Canon PowerShot S1 IS User Manual page 18

While it is possible to use AA-size nickel-cadmium
batteries, performance is unreliable and their use is not
recommended.
Never mix unused and partially used batteries.
Always load four fresh (or fully recharged) batteries
at the same time.
Be careful to load the batteries with their positive (+)
and negative (-) ends in the right direction.
Never mix batteries of different types or from
different manufacturers. All four batteries should be
identical.
Before inserting the batteries, wipe the battery terminals
well with a dry cloth. Oil from one's skin or other dirt may
cause a considerable reduction in the number of
recordable images or reduce usage time.
Battery performance deteriorates at low temperatures
(especially with alkaline batteries). If you are using the
camera in cold areas and batteries are running down
faster than they should, you may be able to restore
performance by placing batteries in an inner pocket to
warm them up prior to use. But be careful that you don't
put the batteries into a pocket together with a metal key
chain or other metallic objects, as these objects may
cause batteries to short-circuit.
16 1. Preparing the Camera
If you do not plan to use the camera for a long time,
remove the batteries from the camera and store them in
a safe place. Batteries may leak and damage the camera
if left installed during prolonged periods of non-use.
WARNING
Never use damaged batteries or batteries whose
outer seal is completely or partially missing or
peeled off, as there is risk that such batteries may
leak, overheat, or burst. Always check the seals on
store-bought batteries before loading them, as
some batteries may come with defective seals. Do
not use batteries with defective seals.
Never use batteries that look like this.
Batteries with all or part of the seal
(electrical insulation sheath) peeled off.
The positive electrode (plus terminal) is flat.
The negative terminal is correctly formed
(protruding from the metal base), but the
seal does not extend up over the edge of the
metal base.