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It depends on outside air temperature and how long the car sits without running. Normal parasitic draw will pull the battery voltage down a significant amount overnight. I used a fairly accurate oscilloscope to take these voltage readings. My battery and alternator were in good shape and working correctly ignore my speculation in these links. Years later the same battery and alternator are in the car. They work fine. The voltages I took were good normal voltages. Using a load meter or checking your battery with a hydrometer will tell you more accurate info about your battery health but I'm sure your aware of those.
I've measured between
12.46v and 12.6 after sitting overnight.
It depends on outside air temperature and how long the car sits without running. Normal parasitic draw will pull the battery voltage down a significant amount overnight. I used a fairly accurate oscilloscope to take these voltage readings. My battery and alternator were in good shape and working correctly ignore my speculation in these links. Years later the same battery and alternator are in the car. They work fine. The voltages I took were good normal voltages. Using a load meter or checking your battery with a hydrometer will tell you more accurate info about your battery health but I'm sure your aware of those.
I've measured between
12.46v and 12.6 after sitting overnight.
I found what the problem was, it was the passenger feet light that was on, I hadn't noticed it before because it was during the day when I checked. Now, I don't know what is causing this issue, because I checked all the lock sensors and they seem to be fine. So, how do I take the bulb from the feet light, since my smallest Philip can't seem to unscrew the black screw off the bottom interior?
There is a known issue with the door plunger switches shorting out/failing. Several posters have put new ones in and solved the issue. If there is an issue with door plunger, removing the bulb may not eliminate the voltage drain.
Hi guys,
I believe this is the right trend for my problem. Story short, I drive a 2017 GS 350 F sport which I call it "The Beast". Never been happier, only 19k so far, drive like a Beast indeed especially is Spot +, and I have a problem with the battery drawing. Story short, seats in the garage for weeks 2-3 at the time, and lately, after I changed the original battery with a Interstate, is dying in about 2-3 weeks.
I read all the treads but couldn't find my problem, so, I know you guys are super master in finding the problem and I appreciate it.
Going forward, I did a draws test and found the fuse on the motor compartment left side, right under the battery, being faulty. This is a fuse with 3X 40 amps block, green, pics attached. Can any one help to find out what this fuse is servicing, please? Lexus will charge a fortune I assume, but with my skills a can lowering that down....and of course your help.
All tests and the fuse pics are attached.
If you look under the fuse box cover there is a description of the fuses and links there, you just need a battery maintainer/trickle charger for when you leave it sitting for a few weeks.
If you look under the fuse box cover there is a description of the fuses and links there, you just need a battery maintainer/trickle charger for when you leave it sitting for a few weeks.
You're absolutely right, I keep my beloved LS garaged and on a trick charger. The charger is just a $15 Harbor Freight one. I installed it semi-permanently, routed the plug through the front grille, and it just plugs in without even opening the hood.
I've actually been meaning to add the finishing touch, i.e. to paint the plug in some flat black to make it less obvious - but haven't gotten round to that yet...
(One more thing that I'm really not proud of, is one time I forgot about the charger being plugged in, and drove off with the cord still plugged in...fortunately no harm done, except for my ego! But to prevent that from happening again, now right after I plug in the cord for the charger, I grab part of the cord and put it under the right windshield wiper. I do it in a way that the cord is easily visible at a glance, while sitting in the driver's seat...)
No APP required. Simple $5 Multimeter will easily do the job. Starting gets iffy at 12 Volts warm, 12.2 in hte cold.
Previuosly posted info.
Post I wrote earlier. Hope it helps.
In addition to high temperatures killing batteries prematurely, leaving cars sit and letting the battery drain down then recharge, dramatically shortens battery life, no matter what kind it is.
In order to understand how quick this happens on our heavily computerised cars I thought, I would run the test on my 2015 LS460 SWB AWD. I started with a quality Multimeter that has both DC and AC current(AMP) measuring capacity. You put the black lead into the common port, and the Red lead into the 10A port, may also be labelled just AC/DC A on some meter. Having Alligator clips on the end of the probes will make doing this a whole bunch easier.
I shut off the car, put the key FOB in the house in an RFID box, left the doors unlocked, and lifted the hood. My car does not have a hood open warning light so no hood open sensor that needs to be defeated. I disconnected the negative terminal on the battery, clipped the Red Lead to the battery terminal and the black lead to the Negative cable. I then opened and closed the drivers door. Reading popped to 4.8 amps with the interior lights coming on. Closed the drivers door, reading dropped to 2.7 amps and after about 30 seconds started to steadily drop. Within 90 seconds it was down to .7 amp and still dropping. Within three minutes it was reading between .03 and .04 amps, so 30 to 40 Miliamps.
I had read that the FOB being too close would cause the vehicle to wake up so I went in the house and got the FOB. Even right beside the car, not change in .03-.04 AMPs being drawn. Used the FOB to open the trunk, reading popped up to 6 Amps. Closed the Truck with the auto close system using the button on the trunk lid, reading stayed at 5-6 AMPs. As soon as the trunk latched the AMPs dropped to 2.5 and then kept dropping following the same pattern above. I tried a number of different combinations and permutations, including putting the push button start in the run position without stepping on the brake so the car didn't start. Remember, your multimeter is limited to 10 AMPs, if you start the car, or turn on high draw things like Headlights, you will likely pop the fuse that protects the multimeter.
No matter what combinations I tried, the at rest reading dropped back to the 30 to 40 miliamp reading. The only thing I didn't do that I wish I had done, was lock the doors and see if the at rest reading increased with the security system active. Since I park in a secure garage and never lock the car, I didn't think about that till I had it all buttoned up again.
Since the car sits for long periods of time I have attached a NOCO harness to to the battery terminals to make hooking up the trickle charger much easier. This way I can just plug the trickle charger in without having to remove the clips and lift the battery cover each time to attach alligator clips. I have these quick connects on all my vehicles. Even at only 40 Miliamp, a battery will drop below starting voltage in about a month, if it is stored cold it will go flat faster than that. Remember, lead acid batteries do not like to be discharge down to 11 Volts and recharged. They are much happier and last far longer if kept above 12.3 volts and that means a trickle charger is a good idea if you don't drive your car for at least 30 minutes every 3 or 4 days.
Hope this information helps those of you suffering from batteries going flat or dying prematurely.
Multimeters have a lot of different layouts, this is just for illustration.
As a followup, Charged the battery to full, after an hour off the charger, read 12.73. July 2023 OEM Lexus battery. After sitting in the garage un-driven for 8 days, battery now reads 12.45. So the constant drain, even though very small, definitely draws down the battery over time. Battery went from 100% to 80% in 8 days. Still lots of juice to start the car. Left parked with no trickle charger, and assuming an even rate of drain the battery will be down to 50% in another 12 or so days.
At 12 Volts it is still enough to start the car but this is NOT what lead acid batteries like and will materially decrease its service life. If you aren't driving the car regularly your battery will last far longer if you put it on a .75 AMP to 2 AMP smart trickle charger like a Noco. The other option is to disconnect the negative battery during storage, but I find it a lot easier just to leave it on the trickle charger.
You can use the quick connect cable on the jump start terminals as well, they don't have to go on the battery itself. The reason I put them on mine was so I don't have to remove any of the under hood covers or the battery cover to hook up alligator clips each time I wanted to put the trickle charger on. On my LS you can't reach the battery terminals without opening the battery cover by the windshield.
Here is a picture of the LS460 Battery location. The panel with the Yellow sticker has to be removed at min to get alligator clips onto the battery.
Originally Posted by jmcraney
The LS460s are designed to use a flooded cell SLI battery. An AGM battery has a different charging requirement. Will an AGM battery work OK in an LS460? Well sort of.
The amp-hour capacity of a flooded cell battery is determined mostly by the physical size of the battery. Most LS460s use a size 24 battery that typically has an Amp-Hour capacity of 70-85 AH when the battery is new. Some of the LS460s are equipped with a cold weather package and use a size 27 battery which has a higher AH capacity.
Batteries come with several different terminal configurations. Be sure you pick the correct terminal configuration for the LS460.
Flooded cell batteries are considered to be a "candidate for replacement" when their fully charged State-of-Charge is 75% or less. This means that the battery's fully charged AH capacity is 75% of what it was when it was new. Flooded cell batteries typically reach this condition when they have been in service a little over 3 years.
When the SOC of a flooded cell battery is allowed to fall below 50% it often damages the battery and shortens its life.
Flooded cell batteries cost less than AGM batteries and their service life is nearly the same.
The best advice is to replace the battery with a new flooded cell battery soon after its 3rd birthday or when its fully charged SOC goes below 75%. If you do that you should be able to park it for extended periods and count on it reliably starting.
Spot on!!!! This has been repeated on here by me and a few others, many, many times. No idea why folks still want to put an AGM in vehicles not designed for them. Marketing hype is great at selling folks stuff they don't need.
These earlier threads contain quite a bit of useful info.
Unfortunately, I keep my car in NYC, in one of these places under a building with other cars, and paying for the spot. I don't think the owner will agree to let me use his outlet for many reasons, specifically fire hazard.
Anyway, I have to find first the reason why this one year old battery is losing power (most likely a parasite somewhere). The original Panasonic from 2017 was still going fine, last year, so after 6 years, but I decided to change it and stupid me, I got an Interstate from Costco. I don't blame Interstate, maybe there is something with the car. Fortunate for me, never had a problem driving it after 3-4 weeks with the Panasonic one.
Will let you guy know after I'm getting the DC meter and do the parasitic test.
If you left the car parked for three weeks at a time when you had the Panasonic battery and never had a starting issue, you likely have some increased draw. A common known issue is the door frame mounted interior light plunger switches. They develop shorts and can cause such issues. It's been posted here many times. Replacing all four plunger switches is simple and affordable. It's normal for the LS to drain a battery when parked for weeks. We had many posts about this during COVID, when people parked for weeks and months.
Here we are , back with another swing. ACDC c as i promised:
The results for an DC amps of my car,taken on the engine wires from the battery+ and -, and alternator charge at the end
are:
06-12-21, 03:07 AM
Battery voltage
as i promised:
