How to restore my lead acid batteries - Does Equalization work ?

[lifebatteryonthego]

I have 8x 12V 225 AH FLA batteries used for more than a year they are combined in two sets of 48v then parallel connection to Inverter.

I have discharged them many times to 30% then in morning they always have been charged from solar panels sometimes full completely and sometimes to 80%.

I can notice now that they are weaker because don't last long like they did before - I have read for equalization but haven't tried equalization so does it really work - how much "repair or restore" I can except from my batteries ?

My battery chemistry is Sb/Ca and they have enough water...also this batteries have discharge rate of 1300 A

 

[Charleswgibbs]

Have you checked the resting voltage of each battery individually to see how close they are to each other? It's possible they are out of balance, if so break the bank down and fully charge each one individually before putting back in series.

 

[acdoctor]

Equalization does work. It should be done at least monthly though on batteries that are heavy used. The purpose is the remove sulfates to expose plates and balance cells.
Specific gravity should be checked before starting and during. Equalization should be done with the caps off and proper ventilation. You should charge until charging amps drops off at the end of absorption. Then increase the voltage to the manufacture recommendation usually 60 to 64 volts. If successful amperage will increase. Keep an eye on the battery temperature. If they reach 100 degF I stop for the day.
A while back my 10 year old tractor battery was cranking the tractor slowly. When I checked it I was embarrassed. The water was low, nearly to the plates. The water there was, was cloudy, the plates were white! The specific gravity was 1.9 or something.
I added some water, and charged it for 2 14 hour days with a constant voltage charger before the amperage start to climb. Charged for another day until amperage dropped to nothing. Then I increase the voltage 16 volts and charged until it reached 100 deg let it rest overnight. Then charged again at 16 volts to 100 deg. The following day the specific gravity was 2.80.

 

[lifebatteryonthego]

Have you checked the resting voltage of each battery individually to see how close they are to each other? It's possible they are out of balance, if so break the bank down and fully charge each one individually before putting back in series.

Yes they are in balance since I check them regularly and also have device which balances them and now recently I have them in set of 2P4S connection so they are in good balance and no battery is weaker than other...its just year of use and times that I discharged them so if equalize charge of 2-3 hours would help them to recover then it would be very helpful for my use case.
450 AH 48v is around 21kwh so having at least 12kwh in my case would be very good.

 

[lifebatteryonthego]

Equalization does work. It should be done at least monthly though on batteries that are heavy used. The purpose is the remove sulfates to expose plates and balance cells.
Specific gravity should be checked before starting and during. Equalization should be done with the caps off and proper ventilation. You should charge until charging amps drops off at the end of absorption. Then increase the voltage to the manufacture recommendation usually 60 to 64 volts. If successful amperage will increase. Keep an eye on the battery temperature. If they reach 100 degF I stop for the day.
A while back my 10 year old tractor battery was cranking the tractor slowly. When I checked it I was embarrassed. The water was low, nearly to the plates. The water there was, was cloudy, the plates were white! The specific gravity was 1.9 or something.
I added some water, and charged it for 2 14 hour days with a constant voltage charger before the amperage start to climb. Charged for another day until amperage dropped to nothing. Then I increase the voltage 16 volts and charged until it reached 100 deg let it rest overnight. Then charged again at 16 volts to 100 deg. The following day the specific gravity was 2.80.

Wow very promising...problem is I had no backup generator so now I have it and my inverter has 80A power to charge from AC so I can charge it during day with solar then activate generator and push in equalization.
But so far I have seen most inverters have 58.6 equalization voltage for charge which is 14.65 per battery if I choose manually 60 volts its like 15+v per battery.

 

[OzSolar]

Have you checked the SG of each cell? That's really the best indicator.

If you can find the equivalent of the below chart for your battery you manually program the appropriate equalization numbers into your inverter.

 

[Vigo]

I think what he’s referring to is some inverters may not be able to be set high enough to follow manufacturer settings. I havent found a way to get my Growatt spf5000s to go past 58.x even though on that chart i should be doing around 60.

 

[chrisski]

My battery chemistry is Sb/Ca and they have enough water...also this batteries have discharge rate of 1300 A

I am unfamiliar with this hybrid antimony calcium lead acid battery.

Can you share the specific battery. Not much pops up on my web search except gel or agm batteries.

 

[time2roll]

Yes the equalization may help. Run it an hour a day and see how it goes for up to a week. Then schedule it once a month.

Probably need 2x battery power.

 

[OzSolar]

I think what he’s referring to is some inverters may not be able to be set high enough to follow manufacturer settings. I havent found a way to get my Growatt spf5000s to go past 58.x even though on that chart i should be doing around 60.

Ahh..good point, yes that silliness of an inverter not being able to equalize FLA is all rather new to me.

Here's a suggestion: Many years ago a wise engineer that authored FLA manuals informed me that you can trade the higher voltage and short times (hours) of equalization for a lower voltage and longer periods (days) and still end up with a healthy battery.