[Gerry Zagorski]

That is the likely issue Keepers..... If you let those batteries lay around too long fully discharged they can fail prematurely.

It's always best to store them when not in use fully charged and even if you don't use them, charge them once a month. This is especially true of NICAD batteries... You should also make sure and condition any new batteries when you first get them... The way you do that is to fully charge and fully discharge the battery a few times before you put it normal use.

If it is a NICAD you might want to see if you can get a Lithium Ion battery as a replacement instead but that might also force you to have to get a different charger too.... These batteries hold a charge better, last longer and don't suffer from some of the memory charging issues you get with NICADs