Rechargeables always seem to come partially charged.
As I understand it, in order to get the best performance and life out of a rechargeable battery, they should be fully charged then fully discharged for a couple of cycles, then discharged occasionally if not discharged during normal usage.
So receiving the battery partially charged and giving it a full charge would theoretically reduce the life of the battery as it would need discharged before its first full charge? But one has to follow the instructions.
I regularly check the voltages of all my rechargable batteries before and after charging, using a simple voltmemeter. It gives an accurate reading of the voltage in the battery...and is also shows if you have got a 'dud' one.
Aichbee testing a battery off load is pointless. A battery needs to be On Load to get an idea of the voltage as there is a volt drop within the battery. On Load voltage will always be less than Off Load.
The theroretical representation of a battery is a DC generator with a resistor in series beween the terminals.
romanby1 - if I check, say 100 batteries, off load, I can very soon eliminate the 'duds'.If the actual voltage readings, off load,are below what they should be, I charge them up.Invariably, after an overnight charge, the voltage readings are higher, ie..they are 'charged up'. What could be simpler?
A battery measured off load can give a voltage that appears to suggest that it is OK but this is a meaningless test, it can still be dud in terms of output. That is why a resistance tester must be used when testing vehicle batteries.
OK - respected forum members. You have convinced me! On a similar note; can my simple ammeter/voltmeter be used to check the output current and output voltage from a charger, off load, to see if it matches the actual information on the charger?