Should an AGM battery make sounds while charging?

foolios

I have these Chrome Batteries for solar backup. I purchased a quick charged that stated it is for standard, AGM, and gel batteries.
When I charged my 75AH battery, it made some gurgling type sounds.
I then tried to see what happened on my 35AH battery and I heard the same sounds.
Even after fully charging the 35AH battery, it did not have any smells of vented gas.
Can anyone tell me if it's normal to hear sounds in the battery during charging/discharging?

THanks in advance.

BB.

Re: Should an AGM battery make sounds while charging?

Flooded cell batteries--yes you will probably hear gurgling as the approach full charge.

Sealed AGM type batteries--You should not hear much noise. They cannot be "gassed" very much or they will over heat the catalyst (Hydrogen/Oxygen recombiner like palladium or similar) and vent (you may hear a hissing noise as the pressure vent releases). Not a good thing to do to AGMs.

For GEL type batteries--If you hear any noise, they are probably in the process of being destroyed (GEL should not gurgle--will get permanent bubbles in electrolyte, venting not good either).

-Bill

westbranch

Re: Should an AGM battery make sounds while charging?

Well there are 53 different AGM batteries listed....

Only if they are FLA batteries should you have heard any sounds...

If they are AGM, No, there should be no sounds heard, if there were you have overcharged them. Maybe a little maybe a lot.

Did you take any Voltage readings as the charge was being done? or after you stopped the charge?

hth

CALLD

Re: Should an AGM battery make sounds while charging?

The short answer is they should not make any sounds at all. The problem is most likely with the charger though. AGM batteries are usually marked with specific charging parameters on the battery, on my 260AH batteries it says the following:

Constant voltage charge @ 25°C:
Standby use 13.6-13.8v
Cycle use 14.4-14.8v
Initial current 78A

Check that your charger is not exceeding the initial current limits for your battery and check the voltage with a multimeter throughout the charge. If your batteries do not have these parameters stamped on them use the above for every 12volts of battery, and make sure the current does not exceed C/4 (25Amps for every 100AH of battery) initially. If the voltage starts to exceed 14.8v for a 12v battery disconnect the charger immediately and never ever use it again!

gww1

Re: Should an AGM battery make sounds while charging?

called
How long would you absorb at 14.4 volts after you reach it.
Gww

CALLD

Re: Should an AGM battery make sounds while charging?

gww1 wrote: »

called
How long would you absorb at 14.4 volts after you reach it.
Gww

Gww1,

Time at absorb varies depending on the bulk charging current available, but generally 2 hours is the norm. I have it set to switch to float when the batteries are accepting less than 5amps for my 260Ah batteries. That is approximately C/50. When the current acceptance drops below this then generally no further "real charging" chemical reactions are taking place anymore, the energy is then going towards electrolysis of water and heating.

gww1

Re: Should an AGM battery make sounds while charging?

calld
Thanks, I had this come up on the outback forum and I didn't know how to help.
gww

foolios

Re: Should an AGM battery make sounds while charging?

It appears I may have discovered the problem.

I had the battery in parallel with another battery. I did unhook the positive wire from the one battery to the other thinking this would be enough to isolate the battery during charge.
It appears I was mistaken; when that one wire was still on both negative battery terminals, the charge voltage climbed to 15.2V.
When I removed that connection, the charge voltage stopped at a peak of EDIT: 14.4V.

If someone could explain why it was not ok to leave one side of posts still connected, I would appreciate the lesson.

westbranch

Re: Should an AGM battery make sounds while charging?

A picture of what you did might help...:roll:

BB.

Re: Should an AGM battery make sounds while charging?

The long term charging voltage at ~75F should be around 14.2-14.4 volts maximum... Even 14.8 volts is usually too high for AGMs for any extended length of time.

-Bill

foolios

Re: Should an AGM battery make sounds while charging?

BB. wrote: »

The long term charging voltage at ~75F should be around 14.2-14.4 volts maximum... Even 14.8 volts is usually too high for AGMs for any extended length of time.

-Bill

You are correct. I was mistaken. I should have written that the high was no higher than 14.4V or 14.44V to be more exacting.

So far so good; and I've went so far as to test placing the two batteries back in parallel and quick charging it in that manner with no issues.

It had to do with my leaving the negative posts of the two batteries connected while having have removed the wire that connected the two positive terminals of the batteries together.
I do not understand why that was an issue.

I am going to keep an eye on it and report back with more information.

As for a pic, I can try to take one or draw up the connections.

EDIT: http://i1121.photobucket.com/albums/l520/foolios43/Untitled_zpso7vnkfri.png
I may have had more than one battery connected with the negative in parallel like this. Not gonna retry to verify though...