I'm unfamiliar with your model of camera trap, so this may not be suitable for you. I've been using NiMH batteries in a couple of camera trap models that have two linked banks of four batteries, but have in fact used it as a single bank of five batteries. In my case the batteries are lined up parallel and individually held with a spring connector at the negative end, so I have been able to easily connect a link wire to rewire it into a bank of five batteries.
1 2 3 4 1 2 3 4
The left + bank1 is internally connected to the left positive of bank2 and the right negative to the right negative.
Therefore 4*1.5V=6V for standard batteries
and e.g. 4*1.3V =5.2V for NiMH
With recently recharged batteries the infrared illumination would not work.
Bank1 just put NiMH in positions 1,2,3
Bank 2 NiMh batteries in 3,4
Then use a link wire to connect -ve terminal on bank1 battery3 to +ve on bank2 battery3.
The five batteries provide between 6.8 and 6 volts as the batteries discharge and stops the camera trap shutting off while there's still plenty of energy in the batteries. It also means there is no problem with the IR leds.
Hopefully this is helpful to you and maybe others. Let me know if you'd like more details.