jls667

12v batteries only last about 1.5 - 2 years in my rx400h. Is this normal? Since it has always been with this car, I plan for it.

iMSQ

No. Based on my experience - at least 4 years.

Margate330

Only if you are buying Walmart's junky batteries. haha
I bought 4 Deep Cycle Marine batteries from them and they lasted 1-1.5 yrs before not holding a charge anymore.

I run an Interstate brand battery on my car and they run about 5 years down here in South Florida heat.

jls667

Maybe I am doing something wrong. After about 1.5-2 years, I find the battery does not have enough charge to sit for a few days and start the car.

On the starting subject, why does a hybrid car need a separate 12v battery to start the car?

iMSQ

Hybrid battery starts the car/engine. 12v is an auxiliary battery to power all car systems.
PS: Lexus sells 8-years warranty 12-volt batteries (free replacement for the first 2 years, and 50% discount for new battery after that).
PPS: Do you have any after-market gadgets in your car?

jls667

The only after market item is my radio. The battery issue predated the radio.

jls667

I am still having a small battery problem. The 12v battery that starts up the car never lasts more than 2years. Although the problem is not that bad, I would like to attempt to find the culprit. What should the car be drawing from the battery in sleep mode in mA? Do I put my multimeter in between the battery and one of the terminals and just unplug fuses?

Thank you.

LeX2K

Best way is a tool like this

It will not be super accurate but good enough, normal draw should be less than 100 milliamps after a few minutes then drop down to half that 20-30 minutes later.

jls667

Instead I tested the voltage drop across each fuse with my multimeter on MilliVolts to get the MilliAmps of each circuit.

FRDEF 40 MilliAmps
FRFOG 21 MilliAmps
RR DOOR LH 30 MilliAmps
RR DOOR RH 30 MilliAmps

Does this sound plausible?

Leeper

#1- did you fully charge the supposed new batteries? Because a battery is sold as new does not by any stretch man it was fully charged. You can ask them to put them on charge overnight prior to your installing. Your alternator does not fully or properly charge your battery
#2- I'm assuming you're not running a battery maintainer (C-Tek or Battery Tender). Either will bring a decent battery up to 100% and keep it there. They are neither a "battery charger" not a "trickle charger". They usually run @$70-$125USD and are very worthwhile. C-Tek is included with such cars as Ferrari, Bentley and several others

#3- your issue could be parasitic drain, bad alternator, poor ground, or battery connection/battery terminals, driving short distances often

I use a CTek now have used several Battery Tenders on cars and motorcycles in the past highly recommend

dpleticha

I had a battery drain issue on my new 2006 RX400h that turned out to be due to a “device” the dealer installed to provide some kind of premium service that required a subscription from Lexus. I never authorized the service but the device was left in my car until I took the car back to have the battery replaced under warranty and they found the device was draining the 12V battery, I still have to replace the battery every three years but I buy my batteries at Costco and get them prorated without any questions. That worked great until the price of their batteries jumped the last time I did that and I had to pay the difference!

XRX

Try to drive with headlights and air conditioning in AUTO mode.

dpleticha

FYI - https://support.lexus.com/s/article/...-coverag-10506

joedaddy1

iTrader: (1)

my last 3 batteries on this car seems to be on the 3-year plan. exactly. In fact, they all failed on month 37 or 38, which meant the 36 month warranty at costco was null.
I buy the $100 Interstate battery at Costco. California car, normal drive cycle car. I would've added a bigger battery if it helps/fits.

jls667

When I connect my multimeter between the negative wire and the negative side of the battery, I get an average of 52milliAmps after about 15 minutes. That should be great. I guess that I will stay stumped as to why my 12volt battery never lasts more than two years. I too buy my car batteries at Costco, so many of my batteries have been under warranty.