Aimpoint Comp Series Second battery compartment

I found these on Ebay it was just under $10 a pair. I bought two pair. I have two Pros and one C3. My work gun also has a Pro on it. My question is does this double my battery life or is the second battery a spare? I think it doubles the battery life. It came with no literature.

Before on the C3

http://i859.photobucket.com/albums/a...swsk4abd0.jpeg

After

http://i859.photobucket.com/albums/a...sy5zvfu3n.jpeg


http://i859.photobucket.com/albums/a...sfcr9viyn.jpeg

http://i859.photobucket.com/albums/a...sq0hseoxe.jpeg

http://i859.photobucket.com/albums/a...sfaevn5ee.jpeg

This is where I bought them.

http://m.ebay.com/itm/2-Pack-Aimpoin...=1279946666013

If I'm not mistaken, you have an onboard spare. Looks like foam insulation on the inside.

Thank you. I will have to take another look. I thought it was metal. A spare makes more sense to me. I would not think there was a need for a separator unless it was a spare.

Those are to keep a spare battery on hand.

Thanks Guys. I works great on the C3. I put one on my Pro and quickly realized the rubber bikini attachment was not going to work. I might cut it to fit. I have an email in to an Aimpoint dealer to see if they sell the bikini part that attaches to the battery compartment and the windage and elevation knobs.