Strange Behaviour of AGM Battery

E

ecotourist

Joined
Jul 9, 2008
Messages
4,488
Location
British Columbia, Canada
Having just bought a new car, our trusty Honda has been parked for about 10 days, maybe as much as 2 weeks. It has a fairly new AGM battery.

This morning when I went to start it, the whole car was completely dead. Windows wouldn't roll down and it made absolutely no effort to start. Strange.

So I put my CTEK charger on it. The battery was so dead it wouldn't even show whether I had the correct polarity. I turned the charger on and within 30 seconds (less probably) it showed the battery as being fully charged. I took the charger off and the engine started easily. Even stranger.

It seemed as though the battery just needed a jolt to get back to life and then everything was fine. Does anyone understand what just happened?

For good measure the hood supports failed too this morning. Makes you wonder if the car was sulking. :unsure:
 
Had the same issue with a Duracell/DEKA 24F AGM battery. The issue happened sporadically, often 2-3x/month. I think there is an internal failure in the battery itself.

Sams Club initially refused to warranty it but did a one-time exception.
 
NitroM3 said:
Load test the battery.
If there is any problem even internal a good Digital Load Tester will fail the battery.
Click to expand...
Mine was tested with two midtronics testers, our shop tester and an old-school load tester. All of them passed the battery.
 
The Critic said:
Mine was tested with two midtronics testers, our shop tester and an old-school load tester. All of them passed the battery.
Click to expand...
Ok ? well your are in a shop and understand batteries I presume and how they are made. so..... your term *internal failure... ??? sure!
Reminds me of Holley 1850 and all the customers returning them and stating the term "internal vacuum leak" LOL
 
ragtoplvr said:
The lead connection between cells is cracked. It spot-welds it's self and makes connection until some mechanical stress happens and it opens. It will eventually fail as the crack widens from the arcing. Usually after warranty
Click to expand...
Yes and in a load test with a fully charged battery in your example the battery would fail the test.
 
Exit32 said:
Most likely an intermittent connection at the battery. When you connected the charger, a better connection was made.
Click to expand...
That's a reasonable theory and could be correct.

The battery posts were fairly clean but not "real clean". And I clamped onto the leads and not onto the battery posts which I think is against that theory. And I would have thought that if the battery was fully charged but the connections were bad there would have been at least some effort to start.
 
ragtoplvr said:
The lead connection between cells is cracked. It spot-welds it's self and makes connection until some mechanical stress happens and it opens. It will eventually fail as the crack widens from the arcing. Usually after warranty
Click to expand...
Sounds plausible.

The battery is not quite 2 years old and it has a 5 year warranty. So it has lots of time to completely fail.
 
If you have a full load test, at an actual 200 or 300 amps. No hand held tester can do that. NO room for the heat dissipation. Handheld condition tester said it was fine. A ew seconds on the old big load tester and it was 0V
 
ragtoplvr said:
If you have a full load test, at an actual 200 or 300 amps. No hand held tester can do that. NO room for the heat dissipation. Handheld condition tester said it was fine. A ew seconds on the old big load tester and it was 0V
Click to expand...
I don't know about you but I test a battery immediately after it is fully charged warm or better HOT... this way you get unquestionable test result. ;)

Understanding the 12 volt system :cool:
 
@NitroM3 What do you think I should do?

Clean the posts and have the battery load tested? And if it tests okay, just wait to see if it happens again?

One point of information is that the car has been parked outside and it's been quite hot - mid 30s Celcius (say 90 - 95 F).
 
ecotourist said:
@NitroM3 What do you think I should do?

Clean the posts and have the battery load tested? And if it tests okay, just wait to see if it happens again?

One point of information is that the car has been parked outside and it's been quite hot - mid 30s Celcius (say 90 - 95 F).
Click to expand...
Good point ecotourist but the unless the hood was open the hood acts as somewhat like thermal barrier and besides most batteries are exposed to much higher temperatures in normal use and even extreme heat during heat soak when the engine is first shut off . This is for batteries mounted and located directly in the engine compartments.
 
ecotourist said:
Having just bought a new car, our trusty Honda has been parked for about 10 days, maybe as much as 2 weeks. It has a fairly new AGM battery.

This morning when I went to start it, the whole car was completely dead. Windows wouldn't roll down and it made absolutely no effort to start. Strange.

So I put my CTEK charger on it. The battery was so dead it wouldn't even show whether I had the correct polarity. I turned the charger on and within 30 seconds (less probably) it showed the battery as being fully charged. I took the charger off and the engine started easily. Even stranger.

It seemed as though the battery just needed a jolt to get back to life and then everything was fine. Does anyone understand what just happened?

For good measure the hood supports failed too this morning. Makes you wonder if the car was sulking. :unsure:
Click to expand...

If it happens again, see if you can measure voltage, and if a good slap fixes it.... I've seen several batteries with internal breaks, mostly of the same type. They behave exactly like you describe. Non were AGM though, so not related to that...
 
Chris142 said:
Tell me more. I ran those carbs for years with no troubles.
Click to expand...
There is nothing to tell. Most that bought them didn't know how to set them and always used the internal vacuum leak as a reason to return them. There is no such thing in an 1850. But also most really did not know how to properly set up and adjust them either. The 1850 was and still is a universal carburetor. In the hands of the right people that know how to set them up and adjust them it is a fantastic carburetor. I sold them all day long 79.95 LOL Ya look what they are now. Then you need to invest another addition amount in jets ,springs, pump cams etc. to set them up on your engine . The nice thing I was an hired by Holley as an Rep for warranty acceptance right threw my own store. I was also known for this and on Test and Tune nights at the local Drag Strip I would make 100 buck telling a guy I could make his car run quicker ET's in less then 2 minutes. LOL if you worked on 1850 or any holly you should know what I did. LOL ;)
 

Attachments

  • IMG_20210818_151840565_resize.jpg
    IMG_20210818_151840565_resize.jpg
    160.1 KB · Views: 22
  • IMG_20210818_151904806_resize.jpg
    IMG_20210818_151904806_resize.jpg
    190.3 KB · Views: 22
Prob internal failure starting to show up. I will say we have waaaaay more issues with agm batteries than the good old lead/acid ones. I'd never buy an agm unless it was inside car and could not be vented...not a fan of them
 
You must log in or register to reply here.

Similar threads

F
Can battery die if not being used?
Replies
16
Views
809
bbhero
I
Napa AGM CCA dropped 10% after 2 months
Replies
12
Views
1K
benjy
Propflux01
AGM Battery Life
2
Replies
30
Views
5K
Thermo1223
Bailes1992
Disconnecting Negative Battery Sensor
Replies
12
Views
641
Craig in Canada
Cujet
DC arc welder restores sulfated golf cart batteries.
Replies
8
Views
1K
Cujet
Back
Top