Once upon a time... Lowepro made the D-RES series of camera pouches. I had one of the smaller ones. It held every one of my AA battery pocket cameras and had plenty of internal pockets for extra batteries. With the AA cameras I had a spare set of rechargeables and a spare set of lithiums to cover the all too common loss-of-capacity-without-warning eventuality of AA rechargeables.
Then Lowepro stopped making the D-RES, and mine wore out. And Lowepro's more versatile bags with internal pockets were all focused around the ultra-compact end of the market. Canon make a great camera in the SX100-150 series, but there isn't any longer a bag that has internal pockets and fits the camera easily.
On the right there you have a Dashpoint 20, about the smallest pouch that will fit a SX1xx. But, there are no pockets except for a small elastic one for a spare memory card. So no room for spare batteries.
What else is available? Well I tried a few different things. The latest is seen on the left - the Apex 60. It's very nice, but as you can see it's a lot wider. The size of it is an embarrassment to carry on your belt compared to the camera, which will fit in the pouch two directions with lots of spare space. It is designed with the Canon GxX series in mind, which is significantly larger.
The problem with Lowepro's range is there aren't a progression of sizes. The similar Apex 20 and 30 models are nearly the same size, then there is a big jump to the Apex 60.
Bearing in mind I am using an SX150 at the moment until I decide what should replace it, I am using the Apex 60 until I work out the answer to that question. That may well be the SX170 back in the Dashpoint 20 or something smaller, again.
