guys need bit of help , dug out couple of deep cycle battery’s ready to put back on 110 charged them up for 24 hours and checked the voltage one is reading 12;26 and one 12,37 this seems a bit low ? Any thoughts are they toast or usable shouldn’t have let them drain down over winter , thanks
brian47
Well-Known Member
+1
A lead acid battery has three voltages which can generally indicate its state, although it's not a foolproof method. The fully discharged state is 1.8 volts per cell or 10.8 volts for the whole battery. The nominal voltage is regarded as being 2.0 volts per cell or 12 volts and a fully charged state of 2.2 volts per cell or 13.8 volts for the battery. So yes yours is slightly low.
The most accurate way to determine the state of charge of a battery is to use a hydrometer to measure the specific gravity of the acid electrolyte in each cell, but of course, that's useless for a sealed or gel type battery.
When charging, the voltage applied to the battery should be around 14.4 volts or 2.4 volts per cell and trickle charge at about the 13.8 volts mark.
The main problem with leaving a lead acid battery just stand is that the plates can become sulphated, that is a crusty kind of covering which can reduce the efficiency of the battery. In the past I have had some success with the use of "Batt Aid" tablets which purport to reduce or remove sulphation, but once again the battery needs to be a liquid type with access stopper on each cell.
A lead acid battery has three voltages which can generally indicate its state, although it's not a foolproof method. The fully discharged state is 1.8 volts per cell or 10.8 volts for the whole battery. The nominal voltage is regarded as being 2.0 volts per cell or 12 volts and a fully charged state of 2.2 volts per cell or 13.8 volts for the battery. So yes yours is slightly low.
The most accurate way to determine the state of charge of a battery is to use a hydrometer to measure the specific gravity of the acid electrolyte in each cell, but of course, that's useless for a sealed or gel type battery.
When charging, the voltage applied to the battery should be around 14.4 volts or 2.4 volts per cell and trickle charge at about the 13.8 volts mark.
The main problem with leaving a lead acid battery just stand is that the plates can become sulphated, that is a crusty kind of covering which can reduce the efficiency of the battery. In the past I have had some success with the use of "Batt Aid" tablets which purport to reduce or remove sulphation, but once again the battery needs to be a liquid type with access stopper on each cell.
Yes a bit low. I would put them back on charge for another 24 hours let them settle and see if they hold a bit more. Nothing to loose by trying.
