Sorry, I got confused, and thought you wanted the control the other way around – – so that the nonnetworked device became a switch on your smart things network.
In order to be able to have SmartThings cut power to the battery operated device, there’s one method that’s very straightforward, but It might be too expensive for many applications if you want to still power everything by battery.
Step One: Use a “Battery Eliminator” to convert the original device to an external power source
First You just use an adapter that converts a battery powered device to mains powered device. This has a form factor very similar to the Bluetooth one that you found – – there’s a case that looks like a battery that fits into the battery compartment, but in fact it just becomes a conduit for outside power. (Some of these also require adding dummy batteries to fill empty slots, but you can probably get one that will exactly fit the batteries you’re replacing.)
Step Two: add a radio to the external power source
If you then plug that adapter into an RF pocket socket, you have what you wanted: SmartThings control of the battery operated device.
Of course, you might not have mains power available where The battery operated device lives if it’s an outdoor lamp.
So then You can put a zigBee or Z wave relay on that power conduit and now you can shut the battery device on and off remotely.
The only question remaining is what power should you use to power the device if you didn’t just plug it in? You’ll need to connect it to another battery pack, as long as there is also enough power to run the network to relay. It’s usually that battery pack that makes everything expensive, depending on the draw needs of the original device and the amount of weatherproofing required.
battery eliminators are widely available
Some people build their own version of the power conduit, but they’re widely available for purchase. Typically sold for games or baby equipment where the adults in the house get tired of continually replacing batteries. It’s often called a “battery eliminator.”
Here’s just one example from Amazon. Again, using this is only the first step – – it’s what you then connect that battery eliminator to that gives you your RF control. For example, if you just plug it into a Z wave or zigbee pocket socket, you’re done. You turn the pocket socket on and off, it turns the battery powered device on and off. But if you need it to still be battery powered, you then need to find a power source for the conduit.