AGM batteries are better. They deliver more consistent power during their lifespan as long as they are being properly charged, and they should last longer in most applications. The two AGM batteries I have installed (one in the trunk of the Jaguar XK8, one in the engine bay of the Subaru Outback 3.6R) perform much better than the regular lead-acid batteries they replaced ever did. As I have stated before, if you can find a good deal on an AGM battery it is a better choice for a vehicle that you plan to keep for years to come.

 

After a week of trying to get a definitive answer to the AGM vs Traditional battery mystery for my 2013 RX350, I bought the Everstart Maxx traditional lead acid battery from Walmart.
For $98 installed (including my core trade in) and a 3 yr replacement warranty (yep I considered the Walmart warranty hassle) it was a no brainer. There seems to be mass confusion about "registering" a new battery", so I made the decision to go back to basics. I even checked with an Interstate distributor who had no clue.
Many of the places that I called about buying an AGM battery )Pep Boys, Batteries Plus, Advanced and a small Toyota shop) either refused to warranty it or even install one, unless the dealer did the registration. Unfortunately my own OBD2 tool is older and doesn't have that function. TBH. at my age, I had no intention of doing it myself anyway. Lifting 45lbs at that angle would not have been fun for my back, and Wally World is only a few miles from home.

I really hated to part with the "Lexus branded" battery that had been in it for 5 yrs, but I am the proactive type and my car sits in the garage for extended periods. I do go out and start it from time to time to keep the seals lubricated.
I will say that the service was impressive and the mechanic was very thorough. He put on a battery tender before I even asked, and thus none of my memory items were disturbed.
However I did notice that the Nav system rebooted itself but with no memory loss, so there must have been some sort of interruption.
Note: The new one has an April 2021 (this month) sticker on it, but the voltage only registered 12.6 volts so it went right on the slow charger in the garage.

 

Thanks for the update. I think you made the right choice, because why complicate things. In five years you may just get another Walmart battery. I like to spend money on premium stuff, I usually fly business class for example, but I just don't understand the appeal of the AGM batteries.

 

That is because you have never owned one. I felt the same way you did until I installed one in my wife's 2006 Jaguar XK8 back in July 2018. It blew away the performance of the previous wet-cell battery, even when the previous wet-cell battery was new. Same thing happened when I installed an AGM battery in my 2013 Subaru Outback 3.6R in August 2019.

 

I was interested in AGM since my RX can sit for extended periods. (also added a permanent battery tender for about $20 so the extended no use periods should not be an issue)
I was not looking at AGMs for any increased performance, and saw no real advantage for me. I can buy 2 of the High CCA Walmart batteries for the cost of a single AGM battery so no thanks for that. I live in the High Sierra country of Nevada where winters can be very cold and the summers will reach temps over 100d F.
Note: Walmart's AGM was $159 but they were sold out anyway.

The clincher was that the places mentioned above would either not warrant the AGMs, or not sell them, unless the Lexus stealership did the "new battery registration". This is the same dealer that recently quoted $300 to replace the front hood struts..a job that cost me $25 in parts and 5 minutes of my time (after watching a U-tube video).

I don't have any high draw after market accessories, but my RX is fully loaded from the factory. The old "Lexus Branded" battery had 650 CCA I imagine that it could have gone an additional 6 months with no problem) and performed admirably for almost 5 yrs. (the new one has 750 CCA)
Absolutely no complaints with that. Even after 5 yrs, everything was preforming as needed..Power windows, sunroof etc all worked like the car was new.
TBH, I saw no difference in any power accessory's performance even with the new battery.

 

What do you mean by "It blew away the performance of the previous wet-cell battery"
What did it do exactly?
My Walmart battery starts my car in the winter and in the summer. Last week I accidentally left my off road lights on while at work for 8.5 hours, and the car still started fine and even cranked as fast as usual. What other battery "performance" is there?

 

Quicker starts in all weather conditions, especially when the temperature is in the single digits. Faster and smoother operation of the onboard electric motors, especially the windows and the HVAC blower fans. Today's vehicles are essentially rolling computers. They perform much better with consistently powerful batteries installed, especially the vehicles that tend to throw spurious codes once a battery begins to weaken. My wife's 2006 XK8 has been known to go through a decent wet-cell battery in just two years. As I have stated before, the key is to find an AGM battery sale and perhaps also combine that with a coupon or gift card. That is what I did for the AGM battery in my 2013 Outback 3.6R. It came with a full 4-year warranty but I will not be surprised if it lasts 8 to 10 years with proper care (which means drive the vehicle regularly and do not let it sit around for more than a few days).

 

This doesn't convince me, maybe because I never owned a trouble-prone car like a Jaguar. As an engineer, the smoother motor operation I consider just a placebo.
I know it works for you, and you're getting a benefit from the extra expense. That's all that matters.

 

The XK8 has over 122,000 miles, has been a blast during our 9.5 years of ownership, and is not "trouble-prone", it just needs more understanding and attention than our three other vehicles do. If you are happy with wet-cell batteries (as I formerly was), then by all means keep running them.

You are wrong about the placebo effect, though. My Outback 3.6R's windows now open and close in half the time they did with the factory battery. I was stunned when I first experienced that little improvement.

 

Do you mean the windows run better with the engine off? Just on battery power?

 

Engine on or off, it makes no difference, the windows open and close in half the time. The HVAC blower system is also more powerful, which means it cools off the cabin faster during the summer months and heats up the cabin faster during the winter months. I was skeptical too, but AGM ownership has taught me that they are worth the money as long as you can find a deal and you plan to keep the vehicle for a long time (which we do with all of our vehicles).

 

You use the AGM batteries and I don't, so you know more about the technology than I do.

I actually don't want my windows to run any faster, or any other electric motor to run faster. In fact, I never run my AC blower full blast, because it's too noisy for me. I'm happy with my crappy battery, as long as my car starts every time.

 

I wouldn't want the electric motors in my 2013 RX to run any faster than they were designed to. Since the OE battery in 2013 was a plain old wet cell, the engineers at Toyota/Lexus must have designed their systems to function properly with that power source.
My old "Lexus branded " battery started my car in -10d F temperatures with no trouble. Sure the cranking was a little slower than in warmer weather, but there was hardly any extra cranking time.

I never said that AGM batteries were bad..Just that for my use, they represented an unnecessary expense. TBH, had I not gotten such a run around from the local battery shops (about the dealer reset thing), I might have decided otherwise. In any case I am quite satisfied with my purchase (so far) and the price that I paid for it.

 

Actually he doesn't. I put an AGM battery in my 2015 when the OEM died and I see no difference in "performance" He has no idea what he is talking about. I guarantee that the windows do not go up and down any faster with an AGM vs wet cell. I did it only because they are expected to last longer. We will see. The car starts the same and all other functions work just as they were designed to. It would not be good for a battery to be able to run the motors in the car faster than designed. And yes, I have a degree in engineering from of all places North Carolina State in the city he lives. Some of it in electrical engineering.

 

Sorry pal, but I full well know how quickly my Outback 3.6R windows operate today vs. how quickly they operated prior to the AGM battery installation. As I stated before, I was stunned at the difference the first time I experienced it. The only change to the vehicle to cause that to occur was the new AGM battery. By the way, I am also an NCSU graduate, both Bachelors and Masters degrees.