Post by Stiggy on Sept 15, 2011 12:23:52 GMT
12 volt lead acid batteries are fully charged when they reach 14.7-15v.
After charging they will settle down and read around 12.9v
2 stage chargers switch to a float voltage of around 13.8 once peak is reached.
Batteries is series need to be balanced.
4x12=48 so peak charge for the pack of 4 will be 4x15=60v.
If the batteries are not balanced then it is possible to over charge 3 whilst the weaker or lower charged battery will be holding the charger on as it waits to get to 60v.
3 could be being over charged at say 15.5v=46.5 or more whilst one is poor and has still only reached around 12.5 The total of 49v being one volt below the charger cut off voltage.
It is therefore important to test individual batteries in a pack whilst on charge to see if any are more than one volt adrift from the others. If 1 reads more than one volt different to the other 3 then it would be best to turn off the 48v charger and connect a 12v charger to the low battery for an hour or so. Assuming the battery that was low is still in good condition then it can be put back in to service with the others after it has been charged separately. Mark it suspect so you can check for balance next time and see if the same one is off. You will never get them all exactly the same but often the float voltage output from the charger will balance batteries up as the trickle charge is used to get batteries up to peak capacity.
Hope this helps. Regards Stiggy
After charging they will settle down and read around 12.9v
2 stage chargers switch to a float voltage of around 13.8 once peak is reached.
Batteries is series need to be balanced.
4x12=48 so peak charge for the pack of 4 will be 4x15=60v.
If the batteries are not balanced then it is possible to over charge 3 whilst the weaker or lower charged battery will be holding the charger on as it waits to get to 60v.
3 could be being over charged at say 15.5v=46.5 or more whilst one is poor and has still only reached around 12.5 The total of 49v being one volt below the charger cut off voltage.
It is therefore important to test individual batteries in a pack whilst on charge to see if any are more than one volt adrift from the others. If 1 reads more than one volt different to the other 3 then it would be best to turn off the 48v charger and connect a 12v charger to the low battery for an hour or so. Assuming the battery that was low is still in good condition then it can be put back in to service with the others after it has been charged separately. Mark it suspect so you can check for balance next time and see if the same one is off. You will never get them all exactly the same but often the float voltage output from the charger will balance batteries up as the trickle charge is used to get batteries up to peak capacity.
Hope this helps. Regards Stiggy