I use the 2826/12 with a 5 cell 2700mah 25C Thunder Power battery or a 5 cell 2450mah 35C Zippy Compact battery.  That works great too.

I use the Phoenix 45 on 5 cells for years now with no problem on about 52 ounce 570 sq in airplanes.  I'm using a Hubin FM-9 timer and Cobra 2826/12 motor with a APC 13 x 5.5 WEP cut down to 12". Launch RPM is about 9600.  I've launch at as high a RPM of 10,300 with this set up and still no problems.

Joe,
Not sure what you are asking?

It's not about the power.  I use the 2826/12 with a 5 cell battery to get the rpm range I need.  If I used a 5 cell battery with a 2626/10 the rpm would be too high.  We must match the Kv of the motor with the cell count of the battery to get into the range of the rpm we want to run at.

I knew there was something to that.. so could this motor power up a good .60 size ship like a SV-11 etc. (approx. 680 sq in / weights about 68oz) with a 13x5.5 apc or a 3-blade 11x5.5?   I have an E-flite 32 already and was looking for something lighter with the same performance, then I saw the Cobra 2826-12 (1.5oz lighter). 

At what line length and then what rpm and then what watts   I ended up with the Cobra 3520-14 after looking at the smaller lighter 28 series for 64-65 foot lines and 660 - 675 sq in.

Joe,
Here is a spreadsheet that I use to figure out what a system would be capable of.  It has served me well for about 5 years now.  The shaded gray areas are cells that you input info in.  The rest of the spreadsheet is automatically filled in.  IMHO the 2826/12 motor would be too small for a 68 oz airplane.  Perhaps more suited to a 60 oz airplane max.

Watts per pound cell the minimum is 112.  I try for about 120.  It all depends on battery size, motor, prop, etc. 

The spreadsheet has your SV-11 numbers already plugged in.  Try experimenting with different weights, watts per pound, run time, etc to see how it all interacts.