Canon NB-4L Battery Pack Review

I use three batteries in rotation, as I am frequently travelling in places where there is no electricity. When I traded in my old PowerShot S410 for a new PowerShot SD750 I took a chance on buying two generic batteries ($12 instead of $42).
Both generics were slightly less than perfect, in that they would regularly activate the 'low battery' icon/light even when they were fully charged. Occasionally, they would even evoke the 'change battery' message. On these occasions I had to open the battery compartment, partially remove the battery, then re-install it, in which case I could now proceed to take pictures with the same battery.
My sense was that the total battery life of the generics was not dramatically shorter than the Canon original, although I did not attempt to measure this precisely.
As soon as I was able (about a month after I bought them, as I was travelling at the time) I returned the generics to Amazon and paid full price for the Canon original. Although the generics could be 'worked around' it wasn't worth it to me, as I discovered I was more interested in taking photos than in saving $30 (times 2).
See more reviews about: Canon NB-4L Battery Pack for the SD400, SD630, SD600, SD750, SD1000 & TX1 Digital Cameras