[Li-Ion problems????]

I didn't keep receipts and the nearest service center says 'too bad'.

[Li-Ion problems????]

I have an 18v 1/23"Hammer/drill, 18v Recip saw, 18v circular saw that are fairly old.  When the batteries went bad, I bought two new 18V Li-Ion batteries and a third with charger with a new 1/4" impact driver. 

I loved them! light, long running etc.  Then, two of them no longer will take a charge!  One died in about 6 months and maybe 10-15 charges, the second about 3-4 months later. 

Is this something that is common?  Fixable?

I'm thinking of going to Ridgid, just for the lifetime warranty.  Three batteries at 120 bucks each and less than a year is not something I care to repeat.