sderman

Returning from a 3.5 week vacation I encountered a strange thing for both our garaged 2014 ES350 and our 2017 RX350. Both started fine, but for both cars the screen had a message that basically said that it was doing a reload. All was fine when this was completed (about 10-15 seconds) but a few minor settings had to be manually reset. Very strange. Has anyone heard of this? And why did it happen?

lesz

My guess would be that, if the car wasn't driven for 3 1/2 weeks, its battery charge level was, by the end of that time, at a well below a fully charged level, and I suspect that, when the battery's charge level falls below some threshold level, the car's computer is programmed to stop using the battery's remaining charge to keep non-essential data. Thus, if it dumped that data, it would have had to re-load it when you did start the car after that 3 1/2 weeks of inactivity.

sderman

Thanks Lesz, I kinda figured that. But it's surprising how large the parasitic drain is. And on both vehicles. I've never experienced this on prior Lexus vehicles and my history goes back to 1999 on the ES and 2001 on the RX.

Do you think deep discharges will impact the lifetime of both batteries?

lesz

My guess would be that the extent of the discharge would not likely have been close to what it would have had to have been to cause long-term damage to the battery.

For future reference, though, I would suggest that, if you know that the car isn't going to be driven for a couple of weeks or more, it would be a good idea to hook the battery up to a Battery Tender. The least expensive Battery Tender product, the Battery Tender Junior, can be bought for somewhere between $25 and $30, and it will keep the battery fully charged without trying to overcharge it.

TechNut

lesz

I don't drive my ES during the winter. When the roads are treated with salt for the first time of the winter season, the car goes into the garage and doesn't come back out until the spring. When I do start to store the car, I do hook it up to a battery tender, and, when I have taken it out again in March, it has not done any re-sets of the infotainment system or anything else.

sderman

Minor stuff. On the RX it turned off my panoramic view camera which I had set to auto-display when the RX dropped below a certain speed. On the ES, I had to press the ceiling door light switch so the light would again turn on when the doors were opened. I also had to change the ES's GPS map to my preferred position of always driving upwards on the map.

sderman

I already have a Battery Tender. Just didn't think I'd need it on a modern day Lexus (and mine were garaged and in cool weather). My 99 Vette had an awful parasitic drain. The battery would go nearly dead in 2 weeks. The original DELCO literally died 2 weeks after it's warranty. Bought an Optima deep discharge battery and kept the Battery Tender on the car when not used. The Optima Battery actually lasted 15 years! Sold the Vette last year but kept the Battery Tender which I connect to the battery leads whenever I replace a battery to maintain the settings.

lesz

I could be missing something in my thinking, but I would have thought that there would be more concern about leaving modern cars, with all of their electronics, for an extended period of time without being driven than there would have been with cars a few decades ago, when "high tech" meant having an AM-FM radio.

sderman

By modern-day, I'm just thinking that it should not require much power to store settings on a chip or two (a AA can do that). But far more power gobbling is going on to drain a storage battery in 3.5 weeks. Lexus, by using 0 weight oil to increase their mileage figures, has also decreased the size of the batteries since it's easier to turn the engine over with thinner oil. This saves weight which marginally increases mileages figures but this also means our batteries are draining faster. I replaced my ES battery a year ago. I only got 3.25 years out of it when it failed (from overnight storage in my garage) whereas in the past I got 5-6 year out of Lexus batteries (and replaced them before they failed). I replaced the ES battery with an Interstate MTP-24F from a local tire/battery shop whose specs shower greater power than the same version available from Costco. My 2 cars were in my garage but if they were outside on a cold winter day I wonder if either of them would have started. I wish Lexus would address this drainage problem. We buy Lexuses for their reliability, but having owners stranded after a few weeks of standing is pretty atrocious.

EJC

I keep my cars on a Deltran when not being used.
The system will still go to sleep and reboot after about 2 weeks of non-use.
No big deal