And are ****.

 

Well, that's interesting. My 2016 CTS DD still has the OEM in it. When my 2016 C7 went away a year ago it still had the OEM. My 911 had the OEM for eight years before I changed it last year. My 2003 Avey is on it's third battery in 21 years, so seven years per battery. None of my vehicles sit outside but I can't figure how sitting out would affect battery life. No battery is exposed to direct sun light and the ambient is the same in or out unless you have an A/C'd garage, most do not. Everyone's experience is different....we live in the same city.

 

Here in AZ you are lucky to get more than 2 years on a battery. After living in IL, I have learned heat is tougher on batteries than cold.

 

I ran the original delco battery in my 2015 C7 for 7 years without any problem, not even a burp. Thought I might be pushing it so I broke down and replaced it. Always been a big fan of Interstate batteries so that is what I installed and it was in the car when I traded it in on my C8.
Batteries can be hit or miss but it sounds like you are taking care of yours and I agree with whoever said 5 years was a good spot to consider a new one.

 

I am sorry to hear that. I have always lived in Phoenix and have only one battery that didn't last 2 years and that was in my wife's car that has Start/Stop. Matter of fact 2 battery's in it that didn't.

 

I've been stranded more than once due to a dead battery in my decades of driving. When I lived in FL I would replace them at 3 years no matter what. I live in NC now and my daily driver Nissan is on its original battery at 5 years. Every oil change I say I want the battery replaced and my service tech tests it. He said last time I should bronze this factory battery when it dies, but he said it's testing better than specs. I do put it on a battery tender now and then as there are times I don't drive either car for a few days.
Not a big expense if you want it replaced proactively and I get that concept.

 

I have been using a 5 year replacement schedule even if no sign of trouble is evident. I just figure at that point the life span of the battery is limited.

 

Good choice! The AntiGravidty Lithium-ion battery is second to none. I have had this battery in my C8 for 3 years now. It is the 14.5 lb H6 Group 48 that has 40 Ah or 1500 Cold Cranking Amps. The stock C8 Cold Cranking Amps battery is 770 Amps. This H6 Group 48 model has a weight savings of 32lbs over the stock C8 lead acid battery.

According to Antigravity the battery without any maintenance will last 7 to 9 years. I have now owned this battery for 3 years and 4 weeks ago charged mine for the first time. With occasional charging maintenance from the $122.00 CTEK Lithium 12 volt 4.3A LiFePO4 US Smart Charger, "connect and forget", (Do Not use a normal lead acid trickler on a Lithium-ion battery) the H6 Group 48 battery according to CTEK will last up to 3 times longer. Best time to charge occasionally is during the summers months especially if you live where it's hot.

This is the perfect battery for me since I have no plans on selling my C8 anytime soon. Change my mind I'll switch it out with a lead battery.

Also worth noting is this line of batteries offers a built-in Re-Start WIRELESS Remote Jump Start to never be stranded. The remote is the size of a small key FOB.

 

goog video on advantages of AGM batteries:

 

[QUOTE=RKCRLR;1607676498]Technically, AGM batteries have a different optimum charging profile than FLA. In practice it doesn't seem to

Mostly Incorrect. FLA and AGM are the same (lead acid) except that the AGM has the acid electrolyte in a fiberglass mat - somewhat solid. They have the same charging parameters- within a 0.1 Vdc.

Lithium is 1 gazillion % different.

 

What's mostly incorrect? You seem to have garbled the quote - I think the quote was mostly correct. Folks toss that term "charging profile" around a good bit. There are couple of things about AFM batteries - perhaps mentioned in this thread. One is that the state of charge vs resting voltage is different, so a system that uses resting voltage to estimated the state of charge will get a slightly different (if negligible) estimate of the SOC - if the system is assuming FLA. The other thing folks have noted is that the internal resistance of an AGM batter is lower. And, yes, it is lower. That might mean a higher charging current for a given charging voltage, but depends on not only the internal resistance of the battery but also the internal voltage as well, so its not all that simple to just claim a higher current. The current flow is determined by

I (charging current) = (V charging voltage - V internal battery voltage)/R (nternal battery resistance).

Regardless, I'm sure there are differences, and it might be possible to create a different variation in the charging current vs time/charging voltage for the AGM vs the FLA that is in some sense "technically optimal" But in practice folks drop an AGM in place of an FLA all the time and make no mods to their charging system and have no issues. So as a practical matter it does not matter. Pretty much what the statement said.

LI batteries are very different - but the Anti-Grav battery brand is designed to drop right into 12 volt system designed for an FLA battery - and that information is on their website. Its been confirmed by forum members as well. The reason that works is because the AG battery has a built in battery management system. Even so, their site also indicates that for external charging, an LI specific charger is needed. Other LI brands may differ. The point is just you have to look at the specific battery and what the maker says about its applications. You can't just generalize on the basis of the known chemistry and associated characteristics without considering the role of the built in battery management system.

 

[QUOTE=C8J;1608722687]"They have a different charging profile compared to flooded batteries".
"The bulk charge voltage of a 12V flooded lead-acid battery is typically 14.2 volts." "The float charge voltage is typically 13.4 volts."
"The bulk charge voltage of a 12V AGM lead acid battery is typically 14.7 volts, and the float charge is typically 13.8 volts."
https://www.power-sonic.com/blog/flo...e-differences/

 

@RKCRLR I fixed post 31. The automatic quote function made it look like both statements I quoted were yours. Its repaired now to properly identify each quote. Sorry. I was saying that I agree with your statement.

 

Like Politics, One can quote various sources, but taken out of context it is meaningless. Three major factors when charging are TEMPERATURE, Battery SOC, Battery Condition (not just age, but how used and charged).

You can go to Lifelinebatteries.com (#1 manufacturer of AGM batteries on the planet) and read their technical information.
At std temps & 100% new, Fully charged is 13.2 Vdc.(Guaranteed 2.17Vdc per cell, 6 total for "12" volt battery - 13.02, but usually 2.2 Vdc - 13.2)

Everything is based on that - Plus 1.0 Vdc, minus 1.0 Vdc
Starting from 100% SOC, when battery reduces to max of 1.0 Vdc discharge down (at rest) start Charging.
When charging starts, turn off after battery reaches 14.2 (1.0 Vdc above 100% charged voltage) with little or no current draw.
This yields Discharged battery (time to charge) 12.2 Vdc, Absorption 14.2 Vdc, Float 13.2Vdc.
It is that simple and straightforward.
Depending on manufacturer, these values may vary because not everyone uses high quality materials (some only have 2.1Vdc or less per cell) in their manufacturing like Lifeline/Concorde!

As mentioned ad-nauseum, GMC doesn't follow correct charging (on the C8) on any level!

 

Lifeline.com appears to be about healthcare and senior living. Did you mean
lhttps://lifelinebatteries.com/

 

yes

 

Every source I've seen says that AGM batteries require a different charging profile than FLA batteries for optimal charging.

Since Lifeline doesn't appear to make FLA batteries (they seem to target RV and other specialized applications and don't even make regular automotive batteries) they don't compare FLA and AGM charging profiles that I can find. However, even Lifeline says this:
"The first thing you need to get your AGM battery to full health is an AGM compliant charger. Many chargers will say on the label whether or not they can be used with AGM batteries."

And Battery University says this:
"Choose the appropriate charge program for flooded, gel and AGM batteries. Check manufacturer’s specifications on recommended voltage thresholds."
https://batteryuniversity.com/articl...ging-lead-acid

 

I thought your original statement was correct - they have a different optimum charging profile but in practice it does not matter. I think the key word is "optimal" and what that means.

I was not sure constitutes a complete definition of a profile. But on that Lifelinebatteries.com there is a technical manual, and in that technical manual appears a section called "Charging". And in that section is lengthy discussion of charging - discussing a "three stage charging profile". So I suppose what follows in that section is a rather detailed description of a charging profile. And it does have terms that sound familiar, because they are terms also used for FLA batteries - Bulk, Absorption, and Float stages. During the Bulk Charging state a fixed current is applied until a pre-set voltage is reached. No specific current level is indicated, but later in the section it seems to discuss the current vs charging times for the Bulk charging stage. Says it should be as high a practical. Hmm. Optimal? Once the pre-set limit is reached, then it holds the voltage constant (rather then the current) and allows the current to drop below 0.5% of the battery’s rated Ah capacity as it charges. It gives the example that for a 100Ah battery, its fully charged when the current reaches 0.5A which is 0.5% of 100Ah. The units don't seem consistent to me (Amp Hours vs Amps) but that is what it says. So anyway, the "constant" voltage used during the Absorption stage is temperature dependent and is given in a table. So, pretty sure the numbers would be different for a FLA - meaning the so-called profile will differ a little bit. Once the battery is considered charged (and in this case the goal was 100% SOC), then it switches to a Float charge stage, where the voltage is reduced - again those voltages for the Float stage are given in the table. And I am pretty sure that the they would not match the so-called optimal voltages for an FLA battery.

Bottom line - what this Charging section describes, and calls a charging profile, will differ for a FLA because the voltages - in both the Absorption stage and the Float stage will be different. It its also describing the profile for a battery charger with a goal of reaching and sustaining a 100% state of charge.

Now, does the C8 charging system do that? No. It does not even target 100% state of charge, so its not normally operating in the Float stage - defined as occurring when the battery reaches full charge in the Lifeline technical manual. The C8 charging system spends most of its time in the Fuel Economy Mode, which is described in the C8 service manual as maintaining the open circuit voltage (their words not mine) neither discharging nor charging the battery. Whether or not one wants to call it a Float state, its not maintaining the battery at 100% SOC, but rather 80%, more or less. But a look at the slightly different voltages for an 80% SOC, or the voltage range described for the Fuel Economy Mode for the C8 which is 12.5 -13.1, its clear that its not really matching the charging profile prescribed for the AGM in the Lifeline technical manual. I doubt it even matches the "optimal" charging profile for an FLA, because that too would typically be for 100% SOC. Even if one wants to argue that the C8 charging system may charge the battery above 80% (it does have modes that use higher charging voltage, if headlights are on for example), the voltages used for those charging modes won't really match the voltages listed for the charging profile described in the Lifeline technical manual.

And finally, does it matter? Maybe - but we know folks regularly replace an FLA with an AGM with no issues - so as a practical matter it would appear that any difference in "optimal" charging profiles is negligible in practice - at least when installed in a car. I think if and when the batteries are connected to an external charger (which by the way is what the section in the Lifeline technical manual is really addressing) with a goal of reaching and then sustaining 100% SOC, the difference in the profiles will become important.

https://lifelinebatteries.com/wp-con...cal_Manual.pdf

 

"Optimum Battery Charging" is dependent on your objective:
GM and other manufacturers limit max lead acid battery charging, as they note with their charging algorithm, for fuel economy reasons:

Fuel Economy Mode
The BCM will enter Fuel Economy Mode when the estimated battery temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 amperes and greater than −8 amperes, and the battery state-of-charge is greater than or equal to 80 percent. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5 and 13.1 V.

The BCM will exit this mode and enter Charge Mode under some conditions including:
• The wipers are ON for more than 3 seconds.
• The estimated battery temperature is less than 0° C (32°F).
• Battery State of Charge is less than 80 percent.
• Vehicle speed is greater than 145 km/h (90 mph)
• System voltage was determined to be below 12.56 V
When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9 and 15.5 V, depending on the battery state of charge and estimated battery temperature.

BTW, in my 2020 C8 I observed after the car was parked for several days:

• On the way into town (~25 miles) the battery volts dash meter, read the alternator voltage of ~14.5 volts
• On the way home there would be a stepped change as the computer lowered the alternator voltage to ~13 volts. That was sufficient to supply all amperage needed to operate the Fans, Sound System etc BUT not high enough to further charge the battery more that the GM desired 80%.

I found the same thing with how they charge my 12 volt Li-Ion E-Ray battery:

• The E-Ray alternator charges to 13.3 volts which is about 85 to 90% capacity NOT the highest typical Li-Ion car batteries can be charges >14.0. Yep good enough to whatever is needed in the car. It NOT the max capacity if you are using Li-Ion batteries in your RV and want max capacity to power whatever when stopped.
• My GM sold CTEK battery charger is designed for both Lead Acid and Li-Ion charging does the same.
  • When charger was plugged in if the battery is already at 13.3 volts from alternator charging the GM Charger instantly shows per the LED indicator light 80% "usable" (per the institution manual.)
  • To reach the 100% charged LED indicator light took 4 hours and read 13.36 volts on my Fluke meter. Not the ~14+ volts 100% capacity.
  • But waiting 24 hours after charging (as an Internet source recommended) it reduced to 13.32 volts (essentially where the E-Ray alternator limits charging.)
  • GM doesn't say why but a number of internet sources say it reduces required charging energy and in the case of Li-Ion batteries extends life.

 

I have a 2025 with 150 miles. I am not comfortable with the way this battery drops voltage so easily when sitting or using accessories. 100k for a car? Chevy please don’t waste my time on the POS battery.
I ordered the Odyssey AGM.

Anyone know if the factory trickle charger is compatible with this AGM?