FLOODED vs. ENHANCED FLOODED (EFB) batteries?

My 7 year old Mitsubishi Mirage was literally the cheapest car when I got it and has not given me a single bit of trouble besides needing tires, brakes, and fluid changes.

It still starts like a champ except the 7 year old factory battery cranks the starter noticeably slower than it did just a few months ago. I have been extremely happy with the factory battery for this kind of service. Although considered “maintenance free”, the vent caps unscrew and I have added distilled water up to the full level at least once a year and am sure that is one reason it is still going. I wanted to buy the same battery but they are $500!

I noticed something interesting at the local parts stores. There are the standard flooded and now enhanced flooded batteries. I had already decided against AGM since these have a different charge profile and if your car charges them based on having a standard flooded battery, it shortens the life of an AGM. I planned on getting a flooded but then noticed the EFB. It looks like the EFB is an improvement on an old design and meant for use in cars with start stop since they experience a much greater cycle duty. It was supposed to be a cheaper alternative to AGM but appears to be quite good.

Is there any reason not to go with one of these for only $20 more in cost? It seems everything I have read says they have at least double the life of a traditional flooded battery. My main concern is that the charge profile my car is set for might ruin the battery faster if the EFB battery is better charged differently? Any opinions for/against this or is this new EFB the same as a traditional flooded for charging?

Why not go to that place you hate ( Walmart ) ? They have batteries that fit for a whole price range and their are only a few battery manufactures anyway .

There are three reasons I am not a fan of Wal-Mart for this purchase.

  1. I can get the battery at AutoZone for FREE with credit card rewards points which cannot be done at WM or other parts stores. I was eyeing the Duralast Gold or Platinum if I went EFB.
  2. I went through a real bad run of Wal-Mart batteries although that issue is likely fixed. I swear I couldn’t even get a year out of them and I was buying the gold ones. I had my charging system tested and it was fine. Eventually I got one that lasted the warranty and now I am on an AutoZone one (bought with credit card points) and it has been fine as well.
  3. I am not a fan of WM or their policies on many levels. Why support a company that doesn’t support my values or has a way to squeeze suppliers into selling at a loss or making a lesser-quality product.

That being said, if I was out at midnight and needed a new battery, I would head right to Wal-Mart. Some things such as oil are so much cheaper there as well. Why blow $60 in credit card points when I can just pay $30 at WM? It is the same oil, not a watered down version. Also, I can use the points on several other places like certain home improvement and office supply stores so I don’t have to use them for auto-related stuff. It seems like better bang for the buck to use them on something else, auto related or not, instead of overpriced oil. As much as I don’t like WM, I swallow my pride and most of my oil comes from there.

Also, with supply chain issues, you have to buy something where you can get it and that is often Wal-Mart.

The real question I have now is about the EFB. Is there any downside to installing one of these such as a different charge profile when compared to a regular flooded battery? I understand installing an AGM battery in a car not equipped from the factory requires modification to the charging system or you will quickly ruin these batteries. Is there any issue like this with EFB?

I bought a Duralast Gold for my daughter car last week. I was a bit curious on this as well. The Duralast Platinum used to be AGM and I was thinking of getting one until I saw “Enhanced Flooded”. Looked to me like I’d be paying a surcharge for some marketing hype.

BTW, AGM and apparently Enhanced Flooded all use the exact same chemistry as flooded batteries. The charge profiles should be about the same for all, except the charge profile will change based on a lot of factors such as number of plates, size of the battery etc and I suspect they have a greater effect than flooded vs AGM.

Edit: Well after writing this, I decided to google it. The chemistry is the same, but there are physical differences. Most notable is a monitoring circuit that controls charging through modern (computer controlled) charging systems used on newer cars. So I guess they wouldn’t be of any use on a 55 Chevy.

There are physical differences in the plate construction that allows them to take micro charges from regenerative braking systems and they are designed for vehicles with start/stop systems that tend to kill a conventional battery, AGM batteries are also used in start/stop systems but do not work as well with regenerative braking.

Since my daughters car has neither of these, I think I got the right battery.

Here’s a link for you.

https://www.sciencedirect.com/topics/engineering/enhanced-flooded-battery

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I’m still puzzled by the $500 standard battery.

Thanks. I had found similar information. Also, a friend who works at a parts store got back with me and said no special charger is required for the EFB so should just drop in without problems.

It is interesting how these seem to be a compromise somewhat like synthetic blend oils. They have a lower cost than full synthetics but offer many of the advantages.