2 months lead acid battery - today noticed sulfation and just a bit swollen

[terry98]

Hi, I have a 2 months old solar setup consisting of..
- 2x 6V225AH Interstate batteries (2S setup)
- 1x 355W panel (40v 9A max power)
- EPEVER 2210AN Charge controller (20 Amps max)
- 800w pure sine inverter Wzrelb


I use the batteries like every two days, this is because I drain the batteries to around 12.1v and 12.2v while playing or just watching TV (nintendo switch, sony 5.1 sound bar with subwoofer and samsung 40" HDTV) and because where I live I only get like 1hr of full solar, my panel is behind the bars of a 2nd floor balcony and cant get it installed in the roof . So I leave them for 2 days without use because I normally get 200Wh or so in a full day charge.

Today I noticed some sulfation in the positive lead and a bit of roundness above the battery and I dont know what can I do.. before using the battery I noticed that it measured 12.9v for 2 days, I don't really know if they were fully charged or if the controller can get them to float voltage. Any ideas or help???

 

[gnubie]

When you measured 12.9v was the battery being charged? If it's being charged it is no where near full charge. The charge controller, with power from the panels of course, will hold the battery around 13.8v once it has charged.

There shouldn't be any gunk forming on the + lead / terminal. If there is it sounds like there is moisture involved.

 

[Ped]

Thats not sulfation. It might be corrosion but sulphation isnt something you can see from the outside.

with lead acid you cannot just put 9 amps into a 225ah bank. You HAVE to give them at least .1c (10%). You HAVE to get get batteries to 14.6v and hold that voltage until the amps going in taper below .5% (1a) minimum everyday.

Even if you have 25 amps of solar it takes many hours to fill a lead acid battery. Like 8+ hours. The sun is not out long enough this time a year to charge them no matter how many panels you have.

With only 1hr of sunlight your options are to get a battery charger or get a lifepo4 and at least 2 more panels....or lower your load.

 

[terry98]

When you measured 12.9v was the battery being charged?

nop, it was night time and the panels were already "sleeping" so I assumed it was well charged.

If there is it sounds like there is moisture involved.

well the batteries are in the same balcony in a corner where the sun does not hit directly but they normally get around 30 celsius but is not humid.

 

[terry98]

Thats not sulfation. It might be corrosion but sulphation isnt something you can see from the outside.

with lead acid you cannot just put 9 amps into a 225ah bank. You HAVE to give them at least .1c (10%). You HAVE to get get batteries to 14.6v and hold that voltage until the amps going in taper below .5% (1a) minimum everyday.

Even if you have 25 amps of solar it takes many hours to fill a lead acid battery. Like 8+ hours. The sun is not out long enough this time a year to charge them no matter how many panels you have.

With only 1hr of sunlight your options are to get a battery charger or get a lifepo4 and at least 2 more panels....or lower your load.

Thanks for the answer, my loads are normally around 100w for that same problem, with the sun directly the most amps I can get into the batteries are 12A, but normally the charger sends around 0.5-1.5A (1:30pm to 6pm), 1-3A (7am to 9:30am) and 4A-12A (9:30am to 1:30pm) those are roughly the numbers.

 

[Ped]

Only because theres not enough sunlight. Very different.

and because where I live I only get like 1hr of full solar, my panel is behind the bars of a 2nd floor balcony and cant get it installed in the roof

Again you need DOUBLE those amps for double to tripple the time. Watch your voltage. It will take at least 4hrs to reach 14.6-14.8v then your controller will go into absorption. The max it can do is 3hrs which is not enough. But since you might go another full day it could work otherwise set float voltage to bulk voltage effectively turning the controller into a 2 stage bulk/ab.

The formula for NEW AGM recharge times which has many times less resistance and much better efficiency is

(Dod/100) x (ah/c) + 3ab × 1.25

Plugging your numbers in

50% dod - .5 x (225/12) = 9.4 + 3ab = 12.4 x 1.25 = 15.5hrs to reach 100% soc.

Doubling the solar gets 9.6hrs. But since your not staying in absorp long enough and you have FLA's it will be even longer. Like 1.5x.

 

[terry98]

What about the battery roundness I think its a bit swollen...

 

[terry98]

Only because theres not enough sunlight. Very different.



Again you need DOUBLE those amps for double to tripple the time. Watch your voltage. It will take at least 4hrs to reach 14.6-14.8v then your controller will go into absorption. The max it can do is 3hrs which is not enough. But since you might go another full day it could work otherwise set float voltage to bulk voltage effectively turning the controller into a 2 stage bulk/ab.

The formula for NEW AGM recharge times which has many times less resistance and much better efficiency is

(Dod/100) x (ah/c) + 3ab × 1.25

Plugging your numbers in

50% dod - .5 x (225/12) = 9.4 + 3ab = 12.4 x 1.25 = 15.5hrs to reach 100% soc.

Doubling the solar gets 9.6hrs. But since your not staying in absorp long enough and you have FLA's it will be even longer. Like 1.5x.

Damn... so at least 3 days waiting for the batteries to charge... well at least I could try setting the voltages as you say and turn it into a 2 stage charger.

 

[Ped]

The batteries are probably toast now but sure try that. If I were you Id go get a cheap single marine battery. That will match your system much better and stay much healthier.

This is exactly why we all want and are willing to pay for lifepo4. None of this stuff applies. What you take out you can put back in without needing to hit 100% charge.

 

[terry98]

I still have warranty and I dont have a wallmart in Dominican Republic xD, I could get a 12v100Ah flooded battery though

 

[Ped]

Youre that close to equator and only getting that few sunlight?? Damn. But yeah that sounds like a good plan to return them now. Then keep an eye on that charge voltage and getting to that magic number.

 

[terry98]

Youre that close to equator and only getting that few sunlight?? Damn. But yeah that sounds like a good plan to return them now. Then keep an eye on that charge voltage and getting to that magic number.

if... and only IF... I could get my panel to the roof of the apartment I would not have any of these problems, at least 15amps al day assured xD but the owner and some other neightbors in the building don't like the idea... one of the reasons I plan to move soon..

 

[Ped]

Im thinking if you can get 2 12v batteries in exchange you can make a dual bank with a selection switch. Use one while other charges. Switch back and forth every other day. Kinda kill 2 birds with one stone since youd be charging a much smaller battery at a time.

 

[SolarRat]

Today I noticed some sulfation in the positive lead and a bit of roundness above the battery and I dont know what can I do.. before using the battery I noticed that it measured 12.9v for 2 days, I don't really know if they were fully charged or if the controller can get them to float voltage. Any ideas or help???

I don't see any complaints about still providing adequate power? The corrosion is normal, use dielectric grease to reduce this. 12.9v is great at rest. If everything is working as usual I don't think you have a problem? Sure, you should have more charge amps, but you don't, so if it works thats all that matters.

It's working as designed, as far as we know from the provided information. Why is everyone here so quick to blame batteries?

 

[Ped]

Because hes getting 200w a day into a 225ah bank of FLA's. Thats like feeding a dog a cracker a day and wondering why everyones concerned its not moving.

 

[terry98]

I don't see any complaints about still providing adequate power? The corrosion is normal, use dielectric grease to reduce this. 12.9v is great at rest. If everything is working as usual I don't think you have a problem? Sure, you should have more charge amps, but you don't, so if it works thats all that matters.

It's working as designed, as far as we know from the provided information. Why is everyone here so quick to blame batteries?

thanks, I can rest a bit, but what about the bulge above the battery, it's just a bit though, a friend said that it is normal also... I dont know its the first time that I work with this.

 

[SolarRat]

what about the bulge above the battery

Pics or it didn't happen

 

[SolarRat]

Because hes getting 200w a day into a 225ah bank

Right, and that is a design problem not a bad battery. He said he lets it charge a couple days between uses. For all we know he only draws 300w replaces it with 400w. We have no idea. It all sounds normal to me unless he's complaining about run-time, which he hasn't yet.

 

[terry98]

Pics or it didn't happen

ok, I'll try to send the pictures tomorrow with more light.

 

[terry98]

Right, and that is a design problem not a bad battery. He said he lets it charge a couple days between uses. For all we know he only draws 300w replaces it with 400w. We have no idea. It all sounds normal to me unless he's complaining about run-time, which he hasn't yet.

well no, I know about the limits since the begining for not having as much sun as I'd like, but I know I can run ~100w for almost 10hrs to get the batteries to 50% dod and then I can forget about using them again xD but I totally got crazy today when I saw the corrosion (which I thogh to be sulfate) and the bit bulge..

BTW.. reading I found that corrosion in the black lead is undercharge and in the red lead is overcharge, I found mine in the red (+) lead.