What was the reason for the mechanical key not being able to unlock the door?

 

I am interested in installing an AGM battery in a 2020 RX350. AGM batteries require a slightly higher charging voltage than what is delivered by the stock RX350 alternator (they do "work" with the lower charging voltage, but it is definitely not optimal in terms of the life of the battery and its operation). In some other cars, facing a similar scenario, people have had success with "voltage boosters" that cause stock alternators (by "tricking" the regulator) to produce the desired voltage. There are some products that apparently do that without cutting any wires or any other major changes. Specifically, https://voltageboosterpro.com/ https://voltageboostmods.com/ https://www.mechman.com/voltage-boosting-harnesses/
Unfortunately, the websites do not list the 2020 RX350 as one of the supported cars. The last two list the 2018 RX350, but not the 2020 RX350. I tried to contact all three to ask about 2020 RX350 support. The first two did not respond. The last one responded that the 2020 RX350 is *not* supported. My guess is that the "refresh" in the 2020 model involved a change in the type of plug the booster is supposed to connect to.

Has anybody had success finding a voltage boosting solution for a 4th Gen RX350, especially for a 2020-2022 model?

Thanks!

(NOTE: I posted this previously but it somehow (I have not idea how) ended up on a completely irrelevant unrelated thread. I am posting it again in the hope it will get a response when not part of an irrelevant thread. Apologies to anyone seeing this for the second time.)

 

I have no experience with those voltage boosters and would be uncomfortable using them. I suggest to consider purchasing a compatible replacement battery with a higher CCA.

 

Don't know why the mechanical key would not unlock the door??? Does it require battery voltage to operate? It sez in the owners manual if actuated twice, it will unlock all the doors, that would have to be electrically operated. I think the mechanical key is provided in case the FOB battery is dead and the car 12V battery is still OK?

 

No, the mechanical key should unlock the driver side door even if the 12v and key fob batteries are dead. The other doors won't unlock though if the 12v battery is dead

 

If that mechanical key has never been used, I would speculate that the lock mechanism inside the door has simply gotten sticky from lack of use. Perhaps a shot of WD-40 or similar lubricant into the lock cylinder would be helpful.

 

The last battery installed in our RX was in 2019, so I am beginning my search.
Has anyone installed the Interstate 24F AGM? Costco will ship it to me for $200 with a $15 refund when old battery is returned to the warehouse.
Here's the link to Costco's Interstate site: https://costco.interstatebatteries.com/

 

I’ve used lots of Interstate batteries in other vehicles, with great luck, but not their AGM. However, if there’s an Interstate dealer nearby, I would rather just take my car there and have them do the install (free) and then they’ll take the old battery so no dealing with a “core” charge.

 

The retail price for the Interstate 24F AGM battery is $274.95 so if you can get it for $200 that's a steal. In fact, that would be a great price for any AGM battery.

 

The EverStart Platinum 24F (AGM) is $180 at Walmart, net of core charge. Its 48 month warranty is 12 months longer than the Interstate 24F. I've used EverStarts in the past and just put their AGM in my wife's Pilot. My 2020 RX FLA battery is now 4+ years old and I'll likely replace it with an EverStart AGM. At that price it's hard not to choose the AGM.

 

That is a great price. For some reason Walmart's site is telling me it isn't compatible with 2016 Lexus RX350.

 

If you want to make absolutely sure it will fit just measure your battery. The Walmart 24F measures: 10-3/4" on the longest side x 6-13/16" deep x 9 " high. If the connecting terminals are on the correct side you have a match. The website is not always 100% right. Besides, you can always take it back for a refund or exchange. I think the compatibility issue comes up because the data base is telling the Walmart website that your car did not come with an AGM battery.

 

EverStart Platinum 24F. Look at Walmart reviews to start.

 

I just looked at the battery in the vehicle and it is a Lexus 84 month variety. So 7 years if I get lucky?

 

Thanks for the suggestion to use a lubricant inside the key hole. I squirted in some lube and the key works fine now.. One turn to unlock the drivers door, two turns opens all as the manual sez.