12v SLA AGM DeepCycle 5AH battery bubbling problems?

I thought this was an okay place to ask
Ive got a 12v battery and when I take the plastic cover/lid off to expose the battery cap vents

I notice 2 things about the battery

Theres teeny tiny droplets of liquid all around. (wiped up with a napkin and q-tips)
inside the battery vents when I look with a flashlight into the cells I notice theres a decent "layer" of excess liquid floating on top of the seperators about a mm thick sloshing around wanting to get out.

I went in the cells with an army of q-tips and slowly soaked the excess away one q-tip at a time until it didn't slosh/move when i moved the battery gently and tilted it slightly.
cleaned everything up with a few more q-tips and now theres no problem with excess liquid. and put all the used q-tips into a sandwich bag to throw out

It was like that when I bought it brand new. it read 12.78v fresh out of the box.
When I first took the plastic cover/lid off the rubber caps were sucked inwards.
after charging they were outwards and had a bit of pressure in them but not much. (just enough for a little bit of bubbles to come out under them when i push on them with my finger)

did I get a defective battery? or is it like super fresh new from the factory and possibly had excess fluid in it that squrged out on the first use or so?

it has very smooth clean-room like surfaces on the outside so i'm assuming its new and hasnt been used. with a label on the front

on charging it couldn't of been overcharging because the current dropped to only 0.2A and the voltage only went to 14.6v at the very end of the charging stage. and the battery stayed room temperature.
I was monitoring the voltage the whole time and it slowly rose to 13.2v then slowly rose to 14.6v and stayed around there pretty closely. with the current dropping gradually.

On the battery it says Cycle voltage 14.4v to 15v and standby 13.5v to 13.8v
that sounds like its within charging range?

What could really be the cause of the excess liquid escaping?

I'm thinking of super-gluing the plastic cover/lid back on for now.

If you bought it new, why would you open it up? I'm not an expert on AGM batteries, so I don't know if there is supposed to be liquid over the cell separators. However, if you got it new then it must have had some sort of warranty, that if you pried anything off, that you just void.

Traditionally batteries have a layer of electrolyte over them, and they are exactly as they should be from the factory.

AGM batteries are not dry cell batteries, they are still filled with liquid electrolyte, they are just spill resistant.

When things come from the factory, they are generally not bad. However, heating from charging can cause some liquid to 'surface' in agm batteries. What do you call a decent layer? 1/8th in, 3/16th in?

Personally, when I buy a new battery, I don't take it appart. AGM and gel batteries are widely considered to be non-serviceable. Even serviceable flooded batteries are rare nowadays.

We never agreed to any warrenty (thre wasn't one when we bought it) but I thought it was extremely dangerous since there was liquid all over the top of the battery underneath the plastic lid/cover in little droplets and i thought to clean it off so it doesn't escape out onto something and cause damage.
I tried letting it sit overnight and it was still about 1-2mm of liquid floating on top of the seperators. if i had been charging the battery on its side it would of dripped out a lot escaped past the caps and ruined whatever was under the battery
I had to go in with a napkin on top of the battery under the plastic cover because there was quite a bit of it that got out of the vents (nothing seems wrong with the actual vents though)

also i can't get a reading of the battery's full charge level because of something strange with the voltage reading of the battery.
it charged up fine but 2 days later it's still at 13.08v!! is that normal for an AGM battery even after putting a 2-3 amp load on the battery for a good minute the day i charged it it eventually rose back up to 13.10v now its at 13.08

All I can say is wow.
If there was a warranty of any kind I'm sure you voided it the second you pryed open a sealed battery.

AGM batteries read a slightly higher resting voltage than flooded batteries, but not a whole .4V. Resting voltage should be 12.8V max on an AGM with no surface charge. To remove surface charge, run a 10A load for about 100 seconds, then give the battery 5-8 minutes to recover. That is your resting voltage, after a day however the surface charge should have dissipated.

Surface charge is what happens when air bubbles form on the plates during charging. That results in a higher than normal voltage, up to 13.8V. On flooded batteries this charge drops to about 12.6-12.75 after about an hour. Part of that is the bubbles rising to the top and escaping the battery. An AGM battery has a fiberglass mat that prevents the movement of these bubbles and thus will hold a surface charge for a while longer. How much longer, I have no idea. However, removing the surface charge is the same, 10ish amp load for about 1.5 to 2 minutes, followed by a 5-8 minute recovery period. Then retest the voltage to see what its at.

At this point i'd load test the battery to see if it will hold a charge. I'm going to guess you dont have a carbon pile, so you're going to have to do it the manual way.

In a vehicle, turn on all your lights, internal and out. Turn on all electrical loads including fans and defrosters, seat heaters too. if you have any cigarette lighter accessories that draw some power, plug those in too.

The goal is to try and draw about 100-150 amps from the battery. Give the battery about 1-2 minutes on this load and test the voltage every 30 seconds or so. It shouldn't drop below about 12.1V. After 3 minutes, disconnect all the loads and give the battery a 10 minute recovery time, the voltage should rise back to 85-95% of the original charge voltage (no surface charge).

100 amps on a 5AH AGM battery?? Yikes!! thats like a short circuit to it! I dont think it'd be able to give out that much even if only for a few milliseconds

It'd run flat really quickly even under a 10 amp load I bet.
its like the kind for a kids small electric power wheels vehicle

I did try a 220W vacuum cleaner with a power inverter which takes about 20 amps from the battery. Easily ran it with no problem. voltage only dropped to about 11.5-11.8v under that load. and after a few minutes with no load it still went back up to about 13v and the next day it was still 13.08v
Only ran it for a few seconds though. Nothing got warm.

Was able to power my computer. monitor. and stereo as well as a 30-watt fan for about an hour before the voltage dropped to 10.6v battery stayed cool the whole time as well as the wiring
the voltage immediately went back up to 11.5v after i turned off the inverter
it seems to be a good battery but it seems to hold a surface charge for what seems like ages?

The charger im using is 2 amps rating 3-stage which says its for "all battery types and sizes" and AGM is on the list on the original packaging so I thought it'd be fine.
it works for 6v and 12v batteries. it turns off once the current drops below about 0.2A then a few hours later it periodically gets the battery to 13.8v then cuts off. with a big green light that comes on when its fully charged and ready to go.

realflow100 said:

100 amps on a 5AH AGM battery??

Click to expand...

I thought you made a typo when you put that down and forgot a couple zeroes. To be honest, I didn't know they made AGM batteries below 40AH. In that case, divide the load by 10, or 10A, which you did.

I did some looking around in some old books I had from college and found a few section relevant to AGM batteries.

Surface charge can take up to 2 days to dissipate and come to a resting voltage. Resting voltage should be between 12.8-13.2V for a fully charged battery.

They are considered non-serviceable, and should be replaced when suspect of being bad. AGM batteries do not work well with de-sulfation devices, not much happens.

It seems that your battery is fine. I'm suspect of the liquid on top, I have no idea what that was all about. However, i'd refrain from doing that again without a call to the manufacturer to see if they are supposed to be like that when new.

At least with some flooded cells i've used, when first filled they take about 24Hrs to fully settle to the proper electrolyte height. We would measure the battery water and acid being put in to make sure it wasn't under filled or off on the mix. Then we would charge them and give them 48Hrs to settle (24 for surface charge and 24 for the liquid to settle) as the liquid level rises when charging. After that, we would recheck to make sure the electrolyte was at the correct level.

It is this model
https://www.amazon.com/Replacement-Battery-12V-DEEP-CYCLE/dp/B00BMUPXTU/ref=sr_1_65

it is only 5 amp hours but it works perfectly for my situation as emergency power in backup situation. or even to run things off solar power since ive got a 20 watt 12v solar panel and I might set that up with a charge controller.
I just woke up sorry if theres loads of typos havent had my coffee yet P: