AGM Question

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So I'm reading the "AGM vs Traditional Battery" thread and see mention of re coding when switching to an AGM battery. Is this necessary? Do the auto stores do this? My 2014 F150 is probably ready for a new battery soon.
 
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Ontario, Canada
Originally Posted by Bear
So I'm reading the "AGM vs Traditional Battery" thread and see mention of re coding when switching to an AGM battery. Is this necessary?
This a new one on me, but it may depend on vehicle & MY
 
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394
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Texas
Seems to depend on the vehicle. My E60 BMW, I have to code my vehicle to provide the correct charging profile for FLA/AGM batteries. Charging an AGM battery the same way as it would an FLA battery would seriously decrease the battery life of that AGM. It's for this reason that I won't use AGM batteries in my older vehicles...they won't charge them correctly and I won't see the benefits of going AGM. Unless the vehicle sits for long periods of time or you have a rock crawler that bounces around a bunch, it's probably not worth it to pay extra for the AGM. If they're the same price, then flip a coin/buy whatever gives you the warm and fuzzies.
 
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Upstate NY
Originally Posted by TXCarGeek
Seems to depend on the vehicle. My E60 BMW, I have to code my vehicle to provide the correct charging profile for FLA/AGM batteries. Charging an AGM battery the same way as it would an FLA battery would seriously decrease the battery life of that AGM. It's for this reason that I won't use AGM batteries in my older vehicles...they won't charge them correctly and I won't see the benefits of going AGM. Unless the vehicle sits for long periods of time or you have a rock crawler that bounces around a bunch, it's probably not worth it to pay extra for the AGM. If they're the same price, then flip a coin/buy whatever gives you the warm and fuzzies.
Do you have first hand knowledge of AGM battery not lasting as long as they should when replacing a flooded cell in older vehicle? More than once?
 
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Originally Posted by Donald
Do you have first hand knowledge of AGM battery not lasting as long as they should when replacing a flooded cell in older vehicle? More than once?
An AGM battery requires a slightly lower float charge voltage than a flooded battery. Most automotive charging systems (designed for flooded battery) will output 2.4V/cell which is too high for AGM and will lead to sustained overcharging on long drives. We're talking a fairly small difference here, so the battery will still function and is not going to go up in smoke, but it will shorten the lifespan. No firsthand knowledge/experience needed, this is just plain fact. Thus the benefits of an AGM battery begin to disappear when used as a drop-in replacement for a flooded type, unless the charging system has some means of compensating.
 
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Here is a copy of the description of AGM batteries from Canadian Tire. As I mentioned above, I put in an AGM battery in a Silverado two years ago. It works great and is maintenance free. We've done a lot of cold starts with it with no issues. I don't feel a need for any Bittog Hand Wringing. I'll report back if there are any issues. Good luck.

Motomaster AGM.PNG
 
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8,806
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MA
Originally Posted by Pelican
Originally Posted by Bear
So I'm reading the "AGM vs Traditional Battery" thread and see mention of re coding when switching to an AGM battery. Is this necessary?
This a new one on me, but it may depend on vehicle & MY
I've basically heard of BMW requiring this. Mercedes doesn't, at least the years I have, maybe some of the newer models with aux batteries. My AGM in my 2008 E-350 is now 12 years old. Still original. Still fine.
 
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I put an AGM in my Traverse last without any programming. Things have been good so far. I noticed that the alternator drops down to 12V a lot more often now.
 
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394
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Texas
Originally Posted by Donald
Originally Posted by TXCarGeek
Seems to depend on the vehicle. My E60 BMW, I have to code my vehicle to provide the correct charging profile for FLA/AGM batteries. Charging an AGM battery the same way as it would an FLA battery would seriously decrease the battery life of that AGM. It's for this reason that I won't use AGM batteries in my older vehicles...they won't charge them correctly and I won't see the benefits of going AGM. Unless the vehicle sits for long periods of time or you have a rock crawler that bounces around a bunch, it's probably not worth it to pay extra for the AGM. If they're the same price, then flip a coin/buy whatever gives you the warm and fuzzies.
Do you have first hand knowledge of AGM battery not lasting as long as they should when replacing a flooded cell in older vehicle? More than once?
Twice. Had an Optima Battery in an '08 Navigator that began to test bad shortly after the 36 month warranty period and then a Deka AGM battery from O'reilly in a '99 Wrangler that lasted about 6 years. The Optima may have just been overall poor quality, but who knows for sure. The Deka battery, while great, didn't give me a longer service period than the FLA battery that was in there before. In both instances, both in vehicles without the option for switching to a dedicated AGM charging profile, I didn't really see any benefits from using AGM. Perhaps I just had bad luck. Aside from that, it's well known that AGM batteries are sensitive to overcharging. AGM certainly has its place like for frequent short trips, seasonal use, vibration/shock prone applications, vehicles equipped with stop/start systems, etc; my usage doesn't really fall into those descriptors.
 
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Texas
Originally Posted by 92saturnsl2
Originally Posted by Donald
Do you have first hand knowledge of AGM battery not lasting as long as they should when replacing a flooded cell in older vehicle? More than once?
An AGM battery requires a slightly lower float charge voltage than a flooded battery. Most automotive charging systems (designed for flooded battery) will output 2.4V/cell which is too high for AGM and will lead to sustained overcharging on long drives. We're talking a fairly small difference here, so the battery will still function and is not going to go up in smoke, but it will shorten the lifespan. No firsthand knowledge/experience needed, this is just plain fact. Thus the benefits of an AGM battery begin to disappear when used as a drop-in replacement for a flooded type, unless the charging system has some means of compensating.
Exactly my thoughts. I've had mixed results with AGM batteries in older vehicles that can't adjust the charging characteristics to help support an AGM's requirements. My E60 however can, but requires me to code it which is different than a simple battery registration.
 
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I am not debating the theory for charging an AGM. But in a vehicle that comes standard with a flooded have its charging setup perfectly for a flooded cell or is it just "pretty close" and maybe this "pretty close" is good enough for an AGM also.
 
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Atlanta,GA
Originally Posted by Bear
So I'm reading the "AGM vs Traditional Battery" thread and see mention of re coding when switching to an AGM battery. Is this necessary? Do the auto stores do this? My 2014 F150 is probably ready for a new battery soon.
Auto stores can do this and it depends on whether or not an AGM battery is approved for use by your vehicle manufacturer for your vehicle. Some manufacturers require coding and/or registration because battery size varies based on model and options (ex, heated seats). It basically goes like this. New battery but different CCA etc: Coding for change in size and registration to reset the charge profile. New battery is same as current battery: Registration to reset the charge profile. Personally if your vehicle is not designed to use AGM I would not go through the expense of buying one because you won't realize the full potential with regards to service life.
 
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Ontario, Canada
Originally Posted by Wolf359
Originally Posted by Pelican
[quote=Bear]So I'm reading the "AGM vs Traditional Battery" thread and see mention of re coding when switching to an AGM battery. Is this necessary?
I've basically heard of BMW requiring this. Mercedes doesn't, at least the years I have, maybe some of the newer models with aux batteries. My AGM in my 2008 E-350 is now 12 years old. Still original. Still fine.
Never owned a BMW, but did own the same MB as yours, bought it as a CPO 3yo with 10K miles on it, the battery went after 1 yr (4 yo) I think that because it wasn't used much the battery suffered. I replaced it with the same MB battery and never had any problems. The battery on modern cars performs a lot more tasks than before and an AGM will give you better performance, the only thing is that when it fails it will give no warning. The other thing is that one needs an "Intelligent" charger like C-Tek to keep them healthy.[/quote]
 
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2 years and running should be maintainable for any battery, AGM or Flooded. I've wondered if AGMs have an advantage where the newer programming reduces the float voltage for MPG. I've not measured out a full drive cycle, but cold my '18 F150 charges at 14.3, which my older vehicles settled down to once warm - when cold my older vehicles would start around 15, then taper down to 14.1 or so. I have to think that MFRs offering AGM as an option perhaps add a little extra fluid to the cells, or at least figure out the release valve pressure and any recombinant chemistries to offset the shortened life of running a battery that wants ~13.7V float in a vehicle looking to float at 14.1 or so. Then again, with start/stop and the typical discussions that suggests most starter batteries in new cars seldom make it over 80% SOC, a 14.1 (just WAGging) would not be a risk. I've got an H8 AGM shoehorned nicely into the F150 which calls for an H6. (It just happens that my trade had the H8 so I let the trade go with the new Ford H6 and I kept my used H8). The H8 is 3 years old but does not stay fully charged in the F150 - up until now I put a computerized charger on it when I think about it here and there. Recently, because #bitoglife I added a PV panel and charge controller to the fiberglass shell. It seems to take about 3 hours every day after I park it to reach a float voltage of 13.7, and then it stays there. Truck turns over just like coming off on of equalize charge on the computerized charger at home.
 
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Texas
Originally Posted by meep
2 years and running should be maintainable for any battery, AGM or Flooded. I've wondered if AGMs have an advantage where the newer programming reduces the float voltage for MPG. I've not measured out a full drive cycle, but cold my '18 F150 charges at 14.3, which my older vehicles settled down to once warm - when cold my older vehicles would start around 15, then taper down to 14.1 or so. I have to think that MFRs offering AGM as an option perhaps add a little extra fluid to the cells, or at least figure out the release valve pressure and any recombinant chemistries to offset the shortened life of running a battery that wants ~13.7V float in a vehicle looking to float at 14.1 or so. Then again, with start/stop and the typical discussions that suggests most starter batteries in new cars seldom make it over 80% SOC, a 14.1 (just WAGging) would not be a risk. I've got an H8 AGM shoehorned nicely into the F150 which calls for an H6. (It just happens that my trade had the H8 so I let the trade go with the new Ford H6 and I kept my used H8). The H8 is 3 years old but does not stay fully charged in the F150 - up until now I put a computerized charger on it when I think about it here and there. Recently, because #bitoglife I added a PV panel and charge controller to the fiberglass shell. It seems to take about 3 hours every day after I park it to reach a float voltage of 13.7, and then it stays there. Truck turns over just like coming off on of equalize charge on the computerized charger at home.
Does Ford recommend only AGM batteries in their newer vehicles, especially those equipped with auto stop/start?
 
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Never had any issues substituting AGM batteries for standard batteries in various older vehicles with no ability to program them for charging profiles etc.
 
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Atlanta,GA
Originally Posted by meep
2 years and running should be maintainable for any battery, AGM or Flooded. I've wondered if AGMs have an advantage where the newer programming reduces the float voltage for MPG. I've not measured out a full drive cycle, but cold my '18 F150 charges at 14.3, which my older vehicles settled down to once warm - when cold my older vehicles would start around 15, then taper down to 14.1 or so. I have to think that MFRs offering AGM as an option perhaps add a little extra fluid to the cells, or at least figure out the release valve pressure and any recombinant chemistries to offset the shortened life of running a battery that wants ~13.7V float in a vehicle looking to float at 14.1 or so. Then again, with start/stop and the typical discussions that suggests most starter batteries in new cars seldom make it over 80% SOC, a 14.1 (just WAGging) would not be a risk. I've got an H8 AGM shoehorned nicely into the F150 which calls for an H6. (It just happens that my trade had the H8 so I let the trade go with the new Ford H6 and I kept my used H8). The H8 is 3 years old but does not stay fully charged in the F150 - up until now I put a computerized charger on it when I think about it here and there. Recently, because #bitoglife I added a PV panel and charge controller to the fiberglass shell. It seems to take about 3 hours every day after I park it to reach a float voltage of 13.7, and then it stays there. Truck turns over just like coming off on of equalize charge on the computerized charger at home.
With regards to start/stop don't forget all the other sources drawing power when the engine isn't running: Radio, Climate control (Fan), Heated Seats, Wipers, Lights. AGM should last 7-9 years.
 
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Originally Posted by TXCarGeek
Does Ford recommend only AGM batteries in their newer vehicles, especially those equipped with auto stop/start?
OEM battery was flooded, so I don't think so.
Originally Posted by BMWTurboDzl
With regards to start/stop don't forget all the other sources drawing power when the engine isn't running: Radio, Climate control (Fan), Heated Seats, Wipers, Lights. AGM should last 7-9 years.
Total Guess. Full headlamps - 10A. ECU 5A. Radio 5A if it's loud. cabin blower ramps down to speed 1/10, 1 A. Rarely stays in auto-stop for more than 30 seconds. So that's 20A for 30 seconds, a total drain of 0.17AH - which is 0.3% of battery capacity. It's not a significant load, BUT it does diminish the battery's ability to maintain a finished charge, AND it does add to the total cycling of the battery, even though the restart is very brief - it's like it fires on the first compression stroke rather than having to always find cyl1 TDC. We just replaced a 2.5 year old oversized AGM in my wife's CRV. It was 6 months old when we bought it, BUT otoh AGM tolerates inactivity better with reduced self-discharge. For all these reasons - I haven't been able to form an opinion on how long they 'should' last. Too many variables. But I hope you are right - that I can get 7 years out of it. If I can't, I'll go back to FLA.
 
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Baltimore, Maryland, USA
Originally Posted by BMWTurboDzl
Personally if your vehicle is not designed to use AGM I would not go through the expense of buying one because you won't realize the full potential with regards to service life.
What if it's a vehicle that sits a lot?
 
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