I have a Skil Portable drill with two battery paks,
(Skil No.92927 12 volt Super Power Pak).
One works fine but the other puts out only 8.5 Volts
after charging.
  I've discharged it several times down to about 3 volts 
and recharged it with no effect.One or more of the "C"
batteries was defective.
  After about 6 months,I decided to see what was in it.I 
took it down to my table saw and carefully cut off one side 
about 1/16" at a time until I had an opening.Then I used a 
screwdriver to open it all the way up.The cover came apart very 
easily and exposed the whole assembly.
  Inside I see 10 cardboard covered " C " batteries,two sets
of two and one set of 6. A voltmeter check shows no voltage in
any.Must have all discharged over 6 months.I'll try to find the
defective batteries and cut the welded flat strips to give me sets
of 2 batteries for flashlights.
  I also found an RC parallel circuit in the main leads.
The capacitor is a small metal can about 1/4" by 3/16" by 
3/4" long.The writing says "PEPI C " and " 26H+046G ".
The resistor was a common tubular clay type ,about 1/4 Watt,
with color bands that I couldn't read very well but measured 
0.4 ohms on my digital meter.  I wonder why that was in there.
 
Very interesting.
 
 

--- Maximus 2.02