[Leica] Cheap M8 Batteries Going Bad?

[rbaron at concentric.net (Robert D. Baron)]

After initially buying just one extra Leica-branded battery for my M8, a 
couple of months ago I decided to order four extra third-party batteries 
(substantially cheaper) from a Hong Kong seller on eBay who a few other 
LUGers had said they had success with.  I now find three of the four 
will no longer take a full charge.

Specifically, I put them in the Leica charger and they seem to be 
charging fully, but when I put them in the camera two of them just show 
one bar (out of three bars) and another just shows two (the fourth one 
shows all three, or full).

I have not been using the batteries very often and I can understand if 
they would run down after a period of non-use, but I'm disturbed they 
won't now seem to take a full charge at all.

The price ($20 versus around $100) was pretty attractive, but the 
product may turn out to be worth what I paid for it.

Has anyone else had this sort of experience?

--Bob