 amp-hour range. Don't confuse battery capacity (amp-hours) with CCA (cold cranking amps). So if you have 500 ma battery drain on a 50 amp-hour battery, that battery will be completely drained in 100 hours. However, long before you get to 100 hours, there will be insufficient energy in the battery to start the car.
If your battery is draining down after only a day, there is a major parasitic drain. Use a digital multimeter to measure the current drain. It is pretty hard for the dealer to argue with numbers.
Most car batteries are in the 45 to 60 amp-hour range. Don't confuse battery capacity (amp-hours) with CCA (cold cranking amps). So if you have 500 ma battery drain on a 50 amp-hour battery, that battery will be completely drained in 100 hours. However, long before you get to 100 hours, there will be insufficient energy in the battery to start the car.
If your battery is draining down after only a day, there is a major parasitic drain. Use a digital multimeter to measure the current drain. It is pretty hard for the dealer to argue with numbers.
Last edited by GaryHE; Nov 18, 2013 at 04:38 PM.
Lexus Test Driver
Joined: Aug 2007
Posts: 1,084
Likes: 2
From: North Carolina
Driver School Candidate
Joined: Nov 2013
Posts: 1
Likes: 0
From: California
I purchased a 2014 Lexus IS 250 Sport back in August and maybe a month later my battery completely died after not driving the car for two days. The dealership said that I must have left something on, but there is just no way. My lights are on automatic, doors were shut, and I would have noticed something since the car is parked in my garage. I took it to the dealership and they found no issues. They went ahead and put in a new battery anyways. Not sure if they were just covering up an actual issue but I definitely appreciated the new battery. Hoping it doesn't happen again!
Driver School Candidate
Joined: Jul 2013
Posts: 25
Likes: 0
From: CA
Just happened to me as well...
I just walked out to get something out of my car and the battery is dead. I remember seeing this post earlier this week, so I figured I would add to it. I have ~4500-4700 miles on it and it's been approx. 55 hours since I drove the car last. Thankfully today is a holiday and I didn't find out when trying to leave for work. Now I just need to jump it and keep it going until Saturday morning. I already have my (free from the dealer) 5000 mile service scheduled for Saturday, so this is one of a few things I will be having them take care of. 
Happy Thanksgiving everyone!
Happy Thanksgiving everyone!
