convert discharge cutoff voltage to capacity percentage

[abdallah.91]

Hello guys,

please could anyone help me in selecting the voltage values correspond to 50% DoD, 60% DoD and 70% DoD? I recently bought 4 tubular 200Ah tall tubular Maxma batteries (Indian), and my Hybrid inverter (Must PH18-5048 Plus) is configured to as the attached figure shows, in addition I put the discharge cutoff voltage to 46.6V. does this voltage preserve a capacity of 40%? and are the absorption and float voltage values adequate?
another point someone told me that I should charge the batteries with less than 10% current amperage of its capacity (20A for 200Ah). so is it dangerous to keep the current flow open so I saw a 31A charging current.

Regards,

 

[12VoltInstalls]

put the discharge cutoff voltage to 46.6V. does this voltage preserve a capacity of 40%?

You shouldn’t go to 40%

What is the static, fully charged resting voltage of one of these batteries? Do you have advertised specs?
I don’t know what that battery is supposed to be.
if it is 12.8 nominal then 48.4-48.8 is 50% discharged, 51.2V+ fully charged.
46.6 would be 100% discharged

 

[abdallah.91]

hello,
the battery is flooded tall tubular, attached is its datasheet. what has made me confused is the vertical axis ticks of the status of charge characteristic in the last page of datasheet. you are right 46.6V supposed to be 0% or totally discharged.
please see the battery datasheet.

 

[RCinFLA]

Lead acid batteries have a lot of terminal voltage drop with load current so you will not be able to set a voltage cutoff to prevent discharge below a given percentage. Best way is to use a battery monitor that cumulates amp hours consumed. The terminal voltage drop with load current has a time delay. On a 200 AH lead acid with about 35 amp load it will drop close to 12.0v in a couple of minutes. It will recover in about 10-15 minutes if load is removed.

Lead acid charging rate is typically 15% of C20 amp hour rating.

On chart below, rested state is no load or charge current, for about 30 minutes, open circuit voltage that represents state of charge,