WWYD - 7y old AGM battery still shows 85% of rated CCA

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Although prices have improved a little since the height of COVID, a Deka replacement for this battery still runs about $550-600 + tax in my market. Winter is coming, and I'm wondering if I *really* need that replacement just yet or if this is one of those cases where a well maintained AGM battery lasts a very long time. Curious WWYD.

Application: BMW F10, dealer warranty replacement battery PN 61212353812, AGM 92AH 850CCA group 49, installed in 2015.

The vehicle overnights in my garage 99% of the time. I have a wall mounted CTEK MXS which gets connected overnight often. The vehicle itself reports that most of its life the battery SoC is >80%, and has never dipped below 60% for any length of time. I do not have an auto start/stop function.

If I top up most of the way with the CTEK, give it a couple of hours and a bit of load to remove surface charge, my Solar BA9 says 12.71V 725-730CCA @ ~70F

Yes, this battery owes me nothing. It's 7 years old. But, $600? Discard something perfectly useful? Because the BA9 is fairly new to me, I don't have readings from when the battery was new. By my math this battery calculates out to a SoH of ~85%. But for all I know it would have read 1000CCA on the BA9 when it was new, making it more like 70% SoH. Assuming the BA9's testing method can really be trusted...

I used the cranking test on the BA9 earlier today as well. If I read it right it stayed above 12V during cranking. I might play with that a little more to be certain. Last November with this battery I performed a maintenance procedure that required oil system priming. It cranked the engine for 60s over a couple of minutes (cool down breaks) with full compression (plugs in, injectors disconnected) and I think it held 11 or better the whole time.
 
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IME AGMs don't fail as suddenly as SLA. I'd still use it. <dogememe> he's probably including BMW labor; I don't know.
 
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I'd use it. I just replaced the original battery in my 2009 BMW 328i a month ago. It still cranked over it was just getting noticeably slower.
 
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that battery is totally fine. especially if you put it on a charger often. whatever you do, don't turn it in for the core charge it's worth way more than that. but yeah $600??? there's walmarts in Toronto you can get one there for 200. or heck even amazon delivered for 250 probably.
 
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that battery is totally fine. especially if you put it on a charger often. whatever you do, don't turn it in for the core charge it's worth way more than that. but yeah $600??? there's walmarts in Toronto you can get one there for 200. or heck even amazon delivered for 250 probably.
Maybe for a flooded battery, but I looked at several Canadian parts store sites, looks like 49/H8 sized AGM batteries are about $500 across the northern border.
 
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I would get it load tested the old fashioned way just to make sure the battery is still good. While I do not distrust your Solar BA-9 conductivity tester, I do think a load test would be in order as a complimentary test.
 
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The DEKA 9A49 AGM is about $254 US including $18 core charge, on Rock Auto. Depending on how close you are to the jobber selling it, the shipping could be rough. Of course, Canada would be a deal breaker I suppose. 30 mo. warranty.
 

Craig in Canada

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Regarding price - that is the cash and carry price for a Deka battery up here, no labour. Core is also $20 vs $5 in the US. It was $800 a year ago. It was high $200s pre-COVID I think. There is something at play other than just the exchange rate to CAD. Non-Deka options are less expensive, but I've also had non-Deka flooded batteries turn into an annual warranty replacement in the past.

I am going to scope out a Walmart to see if I can find East Penn batteries based on serial# but not sure that the stores have AGM H8s at all.

I don't have a lithium jump pack right now but I think I'm putting one on my Christmas list regardless of whether I do this replacement now or not.
 
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$550? What? That’s like a $230 battery at the store I work at.
I was quoted $400.00 and change for a new AGM battery installed in my Jeep, from a local dealer here in town. I bought the best AGM battery at Autozone that was an exact fit, with more CCA and a one year longer warranty for $205.00. They even offered to install it for me.

So if he was quoted $550.00 for a replacement battery from a BMW dealership, that's in the ballpark. They don't call these places "Stealerships" for nothing.
 

Craig in Canada

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So if he was quoted $550.00 for a replacement battery from a BMW dealership, that's in the ballpark. They don't call these places "Stealerships" for nothing.

OK I'll settle this repeat theme on price - this is from NAPA auto Canada, the only place I've been able to find a battery which is East Penn/Deka with 100% certainty. Anywhere else you're taking a guess at which brand is under the store label (Walmart, Canadian Tire etc...). I have contacted every "dealer" and East Penn Canada themselves to look for more places to comparison shop Deka AGM H8 or H9 (my car can use either) without much luck, other than Canadian Tire AGM batteries "might" be Dekas.

The H9 / 95R (which I'd prefer to get over the H8, but not for this price difference) is still $720+core at Napa Canada.
 
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The H9 / 95R (which I'd prefer to get over the H8, but not for this price difference) is still $720+core at Napa Canada.
Is this Deka H9, (or whatever it is), really that fabulous, or have that much better of a warranty, to justify that much more expense? I'm sorry, but personally I'm not seeing a "name brand" battery being worth that much more. ($720.00 + core out of a NAPA store). Even if it did last a bit longer.

It's a battery, not a transmission.
 
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I wouldn't worry about it until I noticed it cranking slower, then I throw my CTEK on it and go from there. I got two more years out of an AAP AGM after the first detected slower crank.
 
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Craig, I can understand your concerns about the age of the battery, especially with winter coming to your area. You have another choice if you dont want to replace the battery and hedge your odds of getting stranded. Get one of these jump boxes and put it in the car. Use it if the battery fails to at least jump start your vehicle to get you home so that you can then replace said battery.

 

JHZR2

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IME AGMs don't fail as suddenly as SLA. I'd still use it. <dogememe> he's probably including BMW labor; I don't know.

I’d tend to agree. And if it was on a less finicky car, say my old E30 that I ran a group 49 Adela AGM in, I’d agree. The issue is that these new BMWs may (emphasis may) be more sensitive.

A group 49 has a lot of oomph for starting a ga$ engine. I’d stick with the existing battery until the electronics in the car start acting finnicky. Or the car cranks slow or shows too low a cranking voltage.

Or else make a road trip to the USA to buy one here.
 
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