My RX 400h eats little batteries...

[Dharlee]

I bought this car in Oct of 21 with about 170ish k miles. I know I don't drive it as much as most people drive hybrids, but I don't *need* to except to drive it enough to keep the big battery going. Anyway, right after I got it I had to out a small battery in it. Then come spring of '22 I had to replace it. I basically have to charge the car to make it start for a few weeks when it gets like this. Now I'm at the same place. I can't just go out the door and start my car. It's got about 174 k miles now. It's big battery has never been replaced. Can needing the big one cause this? No one can figure out what's wrong that it seems to eat batteries. TYIA

[RX400h]

Do you have an Auto Electric shop in town? They are typically experts at finding pesky electrical drains.
When you take the car out, how many miles do you drive? We drive ours for a minimum of 12 to 20 miles. Our small battery, a Costco one, lasts about 5 years.
 

[Lexus-CT]

Our little battery is now 7 year and still no problem, brand unknown, OEM and have never bothered to look as it is still OK. Have only one car so we use it 3 - 7 times a week. 

As far as I can figure most hybrid batteries last 20 years or more, otherwise Lexus would not warranty them for 15 years if having the car serviced with Lexus yearly.

 

[Dharlee]

5 hours ago, RX400h said:

Do you have an Auto Electric shop in town? They are typically experts at finding pesky electrical drains.
When you take the car out, how many miles do you drive? We drive ours for a minimum of 12 to 20 miles. Our small battery, a Costco one, lasts about 5 years.
 

We drive it a couple times a week generally,  sometimes more, usually around the same mikes as you. We don't really have anyone other than the local Toyota dealership that knows much about hybrids. I have...trust issues with the Toyota dealership. I have it at a small local garage now and so far they can't find anything wrong with it. They're checking more thoroughly tomorrow.  I'm just not really surecwhat to do. When this first starts happening it doesn't take much to make it refuse to start. It seems so odd to me though because it will beep to lock or unlock. 

[Dharlee]

Lexus-CT my first one I got when I bought the car 2 years ago was a Toyota , now I *think* it's Advance. I'd have to double check that though. 

[RX400h]

15 hours ago, Dharlee said:

We drive it a couple times a week generally,  sometimes more, usually around the same mikes as you. We don't really have anyone other than the local Toyota dealership that knows much about hybrids. I have...trust issues with the Toyota dealership. I have it at a small local garage now and so far they can't find anything wrong with it. They're checking more thoroughly tomorrow.  I'm just not really surecwhat to do. When this first starts happening it doesn't take much to make it refuse to start. It seems so odd to me though because it will beep to lock or unlock. 

This is a starting issue, so it may have nothing to do your hybrid battery. The big questions are:
Is there a current drain on the 12V battery? That is easy to check.
Where is the drain originating from? That might not be so easy.
Are any of these shops near?
Auto-Electric shops in Virginia - Search (bing.com)

[Dharlee]

Thank you! I will check this out with my son tonight! I'll find out later if they found anything with the wiring. (Hopefully) 

[Lexus-CT]

As far as I understand it, the 12V battery is only starting the computer that will activate the hybrid battery. The hybrid battery will then crank and start the combustion engine.

Hope it is just the 12V battery that is losing power and not starting the computer correct.

If local Lexus/Toyota wants a new customer maybe they will let you have them control the hybrid battery and give one more year warranty on it but that might mean that you will let them service the car.

[Dharlee]

I might yet speak to them. I actually bought this car there. But they sort of...did some things that I personally did not like. I'll leave it there. Thank you both for your replies. They've meant a lot. 

[Dharlee]

Hello, I saw where someone suggested a trickle charger that can sit in my dash window. I saw this and wondered if anyone might have advice on if they think it might work and if so what size? I thought it might be worth a shot until I get more funds together. 

 

Sunway Solar Car Battery Trickle Charger & Maintainer 5W Solar Panel Power 12V Charger kit Portable Waterproof for Automotive RV Marine Boat Truck Motorcycle Trailer Tractor Powersports Snowmobiles https://a.co/d/gznDxgi

[RX400h]

An auto-cycle trickle charger is designed for use when a vehicle will not be started for extended lengths of time. If you are keeping your RX in your garage, the solar panel that is part of the Sunway charger may not be effective unless you place it outside. 

If you can plug in a battery tender in your garage where you keep the RX, this is a very popular choice of tender:

Deltran Battery Tender Plus 12V 1.25A Automatic Battery Charger # 021-0128 G3 799793028536 | eBay

[Dharlee]

I keep it in my driveway, not in a garage. I am elderly and was hoping this might be an easy way to solve my issue. I have had it in three shops. No one sees any wiring problem. The person that suggested a trickle charger also suggested it might be that my fob was being kept too close to the car. It is just inside where it's  parked, so I've moved it. 

I'm starting to wonder if it's not so much a battery problem as it is a starter problem as someone mentioned above.

[Lexus-CT]

Hi Dharlee,

You bought the car October 21 and more or less immediately needed a new 12V battery. Bought the car from Toyota dealer. They should have sold a car with a functioning battery.

Then spring 22 more or less ½ a year and the new battery needed to be replaced. On warranty of course? A new battery should last at least 5 years.

Here Lexus closed their workshop and all service is with Toyota, but we get an almost OK service; not like expected from a luxury brand, but our car is driving fine and no problems, so nothing really, to feel sad about.

A 12V battery should keep charge enough to start the computer even if you do not use it daily, and that is all the little battery need to do, but if very cold at night and hot in day where you live, battery is having a hard life. 2008 car could have electric connectors a bit corroded and thus not delivering the power from the battery to the computer, but an electric shop should have been able to find that kind of error.

If Toyota where you live is a real bad place maybe contact Lexus USA and complain. Toyota own Lexus so they should be giving a decent customers experience.

[Dharlee]

That's actually a good idea. They've been pretty shady here. My son was very upset, but I wanted to just find another place. I think I'll do exactly that. Thank you.