Before you respond, please understand, I ALREADY HAVE THE 6v TIMER AND MOTOR.

Doing some research, I understand that 12v Batteries hold a charge and last much longer than their 6v counter part. I am building a charge box for a feeder and what I would like to do is this:

12v Solar charger into 12V battery. 12v battery into 6v converter. 6v converter into Timer and motor batteries, and also into 2 different feeder mounted cameras.

I want to do it this way so when I do upgrade to the 12v spinner all I have to do is do a quick rewire past the converter. I have never done ant type of wiring that used a converter. Thoughts? Am I on the right track?

I run two 6volt batteries in all my 12 volt feeders. Because I have 6 and 12 volt feeders. I only have to carry one battery that away.

Yup^

Be careful running the motor off that converter! While the motor might only draw 1-2 amps once spinning, the startup current can be 30+ amps until the motor gets to spinning. If the converter has output current limiting, it could cause the motor to not start up. On the other hand, a stalled/stuck motor could burn up your converter before the fuse has a chance to blow if it doesn't have any output current limiting protection. A stalled motor draws the most current because there is no back EMF generated in the motor winding. This back EMF, when the motor spins, effectively reduces the current draw. It might "work", but wanted to point those things out.

Also check the Quiescent (no-load) current of the converter. Some of these can be 12mA or more. If you run the numbers (0.012Amps*12V*24hrs) = That is almost 3.5Watts per day just to run the converter with no load. Those tiny solar panels only output at best 1 watt and it is usually less because many aren't aimed optimally at the sun. Depending on your location, figure on average 4-5 solar hours per day (most days will be more but you have account for poor weather). So this puts your total daily output on average at 4-5 watts. It might work, but you may want to do a little math first so you don't have a dead battery after a month or two.

I personally like 12v because it spins corn out further.

Spend the $100 and get a 12 volt system. The motor is much larger, battery last longer and corn goes further.

I agree with this statement. But use two 6 volt batteries.