Walmart or Costco Batteries

[ammolab]

The AGM from Costco on my Grand Caravan, which came with a flooded battery, is 4 years old. I did have to top it off as it started cranking slower than usual when we had a cold snap. We’ll see how long it lasts.

The OEM flooded battery on my 21 Toyota CHR failed last year and was also replaced with a Costco AGM. I expect to get it topped off at some point as well due to Texas heat exposure.

Did I read right?… You are topping off your AGM battery? They are not sealed?

 

[HowAboutThis]

And the consensus on this thread is?

OP, what have you decided?

I'm buying one of each and swapping them out in a proportional manner relative to the results of this posting.

Nah, I'm checking Walmart and waiting for one to be in stock. Then I scratch my head and think, "what good is a warranty if I can't get a replacement" and realize maybe Costco is the better choice even though it's probably the worse choice.

Long story short, I tested the battery again and it's really hovering just below "good" right now. So I'll test once or twice per month and keep checking the Walmart app for batteries in stock. If it drops lower and they don't have one in stock, I'll either go flooded from Walmart or just go to Costco and roll the dice on losing a small amount of money if it fails within 4 years.

I was also looking at Odyssey and X2 wondering if those, even though they're super spendy, would be a better $$$/year average. AI seemed to put the average life vs. price meter on par with cheaper batteries. Pay more up front, but last long enough to make up the difference.

So now I've thoroughly confused myself.

Long story short, I'm selling the car and getting a bus pass

 

[KrisZ]

Did I read right?… You are topping off your AGM battery? They are not sealed?

Sealed is a relative term.

Thread 'AGM Battery electrolyte top off'

Feb 5, 2026

In short, it can be done.

The Costco Interstate AGM battery in my Grand Caravan was getting slow when cranking during our below freezing weather recently. Earlier this year I notice that the resting voltage hovered around 12.6V. Even if I charged it overnight, it would drop to this voltage pretty quickly.
The date code is 07/22, and outside the costco warranty. The battery was never run low and I would charge it overnight from time to time.

The hardest part was getting the caps off. There are not designed to be taken off without some sort of special tool.
My special tool was a chisel...

• KrisZ
• Replies: 11
• Forum: Automotive Electrical

• 
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[vwmaniaman]

I bought the regular Sam's Club Duracell. They are East Penn.

 

[Wheel366]

I'm buying one of each and swapping them out in a proportional manner relative to the results of this posting.

Nah, I'm checking Walmart and waiting for one to be in stock. Then I scratch my head and think, "what good is a warranty if I can't get a replacement" and realize maybe Costco is the better choice even though it's probably the worse choice.

Long story short, I tested the battery again and it's really hovering just below "good" right now. So I'll test once or twice per month and keep checking the Walmart app for batteries in stock. If it drops lower and they don't have one in stock, I'll either go flooded from Walmart or just go to Costco and roll the dice on losing a small amount of money if it fails within 4 years.

I was also looking at Odyssey and X2 wondering if those, even though they're super spendy, would be a better $$$/year average. AI seemed to put the average life vs. price meter on par with cheaper batteries. Pay more up front, but last long enough to make up the difference.

So now I've thoroughly confused myself.

Long story short, I'm selling the car and getting a bus pass

Sign up for Mapa emails. They send out 20% off coupons once in a while. I got both of mine with the discount. Still not as cheap as a Walmart battery but might make the Odyssey easier on the wallet.