2learn

Hello Crew,
New to this board, and am starting a new thread due to being confused by others that I have read. Lexy was working 2 days ago, today, will not start, there is no green ready light. Car opens, head lights work, when I push the START button, without pressing the brake, it goes to amber, the Lexus Enform/ Navigation turns on (it would not before, when I tried to start Lexy) but, the light behind the ***** on the radio/cd/climate control/ middle console flashes, when I press the START button again, (without pressing the brake) all the indicator/ warning lights come on (Now does this indicate that the 12v battery is the problem or not? This is where I get confused with the threads} I did have the 12v hooked up to a battery charger, the charger indicated that the 12v battery had no power, yet the lights on the dash would work. After the charger stated that the battery was charged, tried to start, no ready light, no start up. Turned off car. 2nd try, push the start button without pressing the brake, the middle console **** lights did not flash, used Carista OBD and Dr. Prius, there was no battery error or engine error messages. Pack Voltage;330.28 Discharging 0.00 amp (that is not normal), State of Charge: 60.37% Blade Voltage: 11.01v, Voltage Diff: 0.16v, Max Charge: 34.84hp, Batt Temp1: 64.07F, Batt Temp 2: 64.75F, Batt Temp3: 68.25F. Internal Resistance, unit:milli-ohm: all at 29, Battery Block voltage, unit:volt: all of them in green ranging from 21.95 - 22.01 (if this info helps) So I am trying to figure if it is the Hybrid battery that finally died, (even thou using Hybrid Automotive battery charging system, to charge the battery) or if it is as simple as the 12v battery, but if it is the 12v battery, needing to be replaced, would I NOT have power for the lights? Am I understanding that correctly? Or if it is something totally different.

Droid13

You didn't mention it explicitly, so I'll start with a somewhat basic suggestion. Have you tried starting with the key fob held up to the start button?

2learn

Yes, no "Ready" showing. I even did the emergency start that is in the manufacture manual, did not start. A little more info, the hybrid is giving off the POA80 for battery error message, since May 2020, a week after I purchased it from a used car dealer (lesson learned on that one). Purchased the Prolong Deluxe System to help it till I can get the hybrid replaced. It would give me gas range of 25mpg, at the start of the week, then tapper down to 21mpg, when it was in the range of 19-18mpg, the Check Hybrid System would pop up and the car would start feeling rough. I would clear it with the Carista, the car would feel smooth again, the Dr. Prius, would show, 2-3 modules not working at times, then at times those same modules are working fine. I would start recognizing the behavior/pattern when the mpg would go down to a point I would plug in the Prolong charger, disconnect the 12v battery and charge it for 24-48 hour, the voltage would be at 356 and the amp would be at 3.49. It did help, but if I charged the hybrid battery and left the 12v connected, it would run rough and the Check the Hybrid System would pop up 1-4 times during the week, what I found is if I disconnect the 12v battery while charging the hybrid battery everything was running good. Last fill up of gas the mpg shot up to 57mpg, never saw that before, drove it the next day everything was fine, then the following day, No Start/No Ready.

Droid13

Ahh, well that's different then. With weak cells, there are two possibilities. The cells are actually weak, or the connectors are in bad shape. The recommended solution is of course to replace the entire battery with a shiny new one from Lexus. Sounds like you are willing to roll up your sleeves though, so if you want to tempt fate and are competent working with high voltage systems, you could try to disassemble the battery and clean or replace the metal connectors. I've heard from other sources that these connectors can get quite corroded and simply replacing them or cleaning them can revive an old battery for a while. The other option besides just replacing the entire battery unit would be to replace the weak cells (which is always an iffy situation mixing old and new battery cells together), or replace all the cells while retaining the rest of the battery components. This would depend on cost and availability I suppose whether they are decent options. I've just done some light research one what might be possible, but mine continues without issue so I haven't needed to get serious about the options.

NickSP

Sorry if missed it but what year is your car? I have a 2010 and the previous owner had this same exact code and Lexus ended up replacing the hybrid battery. You seem to not be in America but the standard warranty I believe is 8 years in the US.
If it's out of warranty then see if you can get a refurbished one or someone to thoroughly check and replace the bad cells. Here in the Los Angeles area there are places selling refurbished ones for 1700. Good luck.

Hayk

iTrader: (1)

Sounds like a weak 12v battery. I observed similar symptoms on our 2010 450h. Try a different jump pack and/or jumper cables directly at the battery connections.

NickSP

Did you get any error codes?

Hayk

iTrader: (1)

No codes from what I recall. However I just noticed the later message about the hybrid system issues from the OP so it could definitely be more than just a 12v battery dying.

tempestv8

How old is the starting battery, i.e. the one under the floor in the rear cargo bay area? Being a cold time of the year, the lower temps may be affecting the battery's usable capacity, especially if it's an old battery.

NickSP

I wish people came back out of courtesy to let us know how it ended. Lol.

shannam

My rx450 is currently in the shop for this problem. They are telling me it’s my fuel pump that needs to be replaced.

2learn

Sorry Nick, that is has taken me this long to reply, I finally was able to fix Lexy and I will share with you my experiences so that others on this board can learn as well. If your Lexus RX450H (my year is a 2010) does not show the "READY" light on but you have all the other symbols come on, it is your big Hybrid Battery that is dead, and your 12v battery is working. If your 12v IS NOT working you would not have all the symbols light up. What I did with my situation is I purchased a Hybrid Battery with NEW GENERATION CELLS from Greentc Auto for $3495.00 and they offer a mobile service for $350.00 for a total of 4115.86 (including CA tax). This battery is a new battery for half the price of the dealership who wanted $5900 for the battery only. I also replaced the 12v battery as well since this is a new car for me and I just wanted everything replaced. I chose the Optima Batteries 8040-218 D35 YellowTop Dual Purpose Battery. As for the Prolong Battery System from Hybrid Automotive down in Southern California for $859.00, my experience is this, I would not waste my money on that system and I would stay clear from them, I would put your $859.00 towards replacing the Hybrid Battery. Yesterday was my first day driving the vehicle and what a difference! I know now that when I am at a car wash and the battery goes down (can not hold a charge) or when I am in reverse and the Check the Hybrid System warning light is on, that indicates that it is time to replace that battery within 3 months. I hope this helps you and if you have any further question I will respond.

NickSP

Thanks a lot for your reply. I felt it must have been the hybrid battery. So you spent close to 5k and decided to keep the car. How much did you buy the car for if you don't mind sharing the price? I too bought a 2010 RXh last year so was interested.
I hope your new set of batteries keep you enjoying the ride for many years to come.
Are you in SoCal?

2learn

Purchased Lexy for $13,200.00 this past May, from a used car business, what I learned from that experience is when the RX450h is at least 10 years old, then you will need to realize that you will be taking on the cost of the hybrid battery and that will be your bargaining card, the car place can either lower the price by 4-6k or that they offer a warranty in writing with wording that indicates "that in the event the hybrid battery should fail within 24months that the company will replace it for the full amount of the parts, installation and towing if needed". So moving forward I am really enjoying the vehicle especially the torque, gas mileage, and roominess, that it has from my 2004 RX330. I live in Northern Cal.

NickSP

So your battery price was paid for by the dealer? That's nice. Yeah owning a hybrid before I knew what to look for. Luckily I found a RX where Lexus had changed the hybrid battery for the previous owner as goodwill. So I too am good to go.