Here is a link: http;//www.nativeoutdoors.com/scouting_accessories.html
Scroll down to "Stealth Cam External Battery Kit". It shows a picture of the charger. Now if you can enlarge the picture you may be able to compare it to what you have. Good luck.
The battery tender may work as long as it does not put out too high an amperage. I use it on my motorcycle battery. This battery contains liquid (sulphuric acid and water) and not a jell type. The battery tender in my case will shut down when the battery is charged. I purchased my battery tender at WalMart.