Club Cobra Keith Craft Racing  

Go Back   Club Cobra > Manufacturers, Engine Builders, tools, and parts. > ERA---Speak with Bob Putnam

MMG Superformance
Nevada Classics
MMG Superformance
Main Menu
Module Jump:
Nevada Classics
Nevada Classics
Keith Craft Racing
Keith Craft Racing
Advertise at CC
Banner Ad Rates
Keith Craft Racing
Keith Craft Racing
Keith Craft Racing
MMG Superformance
March 2024
S M T W T F S
          1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31            

Kirkham Motorsports

Like Tree1Likes
  • 1 Post By Argess

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 05-24-2022, 07:01 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2009
Cobra Make, Engine:
Posts: 409
Not Ranked     
Default AGM vs traditional flooded battery

I've been thinking of replacing my battery with an AGM one, however I'm not sure if my 1960s style Ford alternator and regulator will over or undercharge it and from what I understand, AGM batteries are susceptible to damage from this. Opinions welcome. T-Y.

ps: I can't seem to find a battery with end tabs to suit the mounting and those J-hooks with wing-nuts look they will be a pain to fiddle with under the fender, so I'll stick with a 24F7 and use a strap around the battery and tray.
Reply With Quote
  #2 (permalink)  
Old 05-24-2022, 07:09 PM
Sycraft's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2021
Cobra Make, Engine: ford 302
Posts: 290
Not Ranked     
Default

if the output of the alternator is too high, you will shorten the lifespan of the AGM. I would not spend the additional money on an AGM in our application unless it was a modern powerplant with a charging system that adjusts output as needed.
Reply With Quote
  #3 (permalink)  
Old 05-24-2022, 07:31 PM
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2021
Cobra Make, Engine:
Posts: 533
Not Ranked     
Default

I run an AGM in my ERA because I don't want to have to check the fluid level. I have to remove the RR wheel to access the battery compartment. I run just a one wire 100a alternator with its internal regulator and have not had any issues. My 2˘.
Reply With Quote
  #4 (permalink)  
Old 05-25-2022, 05:54 AM
DanEC's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2009
Location: Little Rock area, AR
Cobra Make, Engine: ERA Street Roadster #782 with 459 cu in FE KC engine, toploader, 3.31
Posts: 4,480
Not Ranked     
Default

I use a cutoff on my under-hood acid flooded battery and just replaced it after 10 years. It is a pain to replace through the wheel well but every 10 years isn’t bad. - except I’ll be 80 then, bummer.
__________________
ERA 782 Running
https://www.youtube.com/watch?v=Cfge...b1-77fqwFRu7c]
Reply With Quote
  #5 (permalink)  
Old 05-25-2022, 08:15 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2009
Cobra Make, Engine:
Posts: 409
Not Ranked     
Default

I was mostly interested in the AGM as it is maintenance free and won't spill if tipped over. The battery in my ERA is under the right front fender. You have to take the valve cover off to remove or install it. For installing it, the battery slips in at an angle and finally gets in place on its side. Then you rotate it upright. Checking the water level of at least 3 of the cells is difficult too. So the issues are similar to Karl's.

As I can no longer find the proper 24F7 battery with the hold-down side tabs, I'm free to choose something else, so I was investigating the AGM batteries but research showed some issues, so I thought I'd ask here.
Reply With Quote
  #6 (permalink)  
Old 05-25-2022, 08:20 AM
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2021
Cobra Make, Engine:
Posts: 533
Not Ranked     
Default

DanEC, You've had very good luck with your battery, enjoy! Our Arizona desert is extremely harsh on flooded batteries. They have been greatly improved the last few years and now sometimes last more than 2 or 3 years as in the past.
Reply With Quote
  #7 (permalink)  
Old 05-25-2022, 12:56 PM
Mongoose930's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2011
Cobra Make, Engine: Hi-Tech
Posts: 716
Not Ranked     
Default

I am using a Deadnutson alternator with AGM batteries and I have had no issues in 3 years:
https://www.deadnutson.com/1965-1971...e-alternators/

In my limited experience, I think you need an AGM specific battery charger / tender for AGM batteries, but my standard alternator has worked fine.
Reply With Quote
  #8 (permalink)  
Old 05-25-2022, 02:28 PM
twobjshelbys's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2009
Location: Las Vegas, NV
Cobra Make, Engine: Shelby CSX4005LA, Roush 427IR
Posts: 5,450
Not Ranked     
Default

Isn't the Optima Red Top AGM class? I ran a 2x6V configuration all the time I owned my Cobra and never had any alternator or other charging issues.

In addition the Optima I had in my Ford GT lasted over 7 years being on a Battery Tender. (The Ford GT battery is an Optima Red Top with a Ford label.)
__________________
Cheers,
Tony
CSX4005LA

Last edited by twobjshelbys; 05-25-2022 at 03:50 PM..
Reply With Quote
  #9 (permalink)  
Old 05-25-2022, 03:35 PM
CJ428CJ's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2000
Location: Livermore, CA
Cobra Make, Engine: ERA #629, BBM Side Oiler Block, 482ci, Richmond 5 speed
Posts: 851
Not Ranked     
Default

I've been using the Optima 35R in my ERA with the battery under the right front fender. It does have the end tabs to allow the ERA provided battery hold down to be used (although I did have to put a spacer under the battery). I like it so much better than the old lead acid battery I used to use. The lead acid battery would "sweat" acid which would drip down and stain my stainless pipes. I've had the Optima for 3-4 years with no problems (and I use a 120A 1-wire alternator).

Chris
Reply With Quote
  #10 (permalink)  
Old 05-25-2022, 07:19 PM
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2003
Location: Gurnee, IL
Cobra Make, Engine: Kirkham #259
Posts: 1,393
Not Ranked     
Default

Quote:
Originally Posted by twobjshelbys View Post
Isn't the Optima Red Top AGM class? I ran a 2x6V configuration all the time I owned my Cobra and never had any alternator or other charging issues.
Same for KMP259 for and we use a single wire Alternator..
__________________
Morris
Reply With Quote
  #11 (permalink)  
Old 05-26-2022, 06:08 PM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2009
Cobra Make, Engine:
Posts: 409
Not Ranked     
Default

I’ve done a little more research and as far as I’m concerned, all those “positive” attributes of an AGM battery are all unfortunately outweighed by the following “negative” comments I found on the net:

1/ https://www.repairsmith.com/i/blog/agm-vs-lead-acid/

Flooded lead acid batteries are much more tolerant to overcharging than AGM batteries. The sealed aspect of AGM batteries makes them more prone to thermal runaway, which can be triggered by overcharging. Even if you discount thermal runaway, overcharging will shorten an AGM battery’s lifespan faster. So, when charging an AGM battery, use a regulated battery charger to control the voltage and current going into the battery.

Note: Thermal runaway is when a battery generates too much heat than it can dissipate. The battery will dry out and melt, release toxic chemicals, and cause fires or explode in extreme cases. Nearby batteries will be affected and may result in a domino effect.


2/ https://batteryuniversity.com/articl...-glass-mat-agm

As with all gelled and sealed units, AGM batteries are sensitive to overcharging. A charge to 2.40V/cell (and higher) is fine; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages). Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell); a direct replacement with a sealed unit could overcharge the battery on a long drive.

AGM and other sealed batteries do not like heat and should be installed away from the engine compartment. Manufacturers recommend halting charge if the battery core reaches 49°C (120°F).


Yes, I’ve never heard of this happening, and I know many Cobra owners use an AGM battery, but I’m sort of a low risk fellow at times. Too bad though. I almost bought one.
Sycraft likes this.
Reply With Quote
  #12 (permalink)  
Old 05-27-2022, 04:54 AM
DanEC's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2009
Location: Little Rock area, AR
Cobra Make, Engine: ERA Street Roadster #782 with 459 cu in FE KC engine, toploader, 3.31
Posts: 4,480
Not Ranked     
Default

Argess - are you dealing with an ERA? If so you should be able to remove the battery through the wheel well after removing the tire and the liner panel, and without tipping. Possibly early ERAs didn’t have this feature - not sure.
__________________
ERA 782 Running
https://www.youtube.com/watch?v=Cfge...b1-77fqwFRu7c]
Reply With Quote
  #13 (permalink)  
Old 05-27-2022, 06:26 AM
Sycraft's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2021
Cobra Make, Engine: ford 302
Posts: 290
Not Ranked     
Default

That was my answer...... I work in the industry and deal with alot of batteries, do not even get me started on Optima batteries, I would never own one. Seen too many issues in applications.


Quote:
Originally Posted by Argess View Post
I’ve done a little more research and as far as I’m concerned, all those “positive” attributes of an AGM battery are all unfortunately outweighed by the following “negative” comments I found on the net:

1/ https://www.repairsmith.com/i/blog/agm-vs-lead-acid/

Flooded lead acid batteries are much more tolerant to overcharging than AGM batteries. The sealed aspect of AGM batteries makes them more prone to thermal runaway, which can be triggered by overcharging. Even if you discount thermal runaway, overcharging will shorten an AGM battery’s lifespan faster. So, when charging an AGM battery, use a regulated battery charger to control the voltage and current going into the battery.

Note: Thermal runaway is when a battery generates too much heat than it can dissipate. The battery will dry out and melt, release toxic chemicals, and cause fires or explode in extreme cases. Nearby batteries will be affected and may result in a domino effect.


2/ https://batteryuniversity.com/articl...-glass-mat-agm

As with all gelled and sealed units, AGM batteries are sensitive to overcharging. A charge to 2.40V/cell (and higher) is fine; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages). Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell); a direct replacement with a sealed unit could overcharge the battery on a long drive.

AGM and other sealed batteries do not like heat and should be installed away from the engine compartment. Manufacturers recommend halting charge if the battery core reaches 49°C (120°F).


Yes, I’ve never heard of this happening, and I know many Cobra owners use an AGM battery, but I’m sort of a low risk fellow at times. Too bad though. I almost bought one.
Reply With Quote
  #14 (permalink)  
Old 05-27-2022, 07:41 AM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,889
Not Ranked     
Default

My last two Interstate Mega-Tron batteries have both lasted 7 to 8 years in my ERA and probably would have lasted longer had I not broken down and replaced them. And I performed no maintenance on them whatsoever during all that time. Never even looked at the water levels. I would occasionally peek at the terminals to see if there was an abundance of that funky white stuff on them, but there was never enough to warrant doing anything so that's it. I wouldn't replace the battery in there with anything else.
Reply With Quote
  #15 (permalink)  
Old 05-27-2022, 08:33 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2009
Cobra Make, Engine:
Posts: 409
Not Ranked     
Default

I've had a similar experience Patrick. I think I got my Cobra on the road back in 1997 and have just now had my 2nd battery fail. Like you, I never checked the acid/water, however on this second battery, the level was down almost a half inch in each cell. That didn't do it any good even though it lasted a long time.

As previously mentioned, my issue has been all new batteries do not have the clamp down end tabs. Also manipulating the battery into the battery tray might result in spillage with a vented battery. (Dan: mine is an older ERA and doesn't have that access panel)

I have a strap and a parachute buckle to fix the first problem. I'll just have to check for chafing of the strap for a while. The latter issue is to go with a sealed flooded lead acid battery.

I still havn't completely given up on AGM as so many people claim success, and to be truthful, I can't see an extra 1/2 volt from the alternator/regulator causing much of a problem by generating significant heat. Even if the float draw was 5 amps, that's only an extra 2.5 watts. Then again, I'm not sure what happens when you exceed the float voltage on an AGM.

There's a lot of conflicting information. Many articles claim not to have an AGM battery in the engine compartment due to heat, but other articles state that an AGM battery handles heat better than a traditional lead acid battery.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 06:11 PM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: CC Policy
Links monetized by VigLink