AH of Battery

How old are the batteries? They don't live for ever

three years back the battery installed

Time to start looking for new ones then.

thanks a lot

I have 5 nos of 6v,150 AH battery. can I use 6v, 250 AH battery instead

If you only have 30V immediately after disconnecting the charger, what is your charge voltage? You may have been undercharging those poor batteries for their entire lives!

I would expect the charge voltage to be around 34 to 36V to maintain the batteries at full charge. If they have been floating on 30V for several years they may or may not recover when properly charged.

Before swapping them out, I would check with the battery manufacturer and find the recommended charge V for the stack and try charging them and discharging them for a few cycles to see if they recovered sufficient capacity for the application before I replaced them.

Just sayin'!

So,what we can do for a Float battery to keep it healthy for so long years ?

I am not a battery expert but I met one once. ;)

I would check with the battery manufacturer to find out what the appropriate voltage and current is for Float, Equalization and Charging after a loaded period.

Batteries of different manufacture have slightly different chemistry so use the specifications for the batteries you are using.

Temperature also has an effect on permissible charge voltage and current

Float charge is sufficient to maintain the battery at its present state of charge. So, float is just enough to keep the battery where it is.

Equalization is intended to equalize the charge across the battery's cells. Each cell in a battery has slightly different characteristics from the other cells. Over time, some cells will discharge more than others and float charging does not correct this imbalance. The equalization charge is intended to match the charge state of all of the cells. The equalization voltage is too high to maintain continuously. If you do, you will cook out the water or over charge the battery and damage it.

Charging after a loaded period can be handled by an equalization charge, but it is best handled by a charging period with monitored voltage and current. This charge cycle may be followed by or include an equalization charge and then the system needs to go on float charge.

Some systems automatically equalization charge on a schedule. Others, require the equalization charge to be manually initiated.

In a lead acid battery bank, with open cells, the electrolyte's specific gravity in each cell is used to determine the charge state of the individual cells. If the variance between cells becomes too great, an equalization charge cycle is indicated to get them back in line.

Have FUN!

TT3