Can Orion TR Smart discharge main battery?

Hello!! I have just installed an Orion TR Smart in my camper van acting as a charger of the second battery when the engine is turned on. I have seen that the Bluetooth is always connected and the voltage of the car battery every day falls 0.10V aprox. If I don’t use the van in one month could the booster discharge the car battery???

Can I install a switch in the positive wire that connects the Orion and the main battery for turn it off when I don use my van??

Thanks for the help!!!