Just replaced my 4 year old original battery with an EverStart Maxx. I have been testing/monitoring its condition for the past year or so. Latest report from my tester had health at 63% and charge at 20%. CCA was down around 450, and Cranking score was LOW. I am sure that I could have kept it going longer but I figure 4 years is pretty good and I did not want to get stranded somewhere.

Took about 15 minutes and battery was out of the vehicle for about 3 minutes.

Restarted and everything was working fine except for my Parking Assist was OFF (even though ON was selected in the menu). Drove the vehicle about 1/4 mile and Parking Assist started working again.
So you do not need to have a backup while you replace the battery yourself....just an FYI.

 

Your ahead-of-the-curve maintenance habits and willingness to share are really helpful to the rest of us. Thanks.

It sounds like driver position settings, etc. all survived the battery swap. That's good to know. My battery is also about to have its fourth birthday, and is looking a little crusty. I'll probably go with the same Everstart Maxx. What battery tester do you use?

 

What was BCI group number on your "Everlast Maxx with 750CCA & 925 CA"?

 

I have one of the cheap Topdon units. Seems to do the job. Costs like $30 on Amazon

 

Our vehicles take 24F (and I think others will fit too)

 

The factory battery has a lousy CCA of 500+. While the battery from Costco and Walmart are at a CCA of 700+.

With the low temperature in the winter and the dash cam set to parking mode, it is slow killing the battery.

So my solution is buying a battery maintainer at Harbor Freight for $20. Charging it every night for few days. Now my battery’s health went back up to 98%.

 

I was confused as of which 12V battery you were referring to. It looks like you are using BCI 24F as main starter battery.
In 4th gen RX450h there is a small battery in the back, that is OEM Panasonic D23. I am looking for advice of which BCI type can be used instead.

 

Sorry....I do not have a hybrid. My battery under the hood is BCI 24F

 

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!

 

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).

One possible workaround for keeping the AGM battery in good shape would be to charge it overnight once a week with a smart charger that has the AGM setting. Combine this with a battery test once every six months to confirm all is well. Here is a decent charger on Amazon:

 

For whatever it is worth, 37 months ago we installed an Interstate MTX-24F battery in our 2017 RX350. We typically use the RX for all of our short trips which is usually hard on a battery. Haven't had any issues with it since, knock wood.

 

1.5 years ago, I replaced the battery in my 2015 RX 350F and decided to do this at the Dealer's. It was a standard base baottery at $250 ish and when I got the car back, all my settings & NAV were off. They should have piggy backed the power so none of the settings were lost.

Now in hind sight, I would have gone to an Auto Part stores and have them install a Duralast. Much better battery for the same price.

 

Would they have saved your settings?

 

With the Autoparts store, most likely not, so they are even. But you miss the point. For the same price, you get a much better battery. The battery Lexus put in at $250, is equivalent to a $175 battery at the Autoparts. BUT, to each their own.

 

I have a 2022 RX 450h that is 18 months old. Yesterday, the 12V battery (in the back of the vehicle) was completely dead. I could not unlock the door with either fob or the key as outlined in the owners manual. Question, if the battery is completely dead, will the key open the lock on the door? I could not get it to open with the key. The door had to be opened by the roadside assist person who used tool to actuate the door handle on the inside of the car. Drove to the local Lexus dealer arriving at 5pm and the service person said they would check it out and if bad put in a new one. Test results indicated a "dead cell". Dealer replaced the dead battery under warranty at no cost and I was on my way by 6pm. Both Lexus Enform Roadside Assistance and dealer were very good and responsive.