Replacement batteries for Canon cameras

[MSkinner]

I've just picked up an IXUS 100 after using an IXUS 80 and I'm wanting to pick up some backup batteries. The IXUS 80 I used had one Canon battery, and two no-name replacement batteries. I noticed that even though the no-name batteries were 1500mah (almost double the Canon battery), they still didn't last as long as the Canon battery, and took less than half the time to charge.

Can anyone shed some light on this for me? Is there a particular brand of aftermarket battery that is better than another? Am I better off paying nearly $50 more for a single Canon battery than 3 aftermarket ones?

Cheers,

Matt

[werdan]

I've found with Li-ion batteries that you need to really discharge them and recharge them a few times when you first get them, before they hold a charge properly.