I didnt say that the algorithm changed in 2025. It was the same in the last 2 years that I have the car. I believe that that is why my previous battery was dead.

 

I was unclear. There was much discussion above about the algorithm being the same until 2025. I didnt mean your comment specifically ronnaldbar.

I was talking about this quote from tammap

 

The patience of Lexus owners astounds me, your car routinely bricks itself yet you don't demand Lexus fix the problem.

 

Sorry for the confusion. There is no change for the charging algorithm for 2025 model year; however, there was a fresh revision of TSB L-SB-0035-24 for the BSSA losts communication that could affect your battery charging system. Unfortunately, it's not a recall!

Keep the TSB handy.

 

Indeed, this behavior is not at all different from other car owners - who routinely allow their -

They'd pay to kill themselves.

 

I have a plain old 22 NX turbo. no battery issues at all. Always starts and runs.

If I was constantly having a dead battery issue as mentioned in previous threads, I'd get rid of that model car.

I always told my wife, if you always want a car to run when you turn the key, get a Lexus.

Not so much now days on some of their models.

Funny, my 17 Corvette always starts no matter how long it sits in my garage...............

Maybe Lexus should contact GM for help.

 

12 V lead battery dies in any car at some time, it's just matter of years, climate and abuse. I had changed countless batteries in other cars.

It's just that when you have starter on 12V, you can notice it got weak before it's fully dead. Unless it's from sudden cold wave.
In hybrid without such starter it may be not obvious. Mine is fine so far, and I got monitor to confirm it.

 

Outside of age/wear, to me it seems extreme heat is the #1 killer of batteries normally. I'm sure you guys in the south buy batteries by the pallet load, but up here in the 51st state where people get faint if it gets past 80F, I have rarely had to replace 12v batteries. In 44 yrs of driving I've only ever had to replace a battery that was less than 5 yrs old once. My '13 Civic (which I gave to my son) had the original battery go at 8 yrs, the replacement (Kirkland) died after a year. My RX hybrid, 14 yr old and still going when traded, my Camry Hybrid, 6 1/2 yrs and still going went traded. My Sienna, 11 yrs old when replaced, replacement still going when I sold it 7 yrs later. My wife's Forester did have a new battery at 5 yrs, daughter's Crosstrek still original battery at 5 yrs, Firebird, 8 yrs old still going when traded, Cavalier 8 yrs old when replaced, sold with replacement still fine a few years later. Had a bunch of other cars that never needed a battery, but those were usually with me 3 to 5 yrs.

It is highly disappointing the NX hybrids are having these issues. My friend with a '23 NXh had his battery changed out too and it didn't help, he just had a trickle charger installed a few weeks ago on my advice. I don't think Lexus actually wants to fix because doing so may likely affect the MPG rating of the car, and no doubt that will trigger lawsuits about diminished performance (they've probably already done a calculation of warranty vs lawyer costs). I suspect it'll get quietly tweaked for the 3rd gen NX.

 

After reading through this thread and the one on the RX forum, it is still unclear to me if this low 12 volt battery happens even when the 450h+ is using the level 1 charger? It is unclear because many of the contributors to the thread have only the hybrid model vs the PHEV. Or is it just when left unconnected for several days (e.g. at the airport while away on vacation) or driving that the 12 volt battery voltage drops?

 

I have used the on both a travel trailer and sailboat house battery and have been happy with the smart phone monitoring that it provides. It is about CA $135. The advantage of this device is that it measures the amps going into and out of the battery rather than just the battery voltage. It would likely be simple to install in the battery compartment of the hybrids. Has anyone else installed this device in their cars?

 

These require shunt to interrupt battery wire. I would be wary to do it on an expensive car still in warranty.
There are others that use less intrusive Hall effect sensors (clamps on existing wire) but reportedly they are inaccurate.

For me it was only to make sure the car charging system works as intended, and as an early warning of nearly dead battery. IMHO it isn't like you would need to monitor remaining capacity as close as for off-grid system.

 

I have been using this for few months now - in a parallel circuit with the stock battery, without altering any function of the stock battery. It effectively creates a redundant system design for the failure-prone 12 V battery subsystem.

 

Could anyone upload a graph from a battery monitoring, showing if the car is charging the battery during a drive?
In my car, the battery is being charged mostly when the car is ideal.

 

Where are you and what is the current weather?

 

The weather is around 19 deg Celsius.
I am in Cyprus.