Battery gravity low while battery is fully charged

[lifebatteryonthego]

Hello

I have charged batteries full and they hold voltage and work but when I measured gravity its like they are not charged.

Does it mean that hydrometer is reading faulty or I need to increase water level inside cells.

Battery looks like it have enough water just in case could it be this?

 

[Mattb4]

Among the possibilities are:
The SG reading is correct and your battery is at a low state of capacity regardless of the voltage reading.
The SG reading is incorrect and you need a different hydrometer or different technique for using it.
You just added water and it has not had a chance to be converted into acid during a charge session.

About the best way to know is to charge the battery full and conduct a load test.

 

[lifebatteryonthego]

I haven't watered batteries yet since they look like have enough water...I am at moment doing equalize charge to them since Inverter showed like full charged them also voltage same thing so probably equalize charge will help something and I can find another hydrometer and test again.

 

[OzSolar]

Does it mean that hydrometer is reading faulty

Very unlikely but be sure you are using it correctly.

I need to increase water level inside cells.

No that's not it


Tell us more about the size of your batteries and the amps you are charging them at if you don't mind. I suspect you've got undercharged batteries and need to charge to them back up until the SG is above 1270.

Voltage is a poor way to guess at state of charge. When the batteries are badly sulphated they will show a good voltage but SG will be very low. Always trust the SG over the voltage.

 

[Nadad]

Among the possibilities are:
The SG reading is correct and your battery is at a low state of capacity regardless of the voltage reading.
The SG reading is incorrect and you need a different hydrometer or different technique for using it.
You just added water and it has not had a chance to be converted into acid during a charge session.

About the best way to know is to charge the battery full and conduct a load test.

 

[Nadad]

Among the possibilities are:
The SG reading is correct and your battery is at a low state of capacity regardless of the voltage reading.
The SG reading is incorrect and you need a different hydrometer or different technique for using it.
You just added water and it has not had a chance to be converted into acid during a charge session.

About the best way to know is to charge the battery full and conduct a load test.

the four terminal cells of my 2 tubular batteries hardly give SG values above 1.260, one of these cells in particular gives erratic readings. If i have to equalize, for how long and at what current? And please can you explain how one can perform a load test? The battery capacity is 220ah each

 

[Mattb4]

You can get load testers that are set to a certain amperage amount and battery low voltage point. They run until battery reaches that point. They display run time and ah.

However you can simply wire your batteries to any consistent amperage load like a small heater, heat lamp or similar and time how long it takes your battery to reach low voltage. Say you draw 10amps for 20 hours. That would be 200ah. If your battery is rated at 220ah you are within the Ballpark.

 

[Nadad]

You can get load testers that are set to a certain amperage amount and battery low voltage point. They run until battery reaches that point. They display run time and ah.

However you can simply wire your batteries to any consistent amperage load like a small heater, heat lamp or similar and time how long it takes your battery to reach low voltage. Say you draw 10amps for 20 hours. That would be 200ah. If your battery is rated at 220ah you are within the Ballpark.

Thanks for the prompt response. But just for clarity, do I do this with the batteries connected in series or individually? And what is your advice if they fall shot?

 

[Mattb4]

Thanks for the prompt response. But just for clarity, do I do this with the batteries connected in series or individually? And what is your advice if they fall shot?

You want to test individually to find if you have a weak battery. If it falls real short (say you have only 25ah) it likely means that it needs replacement.

 

[RCinFLA]

When a lead-acid battery gets hard sulfation due to not recharging for some time, the hardened sulfate crystals will not recharge.

This ties up sulphur in lead-sulfate that cannot be returned to electrolyte as recharged sulfuric acid causing electrolyte SG to be lower.

You will have a loss in total capacity. Best improvement that can be accomplished is to use equalization charge vigorous gassing to break loose hardened lead sulfate off surface of plates causing it to drop to bottom of battery.

You will not get SG back to normal levels but at least you clear the surface of plates so they can contribute to discharge capacity.

You can add a little higher concentration sulfuric acid to electrolyte to get SG back up, but you must make sure you have gotten fullest recharge first. Adding acid is not recommended and changing all the electrolyte out is usually not worth the effort and expense.

 

[Nadad]

When a lead-acid battery gets hard sulfation due to not recharging for some time, the hardened sulfate crystals will not recharge.

This ties up sulphur in lead-sulfate that cannot be returned to electrolyte as recharged sulfuric acid causing electrolyte SG to be lower.

You will have a loss in total capacity. Best improvement that can be accomplished is to use equalization charge vigorous gassing to break loose hardened lead sulfate off surface of plates causing it to drop to bottom of battery.

You will not get SG back to normal levels but at least you clear the surface of plates so they can contribute to discharge capacity.

You can add a little higher concentration sulfuric acid to electrolyte to get SG back up, but you must make sure you have gotten fullest recharge first. Adding acid is not recommended and changing all the electrolyte out is usually not worth the effort and expense.
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thank you so much. this will go a long way.